Scientific Principles of Strength Training - Stimulus Recovery Adaptation PDF

CHAPTER SIX STIMULUS RECOVERY ADAPTATION SCIENTIFIC DEFINITION Stimulus-Recovery-Adaptation (SRA) describes the sequence of processes that occur during and after training; the very processes that cause improvement and increases in size and strength. It is a sport- science derivation of the much...

CHAPTER SIX STIMULUS RECOVERY ADAPTATION SCIENTIFIC DEFINITION Stimulus-Recovery-Adaptation (SRA) describes the sequence of processes that occur during and after training; the very processes that cause improvement and increases in size and strength. It is a sport- science derivation of the much older General Adaptation Syndrome (GAS) originally described by Swedish physiologist Hans Selye. Every training session and the period after it and before the next session can be described entirely by SRA. Please see the graph below. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 186 F i g u re 8 : S t i m u l u s - R e c ove r y -Ad a p t a t i o n C u r ve S T I M U LU S The stimulus is the period of time during which training itself actually occurs. Varied mechanical and molecular systems are disturbed during this time, causing both a depression of performance and a signaling cascade that prepares those disturbed systems for recovery and adaptation. Depending on the nature of the disruption, performance can continue to decline further and further hours and days after the stimulus itself. Functional muscle size is reduced for days after hard training as the immune system and satellite cells repair damaged muscle fibers, during which time they are partially unresponsive to activation and use. Similar processes occur in the nervous system, so that whole-movement performance can actually get worse over several hours and days after an overloading training session before it begins to recover. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 187 Within the adaptive limits of the body, stimuli that disrupt the most and depress performance for longest also tend to produce the most elevated adaptations, but the whole SRA cycle then takes longer to complete, which is a feature that will be further explored in later sections of this chapter. R E C OV E RY Immediately after the stimulus is presented, recovery systems begin to heal homeostatic disruptions and attempt to return performance of the system back to normal levels. If the disruption is large, it may be hours or days before some system performances even bottom out and begin their rise back to baseline levels. It is very important to note that during this time, further overloads can and will disrupt performance even further. If the additional disruption is within the system’s long-term ability to overcome, then an even bigger adaptive spike can be created once recovery is complete, which is the principle behind overreaching. If, however, one or a series of overloads is presented during recovery and their magnitude is too great for systems to overcome, an incomplete recovery with little or no adaptation can be the result. Outside of the occasional use of functional/planned overreaching, the implication is that overload training should be followed by periods of rest or non-overloading training in order to prevent interference with recovery. A DA P TAT I O N As recovery occurs, so does adaptation. Adaptation is technically measured as the degree of performance gain above the starting baseline at which the stimulus occurred. In fact, adaptation can be occurring Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 188 as soon as the stimulus has concluded or just after, and proceeds concurrently with recovery, but usually concludes after recovery as it is a more physiologically expensive and complicated process to make new tissue structures or re-arrange current ones for ability improvements. It is almost always easier to regain older performances than it is to establish new ones. During the time that adaptation is occurring, overloads can directly interfere with the adaptive process and curb the sum-total degree of adaptation gained from stimulus. This is a very important consideration, as it implies that outside of functional overreaching, training and rest must be structured in an organized fashion. Particularly, the combination of stimulus, recovery, and adaptation creates the necessity of what can be called the “session-rest-session” paradigm. Instead of just training randomly through the week or clustering way too much training way too close together and then taking the week off, the SRA principle creates the need to perform a calculated stimulus (training session) and allow sufficient time away from overloading disruptions (recovery and adaptation) before the next stimulus (training session) is presented. Put another way, the goal of training becomes to arrange a program such that the next training session occurs at the adaptive peak of the generated SRA curve of the previous session, and so on and so forth. This allows for the fastest rates of improvement as adaptations build on one-another, without training too early to disrupt further adaptations or too late so as to lose gains needlessly. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 189 F i g u re 9 : A r ra n g i n g P e a k - t o - P e a k S R A C u r ve s SYST E M - S P E C I F I C S R A C U RV E S Each time a stimulus is presented and an overload disrupts homeostasis, an SRA curve (as illustrated above) is generated. In reality, one SRA curve is simply an averaging of the multiple SRA curves that are generated with each session. Every time an overload occurs, each system experiences its own SRA curve, and on a different timescale. During powerlifting training, each hard session produces at least 4 distinct SRA curves noteworthy for this discussion, with each curve having different average durations: nervous system technical ability, hypertrophy, nervous system force output, and fiber alignment/connective tissue integrity curves. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 190 A. ) N E RVO U S SYS T E M : T E C H N I C A L A B I L I T Y C U R V E During a training session, the nervous system gets lots of practice on the technical execution of the lifts. Both central and peripheral nervous systems are involved in producing the sequence of muscle contractions and relaxations the cause the bones to move in the exact pattern desired. The more practice a session allows for, the more stimulus there is for technical improvement, but also the more fatigue is generated and the more the technique breaks down. At the end of a training session and for hours after, technical execution is worse than it was before the session. Within hours of the last session, however, recovery and adaptation produce a net improvement in technical ability. In most human movements (and definitely such relatively simple movements as the powerlifts), the adaptive processes that govern technique rarely need longer than a day to complete, and often much less time than that. We thus see a ubiquity of multi-day technical training within a week in almost all sports, and oftentimes multi-session training within the same day. If we were only seeking to improve lifting technique, we could train multiple times per day almost every single day of the week. If we just wanted to hold onto technique, several sessions a week would suffice, especially if the technique is well established. But of course we’re not only concerned with technique training in powerlifting, as hypertrophy and neural force production at the very least are equivalent if not more important concerns. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 191 F i g u re 1 0 : Te c h n i q u e S R A C u r ve B.) MUSCLE HYPERTROPHY CURVE Because the most fundamental underlying physiological effector of strength is muscle size, its SRA dynamics are of very keen interest to the construction of a powerlifting program. During an overloading session, muscle catabolism actually rises and size is lost! After a session, however, the FSR curve (fractional synthetic rate of muscle growth; the measured rate of muscle addition in the body) rises to positive and stays elevated for what usually amounts to several days, and at least a day in most cases. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 192 Along with direct addition of muscle tissue, the pennation angle of muscle fibers also changes from training. The pennation angle of a muscle fiber is its angle relative to the tendon on which it pulls. Different exercises have different optimal pennation angles, so every time a new exercise is introduced, pennation angles begin to change in a process that can take weeks to complete. During the actual training session, pennation angle actually reverses its trend, but recovers and makes new gains afterwards. Pennation angle SRA curves generally run a similar time course to hypertrophic adaptations. The length of the SRA curve for muscle hypertrophy varies greatly based on the degree of homeostatic disruption, the fiber type of the muscles, the level of training of the individual, their muscle size, the muscle group trained and several other factors. However, this curve is usually measured in days, and if our only goal was to train for muscle size, we would overload somewhere between 2 and 4 times per week. Not ironically, smaller beginner lifters for whom technical and hypertrophic adaptations make the biggest difference are the same lifters to seemingly benefit the most from the highest frequency programming. More experienced lifters have more stable technique and are more resistant to muscle growth, and must thus rely more on the next two factors for improvements to their powerlifting abilities. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 193 F i g u re 1 1 a : F ra c t i o n a l S y n t h e t i c R a t e s a n d S R A C. ) N E RVO U S SYS T E M F O R C E O U T P U T C U R V E The nervous system has two functions of interest to us here, the one already mentioned is the coordination of muscle contraction and relaxation in a particular sequence so as to produce a certain movement pattern. This essentially can be said as the determining of the direction of body and thus barbell movement. The other function to be addressed is the magnitude of that movement. More specifically, how much force production the nervous system can signal the muscles to create. This is a property that can be trained, and it has been shown that experienced lifters of the same size as novice lifters can generate higher forces with the same muscle mass, owing in large part to the activity and Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 194 trainability of the nervous system. Every time this ability of the nervous system experiences overload (through high force contractions of the muscle and lots of them), it follows the SRA curve through short term depression, recovery, and adaptation. In the average case, the SRA curve for nervous-system mediated force output takes about a week to peak in adaptation, but the degree of variance seems high with bigger, stronger, more experienced lifters having SRA curves that are considerably longer, to the tune of two weeks at the higher volumes and intensities of training. If our only goal was to exclusively improve nervous system force production ability, we may present an overload only once per week or even more rarely. In fact, equipped lifters that present overloads greater than 100% of their raw 1RM do exactly that! The Westside system calls for overload training exactly once per week for each muscle group, which makes very good sense, given that the lifters there already have a good technical proficiency with lifts and the muscle to support them (sometimes bolstered by anabolics which can maintain muscle mass at low training volumes). Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 195 F i g u re 1 1 b : N S F o rc e P ro d u c t i o n S R A C u r ve D. ) CO N N E C T I V E T I S S U E I N T E G R I T Y C U R V E As heavy training occurs, connective tissues take on damage. This damage stimulates adaptive processes, but the recovery time is incredibly long due in part to the poorly vascularized anatomy of tendon, ligament, and bone. The stimuli of structural changes to connective tissue can depress the integrity of these tissues for weeks and months at a time before recovery even has a chance to break even. Progressively harder and harder training further and further degrades especially tendons, and only periods of lighter (hypertrophy or active rest) training can allow recovery and supercompensation to occur at best rates. If we Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 196 only trained for connective tissue adaptation, we might alternate weeks of insanely heavy loading with weeks of almost no loading at all. The ultimate illustration of SRA curve length in this case is the healing time of a stress fracture, for which months of limited activity are required. F i g u re 1 1 c : C o n n e c t i ve Ti s s u e I n t e g r i t y S R A C u r ve Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 197 R E L AT I V E M A G N I T U D E S O F S R A C U R V E S & TRAINING FREQUENCY Every weight training session always generates individual SRA curves for each specific category from the four list above. Every training session causes some technical improvement, hypertrophy, nervous system force production improvement, and connective tissue strengthening. But different forms of training lead to the elevation of magnitudes of certain systems more than others, in the following way: Light Session Technique Practice: technical neural adaptations receive the highest amplitude change in their generated SRA curve, thus experiencing both greater fatigue and greater adaptation. Hypertrophy Training: high volume training in the hypertrophy intensity range stimulates muscle growth SRA curves to rise the most, with other systems less affected. Strength Training: elevates force-production Nervous System (NS) curves the most, other qualities to a lesser extent. Peaking Training: training with low volumes at 90%+ intensity elevates technical and force-producing curves considerably, but probably elevates connective tissue reconstruction curves the most. In order to train for simply one system while ignoring all others, what we need to do is line up the next training session at the adaptive peak of the last training session’s SRA curve: Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 198 F i g u re 1 2 : Ti m i n g Tra i n i n g t o o n e S R A C u r ve Now, if we were to train for the expression of all of the above systems to be even, we could simply average the durations it takes all of the 4 system-specific SRA curves to reach a peak and time our training to those peaks: Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 199 F i g u re 1 3 : Ti m i n g Tra i n i n g t o a n S R A Ave ra g e For the average intermediate lifter, that might result in something like training each lift/bodypart once every 3-5 days or so. This would result in the decent general development of all systems, but would violate phase potentiation (see Phase Potentiation chapter for in-depth Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 200 discussion) and thus not be the best approach. Rather, we can structure training in such a way that all systems are trained, but certain systems are prioritized based on the needs of the training phase. Thus, we can bias our frequency to more accurately reflect our phase-specific training needs. For training to maximize technical development and retention, we can shift our frequency of training to one that is shorter than the all-system- average SRA curve, which might be anywhere from daily to 4x a week training for most lifters: F i g u re 1 4 : Ti m i n g Tra i n i n g t o E m p h a s i z e Te c h n i c a l D eve l o p m e n t Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 201 To maximize muscle size accretion (or prevent size loss while cutting), we’d be training a little less frequently than with technique-dominant design, but still between 2 and 4 sessions per week for the same muscle groups for most lifters: F i g u re 1 5 : Ti m i n g Tra i n i n g t o E m p h a s i z e H y p e r t ro h py Training for strength comes quite close to all-system-SRA average at 1-3 sessions per week for the same muscle groups/movements. Light sessions might be inserted as well to improve fatigue management and retain more hypertrophic and technical adaptations: Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 202 F i g u re 1 6 : Ti m i n g Tra i n i n g t o E m p h a s i z e S t re n g t h Training to peak with the highest possible intensities may be a lower frequency than the all-system-average SRA curve, but only slightly. This is because the all-system SRA curve is so heavily biased by the disproportionately long connective tissue-remodeling curves. Training for peaking might occur only once a weak or perhaps twice for the same movement/muscles, but can be interspersed with lighter sessions that promote technical and hypertrophic retention: Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 203 F i g u re 1 7 : Ti m i n g Tra i n i n g t o E m p h a s i z e P e a k i n g So far we have all curves accounted for except for those of connective tissues. Luckily, connective tissue SRA curves are only depressed with the frequent heavy training of the strength and peaking phases. During hypertrophy phases, active rests, and deloads for all of the phases, connective tissue SRA curves go through their recovery and adaptation phases. That’s right, connective tissue adaptations take so long that they go through a whole SRA cycle over a mesocycle or even macrocycle length, while technical systems on the other extreme take only hours to go through their SRA cycles! Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 204 P OW E R L I F T I N G D E F I N I T I O N The SRA principle, like all the principles so far and all the ones to come, can be put into powerlifting terms fairly easily. Because overload training a certain ability (technique, size, strength, peaking) during its recovery reduces its eventual benefit when recovery occurs, it’s important to give enough rest or non-overloading training time to the systems we’re training when we’re training them. On the other hand, waiting too long between workouts leads to a fall of the SRA curve back to baseline (and eventually lower if you really don’t train for a while), so there is such a thing as waiting too long. Secondly, the magnitude of the adaptation peak of each SRA curve is controlled in part by the size of the training stimulus (see graph below). For example, a very tough hypertrophy session can take 3 days for the whole SRA cycle to complete, while an easier one might take only 2 days. There are slightly more complicated issues on this matter that will be discussed in the next section, but the implication for powerlifting training is that multiple frequencies are ok, so long as you give more rest time between sessions if your sessions are harder (usually higher in volume is a big part of “harder”) than between the easier ones. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 205 F i g u re 1 8 : S e s s i o n M a g n i t u d e E f f e c t s o n S R A Ti m i n g In plain terms, hit the weights hard, rest, recover, and repeat. Improvements in ability occur during recovery and adaptation which mostly happen outside of the gym, and are merely stimulated with training. If you’re supposed to be resting and reaping the rewards while you’re training, you won’t get the best outcomes. On the other hand, if you’re resting while you’re supposed to be training, that will be equally bad. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 206 P R I N C I P L E I M P O R TA N C E R A N K There are two big reasons why SRA is not ranked higher up on the list of the most important principles: 1.) Training at any frequency that’s not insane (between once a day and once a week) generally trains all of the four systems and will produce good results, though possibly not the best results. If you don’t manage fatigue properly or present an overload properly, you will go nowhere fast, but if you train with at least a reasonable frequency and structure, you’ll at least be ok and make some long term gains. 2.) There are benefits as well as costs to the improper structuring of SRA curves and training frequencies. Improper structuring is a net negative, but the benefits of extreme choices make this net a smaller negative than violations of specificity, overload, and fatigue management. If training is too frequent but fatigue management is in place, functional overreaching can salvage some of the adaptations of such training. On the other hand, if training is too infrequent at various points, at least fatigue is very hard to sum up and each session can be massively overloading, which tips the scales back a bit, though not all the way. For the above two reasons, SRA violations, especially the milder ones will not make or break a program, and this is actually the first principle on our list that we can officially qualify as “not essential to successful training.” It’s not essential, but it’s probably the most important of the minor principles, and is thus ranked as fourth in our priority list. A program can be successful without good SRA dynamics, but the best programs accord carefully with this principle. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 207 I M P L I C AT I O N S & E X A M P L E S O F P R O P E R A P P L I C AT I O N O F S R A 1.) OPTIMAL FREQUENCIES OF TRAINING In the definition of SRA, we established that there are 4 different systems that undergo their own SRA sequences with any training. It was also established that if the improvement of one of those systems was prioritized, a theoretical optimal training frequency would best support the development of that system. For example, because muscle Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 208 size accretion tends to last from one to several days after a training session, training that certain muscle group should likely occur every one to several days for best results, and something like multi-a-day training or once per week training would produce worse results than possible. Because multiple systems need to be developed in each training phase/ goal (technique training, hypertrophy, general strength, peaking), lengths of phase-tailored SRA curves are biased heavily in the direction of the main systems that underlie that phase, but some effects on other systems are considered as well to produce the best total outcome. The following is a quick summary of the different training goals and their average/typical SRA curve length ranges, ordered from most to least frequent both between and within goals: Technique Learning, Development, Refinement: Between several overloading sessions per day to 4 or so overloading sessions per week Hypertrophy: Between 4 overloading sessions and 2 overloading sessions per week Basic Strength: Between 3 and 1 overloading sessions per week, with at least 1 light session per week if down to 1 overloading sessions to conserve hypertrophy and technique Peaking: Between 2 and 1 overloading sessions per week, with at least 1 light session to conserve hypertrophy and technique Connective Tissue Strengthening: A break from training past 80% 1RM for at least a month every 4 months or so Many readers of this book, especially ones that are very detail minded, might wonder why such broad ranges are described. In effect, why can’t frequency recommendations appear as points on a timeline rather than Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 209 wide ranges? For example, why can’t the hypertrophy recommendation be “train exactly two days apart when trying to put on size” rather than the lacking “train between 2 and 4 times per week?” On the other hand, the opposite question is also valid. Why are the recommendations so delimiting? Can’t other program variables be structured in some way as to produce best results with most any frequency shorter than about a week? For example, if you train a muscle REALLY hard, shouldn’t its SRA curve now be longer and thus accommodate less frequent training? In order to address those concerns, we will split the discussion into two; firstly concerning ourselves with sources for variance of frequency recommendations and secondly with constraints on the variance of frequencies. Discussions about these differences could be article-length in their own right, so we’ll only seek to supply the basic information here to keep the discussion to a reasonable length! S O U R C E S O F VA R I A N C E S E S S I O N -VO LU M E VA R I A N C E If a training session is overloading in intensity but low on volume, the SRA curves generated are shorter, but still elicit a net adaptive peak. With low volumes, the height of this peak will be shorter, but the length of the SRA curve will be concomitantly shorter as well. What this means is that training can occur more frequently if the per-session volume is lower. Suppose we usually did 8 sets of squats every 4 days. If we were to do 4 sets of squats every two days instead, we would only get about half of the adaptive peak with each of those workouts, but we’d be able to do double the workouts than before in the same 4 day span, so that the Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 210 net adaptation yield is essentially the same. On the other hand, if we normally do 4 sets of squats every two days but for some reason our schedule changes and now we can only train squats every 4 days, we can simply do 8 sets every 4 days and receive a very comparable net adaptive yeild. Please see the graphs below. F i g u re 1 9 : S i m i l a r R e s u l t s T h ro u g h D i f f e re n t S R A A r ra n g e m e n t s Can we extrapolate infinitely in both directions and still equalize net adaptation? If we squat one set per day or only squat with 16 sets every 8 days, are the results still the same? Probably not, and we’ll examine Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 211 that idea in depth in the next section on constraints to frequency variation. But for this section, the big message is that within some rather broad timelines, there is a good bit of leeway on effective training frequencies by simply spreading out or clustering the workload, so long as the total work is still the same. TECHNICAL PROFICIENCY DIFFERENCES Lifters that are new to powerlifting do not yet demonstrate a mastery of the technical execution of the lifts. In fact, not only do they demonstrate a lack of mastery, they in fact have a very high lack of technical stability. For example, their squat can look noticeably different with every session, their bench press can touch on wildly different parts of their chest, or their deadlift setup changes in breathing patterns every other workout. Especially when beginning powerlifting training, it’s very important to establish a good technical base that will help the lifter: a.) Develop effective technique that puts their body in the right position to lift the most weight possible. You can get away with crappy technique with beginner weights, but you’re not going to good-morning 585 when you’re supposed to be squatting it. Techniques are very hard to change once they are well- established in the early phases of training. This is a good and bad thing, because while it means that good coaching early on can set up an excellent technique for a lifetime, a lack of technical practice or poor technique early on can cost the lifter for years down the road. b.) Develop a safe technique that will prevent the lifter from getting hurt needlessly later in their development when their weights in training and competition begin to rise to the kind that can really mess you up! Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 212  c.) Capitalize on early neural strength gains. One of the oldest observations in strength research is that the first several months of strength training sees strength improvements that far outpace muscle size additions. This is because the nervous system is both learning to enhance its force output per individual neuron and groups of neurons as well as coordinate muscle timing better to produce higher forces. Higher training frequencies give the nervous system more practice to improve its abilities and have been shown to result in more rapid improvement in strength levels of beginners. As the lifts are practiced for months and years, the incremental benefits of more and more technical practice begin to decline. Powerlifting is incredibly simple in its technical demands when compared to literally every single other sport, and advanced lifters show a remarkable technical stability even when lifts are not performed for weeks at a time. Of course if the goal is optimal technical prowess, practice of the lifts still needs to be more frequent than once every several weeks, but it becomes difficult to construct an argument for more frequent lifting than about twice a week (for each movement) for advanced lifters. And if the added frequency is not improving technique or accomplishing anything else, the lifter might be better served simply taking the extra days off from training to further promote recovery/adaptation. The implication is that based on lifter development/experience in the sport, different frequencies from the perspective of technical development/retention arise and are placed on a spectrum of most to least frequent. This means that two lifters who would normally train together may not want the identical session frequency if one of the lifters is significantly more experienced than the other. It also means that as a lifter gains experiences and begins to demonstrate technique Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 213 solidification, one of the advantages of super-high frequency programs can become less prominent. FIBER TYPE DIFFERENCES Fiber type is determined mostly by the alpha motor neuron that innervates the muscle fiber. Thus, any discussion of fiber types is also a discussion of PNS physiology. Slower twitch fiber types don’t produce as much force as faster twitch fibers. Slower twitch fibers do not undergo the same level of damage and homeostatic disruption from training, and they heal faster from such damage. They don’t increase their protein synthesis rates (FSR curves) for nearly as long or as high as faster twitch fibers do. For those reasons, slower twitch fibers can and need to be trained more frequently, while faster twitch fibers less frequently. These differences can reflect themselves within the different muscles of the same lifter and between different lifters. Some muscles on average contain a larger fraction of faster twitch fibers than others. The hamstrings, for example, are usually faster twitch than the quads in most lifters. Thus, all else being equal, the hamstrings may benefit from lower training frequencies than the quads. This is well illustrated in the observation that high frequency squatting programs are very successful especially with newer and smaller lifters but that the first proponent of the high frequency deadlift program is probably lying dead in a power rack somewhere as you read this! Differences in fiber type ratios also exist between different lifters. If a certain lifter has a higher predominance of slower-twitch muscle fibers than another, he/she can likely tolerate and benefit from higher frequency training. Lifters with faster average fiber characteristics can instead benefit more from lower frequencies of training. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 214 MUSCLE SIZE & ARCHITECTURE DIFFERENCES Bigger muscles can take on more damage and can take longer to recover and longer to grow after every session of training. This has something to do with their strength, but the sheer size plays a role as the amount of physical tissue to be remodeled is greater, leading the immune system and other systems within the muscle to have to work longer. Bigger muscle fibers (cells) still produce new proteins at a rate limited largely by their nuclei, and the number of nuclei doesn’t change much, especially after all satellite cell donations of nuclei have run their course. This means that if your chest is the size of Ronnie Coleman’s, an overloading session may generate SRA curves similar in length to those of the typical lifter’s quads! This of course also means that smaller muscles usually have faster SRA curves and thus frequency demands than larger muscles. You can get away with training your biceps and rear delts nearly every day with hard, overloading sessions, but trying that with your quads with any decent volume per session will lead to training sore almost all the time, and plenty of adaptive interference that goes along with that. In addition to muscle size, all muscles have different architectures. Their fibers are arranged in different patterns, leading to unipennate, multipennate, fusiform, and other sorts of arrangements. Muscles with certain fiber arrangements have higher proclivities to output force and thus take on damage and homeostatic disruption. Yes, you can hypothetically get your biceps as sore as your pecs, but the volume of training required to do that will bring your biceps into overreaching within several sessions. Because different muscles have different fiber arrangements within the same lifter, certain lifts will benefit from different frequencies of training than others. The best example is Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 215 that most lifters can tolerate upper body pulling work (vertical and horizontal pulling exercises) multiple times per week, often with every training session, but that chest and glute training almost every session is essentially unheard of. Also, different lifters vary in their muscle architecture even in the same muscle, such that one person may have quads that are better suited for high frequencies in their architecture than another. STRENGTH DIFFERENCES Stronger lifters can disrupt homeostasis more profoundly than weaker lifters. That means their SRA curves for hypertrophy, but especially for nervous system strength adaptations and connective tissue strength adaptations are going to be longer. A nearly universal observation on the training of powerlifters is that stronger lifters tend to gravitate naturally towards lower frequencies and vice-versa. P SYC H I C E N E R GY D I F F E R E N C E S Lifters that psych up more for their training sessions can generate longer SRA curves than lifters who stay calmer. Because the SRA curves of the psych-up lifters are higher in magnitude as well, the net benefits might be similar between the two groups, but only if lifters that give it more of their “all” in each rep and set reduce their frequency of training. Observation of the sport reveals that both approaches seem to work well, but only if they are frequency-adjusted to their needs. If you’re getting pumped for a lot of training, you likely need more time to recover and adapt between sessions. If you’re calm and cool, you should probably train more often to take advantage of your faster SRA curves. On the extremes, training with minimal arousal infrequently has not produced many champions, and training with maximal arousal frequently Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 216 has produced many early retirees from lifting due to poor results, overtraining, injury, and psychological burnout. L I F T- S P E C I F I C D I F F E R E N C E S Because different lifts activate different amounts of muscle, because they produce more or less force, because they tend to be associated with different levels of psychological arousal, and because they tend to require more or less nervous system activity and damage more or less tissue, they tend to have different average SRA curve lengths. The SRA curve of a lift is the amount of time it takes for performance in that lift to adapt to its maximum. Now, only in peaking and over the course of a deload are we ever going to allow full recovery between lifts, but because some lifts take much longer to go through their SRA cycles than others, they tend to overreach faster and risk dipping into net-neutral overtraining within the mesocycle, as opposed to other lifts than can experience a beneficial overreaching effect within that same time. There are still other lifts that have such short SRA curves that training them only as frequently as the average lift may entirely pass their adaptive peak and lead to suboptimal adaptive summation and thus unimpressive improvements in the long run. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 217 F i g u re 2 0 : S R A C u r ve E x a m p l e s o f S q u a t t i n g , B e n c h i n g , D e a d l i f t i n g , L a rg e a n d S m a l l Ac c e s s o r y Wo r k Here is a quick guide to SRA curves for different common powerlifting movements, both competition and accessory: Small Muscle Lifts/Upper Back Lifts: Muscles such as the biceps, rear and medial delts, lats, and other smaller muscles of the upper back typically recover very quickly from overloading sessions, allowing many lifters to train them up to four times per week, and in some cases even more often than that. Squat: Squats are heavy enough to be very taxing, but the slower-twitch characteristics of the quads tend to mitigate that somewhat. Especially Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 218 for smaller and less strong lifters, squatting daily for short periods of time can be sustainable, and even the bigger and stronger lifters report some kind of lower body quad-heavy work at least twice a week, with only once a week of any kind of quad stimulus being quite rare. Bench: Likely due to the fan-shaped structure of the pecs and the multipennate structure of the triceps, as well as the usually faster- twitch characteristics of these muscles, bench pressing does not usually lend itself to the same frequency as squatting. While squat every day programs have been popular with beginner lifters and continue to be a perennial feature of the powerlifting training scene, “bench every day” programs remain considerably absent. Smaller and less strong lifters can benefit from overload benching up to 4x a week, but stronger lifters rarely overload the bench more than once per week, and as previously stated, current world record holder (at the time of this writing) Kiril Sarychev only overloads the bench every week and half or so, just to illustrate the extreme. Of course the muscles of the bench can be trained more often, with most doing at least 2x a week, but that second session tends not to be as overloading and usually avoids overloading the bench press itself again, with assistance lifts usually being overloaded instead. Deadlift/OHP/Hamstring Work: The hamstrings tend to be faster twitch and can produce high forces relative to their size, so typically experience long SRA curves. Deadlifts and overhead presses face similar problems, but also demand very high psychological arousal and engage a vast quantity of muscle. Deadlifts engage something like 80% of the skeletal muscles of the body, and standing overhead pressing requires almost every single muscle below the shoulder to act in a stabilizing fashion, especially during very overloading and relatively intense sets. This leads to the conviction by many lifters that heavy deadlifts (overloading Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 219 intensities and volumes) can only be programmed once a week for most lifters, with similar thoughts on standing overhead pressing. In fact, many of the biggest and strongest deadlifters in the world only pull overloads as infrequently as every two weeks! T R A I N I N G - M E D I AT E D C H A N G E S Body systems have a high (though not limitless) degree of adaptability. This means that training at a certain frequency can slightly improve a lifter ’s ability to benefit from that frequency. This works especially for the high-frequency end, as chronic training in higher frequencies usually makes them more tolerable and beneficial as recovery mechanisms adapt to work faster. This likely has mostly to do with fiber type alterations but may include other mechanisms and is worthy of its own mention. C O N S T R A I N T S O N VA R I A N C E There are three main constraints on the potential variance of training frequencies that produce best results; the “insufficient overload problem” in the high frequency direction and the “excessive fatigue/ overload ratio problem” and the “adaptive dissipation problem” in the low frequency direction. I N S U F F I C I E N T OV E R LOA D P R O B L E M Human physiology evolved mostly in a very calorically restricted (or at least pulsatile) environment. Our hunter-gatherer ancestors went for long periods without much food, and thus developed a host of mechanisms to conserve energy use when such use has not demonstrated to be worthwhile for survival and replication. One such adaptation is the Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 220 very physiology that governs the overload principle itself. The systems that govern strength development need an overloading condition in order to adapt and improve their function, which is a metabolically expensive process. The muscles and nervous system don’t just change their performance and structure with any stimulus. A stimulus must meet the overload condition in order to elicit adaptive responses, which means there must be a minimal range of both intensities and volumes for adaptation to occur. This range of intensities and volumes definitely defines what is overloading and what is not in a single week. If you lift heavy enough (intensity) and do enough heavy lifting (volume) during a week, then you’ll likely be getting stronger than last week. Same of course goes for the month and the year, but does it go the other way for shorter slices of time? Probably. In any one training session, there is likely a minimum volume and intensity needed to overload and disrupt homeostasis enough to activate adaptive pathways. If a session does not meet that minimum and falls far short, the amount of adaptations may fall below the ratio of volume it took to get there. Even if you do 10x that many sessions, it may be the case that the sum total adaptive magnitude from 10x that many sessions is not as high as if you had done 10x the work in one session. There is a likely a small but meaningful effect of the disruption of homeostasis in one session all at once that triggers adaptation, something that multiple smaller sessions cannot replicate. A quick analogy can be constructed as the following. Imagine you had a piece of paper and gave a friend a bunch of scotch tape. Your goal is to get the whole piece of paper covered with tape (adaptations), and your tool was a pencil (training overload). Your friend is only allowed to tape up holes poked in the paper. He cannot simply tape the paper Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 221 if it has not been ripped. So being the evil genius that you are, you poke moderately sized holes in the paper and let the friend tape over each one... soon tape covers the whole paper and you’re met your goal! But what if your pokes were not sufficiently hard to cause any tears whatever? How much tape would be put down? None, it seems. The above analogy exaggerates the point... some adaptation would still occur even if you just tapped the pencil against the paper, the analogical equivalent of going into the gym and doing 1 rep of squats every several hours. However, there does seem to be good reason to think that the magnitude of the disruption is meaningfully related to the level of adaptation in a nonlinear matter. Below some intensity and “within- session volume,” physiological changes are not made nearly as much in proportion to the work done and for more advanced lifters may not be enough to make any positive changes at all. In common terms, if you don’t challenge the physiology enough at any one time, the signal to make adaptation is simply not as strong as it would otherwise be if a sufficient overload was presented. Even squatting to a max single once a day likely becomes an insufficient overload for more advanced lifters. Yes, a 1RM has a very high intensity, but one single heavy rep causes almost no physiological disruption to a sufficiently well-trained lifter’s physiology. Muscle microtears are almost non-existent, neural perturbations are hardly caused, and the molecular detectors of force transduction in the muscle may not have summed enough activity to even convey the minimal necessary message for any cellular changes to occur. The insufficient overload problem bounds our higher frequency possibilities to some extent. If you train so often that your per-session Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 222 volume must be tiny for MRV to be matched and excessive fatigue to be avoided, you might simply not be getting the best ratio of work to adaptation, as your SRA curves barely blip down because of the stimulus and thus barely blip up to make an adaptation. This is not a concern for most programs as super high frequencies are rare, but it must be noted on a theoretical level so as to prevent possible errors in programming down the line. The “squat everyday” approach may be an example of such a program if applied to very advanced lifters. Such lifters would have to do so little daily work (perhaps only a relative “for that day” 1RM at most) that their very advanced and already adapted (and thus recalcitrant) physiology may simply not reach the overload conditions needed for best adaptations. Splitting their weekly training into fewer but more individually overloading sessions may be a better approach. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 223 E XC E S S I V E FAT I G U E /OV E R LOA D R AT I O P R O B L E M From the paper and tape analogy in the last section, what would happen if you used the pencil to tear the paper into tiny bits that could barely be located to tape up? The very damage that is supposed to be part of stimulating the adaptations becomes too excessive and itself interferes with the adaptive process. You’d spend more time picking up the pieces than you would doing the taping, even if we assume you’d be able to re- arrange the pieces back into a single sheet. If a lifter would endeavor to train with excessively low frequency (let’s say once every 2 weeks for the average lifter), the amount of volume that would need to be presented in that one session to come close to MRV would be astronomical. So astronomical, in fact, that adaptive processes may mostly or entirely take a backseat to recovery processes. The end result after the SRA curve has run its course is perhaps a much smaller magnitude of gain than expected or a mere re-establishment of past performance with no net gain. In plain terms, training very infrequently would have to be so hard that the body may not even be able to adapt to it, but would instead struggle to barely recover. Car accidents can make people’s necks sore for weeks on end due to the profound forces of the wreck, but not many people use car wrecks as a hypertrophic tool. Weak as that analogy is, it does make some point, which was better made by many lifters of generations past with the adage; “stimulate, don’t annihilate.” What are some practical timeframes in which overloading too much causes mostly fatigue and no stimulus? This depends highly on the lifter in question and their particular situation, but some basic guidelines can be drawn. Technical abilities likely need at least two sessions of technique work per week to improve performance (which includes overload sessions themselves, not just technique-only sessions). Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 224 Advanced lifters who already have stable technique can get away with less (ala Westside), but technical improvement is still not what is being sought, even in that case. For hypertrophic adaptations, beginners likely need at least weekly stimulation of the same musculature, but even that becomes inadequate within several months and is only good enough for maintaining size from that point on. The per-session volume loads required to still make best gains on only 1x per week training per muscle group are too much for all but the most muscular individuals, and training in such a manner is not likely to be the best approach for most. Interestingly, the bodybuilding routines of the pros seen in magazines and copied by beginners across the world on a daily basis often include once-weekly programming for the larger muscles (chest, back, legs). This might actually be appropriate for bodybuilders of pro size due to their muscularity and the longer SRA curves they can generate. Unfortunately, this once-weekly training strategy only works well if you’re over 250lbs of mostly muscle, and the majority of muscle magazine readers who copy these routines do not fit that profile. Neural force output adaptations probably require training at least every 1.5 weeks for most individuals, which is not commonly violated in powerlifting. We have to remember though that if you only train often enough to properly adapt that system, you’re missing out on hypertrophic and technical adaptations that can yield manifold greater improvements. Connective tissue disruption curves are very lengthy, but require constant levels of sub-maximal stimulation over long periods of time to adapt. One reason for this is that the risks of infrequent and very tough single-sessions for connective tissue training are just too great. You’d need such high forces and so many stimuli of them at once that acute connective tissue integrity (example: tendon strength) would be greatly risked and severe injury could result. For this reason, Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 225 the connective tissue adaptation system is probably the worst one with which to try ultra-infrequent training. F i g u re 2 1 : S R A w i t h U l t ra - L ow F re q u e n c y Tra i n i n g A DA P T I V E D I S S I PAT I O N P R O B L E M The second constraint on lower frequency training is the problem of adaptive dissipation. If you take a look at the graph of an SRA curve, you’ll notice that once the adaptive peak has been reached, adaptations don’t stay elevated there forever. If the next training session for that system does not occur at the adaptive peak but rather occurs later, not as much of the adaptation will be conserved. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 226 F i g u re 2 2 : Ad a p t i ve D i s s i p a t i o n B e t we e n S R A C u r ve s If a long enough time lag exists between the first and second SRA curves, the entire adaptive gain could have deteriorated and no net gains are realized from that first SRA cycle. Worse still, if a really long time passes between the two sequential sessions, adaptation could fall below the original state before training occurs, which is termed ‘Involution.” Involution is a particularly undesirable effect because the next session’s adaptive gains have to start in a deficit, and will be hampered no matter what. An easy example of this occurrence can be drawn from muscle growth. Muscles begin to grow within several hours of the last training session, and they can continue to grow for 2 to 4 days afterwards. But if you train a week apart, after the fifth day or so, muscle size starts to decline from its highest adaptive peak reached after the last session. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 227 After the 6th day, some of the muscle from that first session has already been lost. If we train on the 7th day, we’re only saving some of the muscle we built last time, and training any later might get us starting back from baseline or worse. We know from the excessive fatigue/overload problem that SRA curves can only be stretched out so far via larger and larger single-session stimuli before they yield very little or no adaptive magnitude and essentially just become recovery curves. So if we stick to single-session stimuli that are small enough to avoid this problem, we also need to train frequently enough to avoid the second problem of adaptive dissipation. Both constraints act together to reign in the possibility of maximally productive ultra-low frequency routines. R E S U LT: M A N Y F R E Q U E N C I E S P O S S I B L E The above constraints on frequencies do indeed create upper and lower boundaries for potential program design. But these boundaries leave a very wide margin for potentially productive frequencies of training. When we take into account the different contributors to the variation in frequencies such as lifter strength, muscle size and level of technical proficiency, we are lead to the conclusion that many frequencies are possible and can be optimal at different times and for different lifters. If weekly volumes and intensities are being met at close to MRV, the frequency of a program is not a gigantic determinant of success, and in fact a variety of frequencies can be productive. More specifically, any one individual at a certain point in their development in the sport can have a narrower optimal frequency range depending on their goals, but there is not much sense in saying that one type of frequency range is Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 228 just plain better than another type so long as both are within the three constraints mentioned above and workloads and intensities are equated. In the debate between Westside’s low frequency proponents and “Squat Everyday” proponents, the correct approach is dependent on the situation of the lifter, and neither is categorically better or worse. 2. ) A R R A N G E M E N T O F T R A I N I N G D AY S Technically speaking, the training frequency of a program is only the number of days within a certain time period (let’s say a week, but it doesn’t have to be) that training occurs. There is another important variable derived from the structure of SRA curves that must be discussed as well, which is the arrangement of training days within a certain time period. Arrangement of training days describes how the days are actually clustered within a certain time period. For example, if you train the lower body three times a week, this can mean several things: Training on Monday, Wednesday, Friday Training on Monday, Friday, Saturday Training on Monday, Tuesday, Wednesday Etc... The above examples present very different approaches to structuring training, but the training frequency (as measured by week) for all of Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 229 them is identical. However, the results of those training approaches are not identical. The first approach seems logical. An SRA curve is generated and has sufficient time to produce adaptation before the next training session is performed to sum adaptations further. The second approach is fairly spread out, but two problems can be noted; first, there is seemingly way too much lag time between Monday and Friday, and perhaps not enough recovery time between Friday-Saturday. The good news is that we can still get great results if we make Monday a very hard session with a longer SRA curve and make Friday a very easy session with a very short SRA curve, or simply keep all of the days the same in difficulty and let functional overreaching take care of the asymmetries. But even functional overreaching has limits. If we look at the last training arrangement above, we will have a very tough time getting the most out of that sequence. If we train with an even difficulty in each session, our Wednesday session will have a very hard time meeting overload requirements because of the two consecutive fatiguing sessions that precede it. And because of the massive lag time between Wednesday and the next Monday session, we’re sure to start pushing up on the low frequency boundaries of optimal technical and hypertrophic frequencies. The recommendation we can thus derive here is that once we’ve decided on a training frequency, structuring our workouts in a manner that roughly spaces them out in an even manner is probably the best idea. In reality, most everyone discovers this within a few months or years of training, even if it’s the hard way. If you have heavy squats on Monday, heavy front squats on Tuesday, and heavy deadlifts and leg presses on Wednesday, you’ll quickly figure out that your “heavy” deadlifts are anything but, and that the only good workout you have all week is the squat workout. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 230 U N D E R - A P P L I C AT I O N O F S R A Under-application of the SRA principle is when a lifter designs or executes a program without being aware of (or aware enough) of the SRA principle. There are at least three notable examples of this sort of error. 1. ) T O O H I G H O F A F R E Q U E N C Y F O R T H E S I T U AT I O N High frequencies of training and especially of overload training are best for the development and solidification of technique and the stimulating of hypertrophy. When these are the preeminent goals, very high frequency programs are incredibly effective. Mostly, such goals and thus programs are best suited for beginner and intermediate lifters due to their need for technical work and hypertrophy. Smaller lifters and slower twitch lifters are also candidates for high frequency programs even if they are quite experienced and don’t intend on putting on much more muscle. So far so good, but the problem arises when high frequency programming is applied to all lifters across all levels of development, fiber type, strength, and size differences. The number of superheavyweight lifters that train very frequently is incredibly small, as is the number of very advanced lifters. These groups of people generate much longer SRA curves from their greater overload needs and thus need more time to recover, as well as training to focus much more on neural force production abilities than on muscle size or technique. High frequency advocates maintain that powerlifting is a sport, and you must practice the skills of the sport often in order to improve, much like any other sport. The next conclusion is that squatting, benching, and Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 231 deadlifting must be done often so as to maximize technical adaptations. This is true as far as it goes, but for more advanced lifters, it doesn’t go far enough. The powerlifting moves are some of the most simple of all formal human movements, and technical near-mastery is possible within months of time with good coaching. After mastery has occurred, the techniques need to be practiced, but only at a maintenance level (1- 2x per week). The kicker; practicing them more often than that simply doesn’t yield the kind of benefits it does for beginners, and more recovery/adaptation by rest or light training may be of greater benefit for advanced lifters with stable technique. Much the same issue presents itself in the realm of hypertrophy. Once a lifter has reached his or her weightclass limit, the role of hypertrophy training is highly diminished until they choose to move up a weightclass. If a lean 198lb lifter trains mostly for hypertrophy by overloading frequently, this fatigues them too much to get optimal neural force output adaptations, but what good does it do them? They’re going to have to lower their calories in order to avoid having to go up to the next class, and not much else will happen. As good as hypertrophy training is, it’s mostly useful if you’re moving up in weight or saving muscle while burning fat. If you’re at the top of your class already, size training is often just going to be interfering with strength training you could have been doing. For example, the guys at Westside are incredibly muscular, so for them, the impetus to train frequently enough to gain maximal muscle is simply not as great as it is for other lifters. When choosing a program frequency, don’t choose the highest frequency possibly simply because there have been reports of good results by other lifters. It always pays to consider the multiple variables that affect potential optimal frequencies for each individual lifter. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 232 2. ) T O O L O W O F A F R E Q U E N C Y F O R T H E S I T U AT I O N While ultra-high frequency training routines are a relatively newly popular approach, most of the late 90’s and early to mid-2000’s were the time of the low frequency routines, and some of these programs are still in wide use. For many lifters, including the ones that popularized the programs, lower training frequencies are indeed a very effective approach. But not all of the lifters using these programs are training often enough, and some could benefit from more frequent training. This violation is the mirror image of the previous (#1 above) violation. In the 90’s and 2000’s, Westside was king, and everyone and their grandmother was trying out a Westside-inspired split, just like some Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 233 circles today are treating “Squat Everyday” as a holy grail. The result was that lots of experienced lifters were getting great results, but beginners were not doing as well as they could. By only training a muscle group heavy once a week, the technical practice in such routines was very low, and not ironically, some pretty atrocious technique from beginners was rampant (not nearly like the high frequency beginners today, whose technique is actually not bad). The 19 year old in a canvas suit doing something like a good morning at a meet became a comedic commonplace during this time. In addition, the same 19 year old seemed to gain very little size from meet to meet, so his performance did not improve at nearly the expected rate. While his older training partners benefitted greatly from the neural improvements of the program, they had the technical and muscle size base on which to lean on... a base he didn’t yet have and wasn’t on his way to establishing at any fast rate. The way to avoid both this and the opposite error (training too frequently if you’re too advanced or strong or for other reasons) is to program frequencies with the state and needs of the lifter in mind. If that means that the whole training crew might not be able to train on the exact same program all the time, that’s a tradeoff that might have to be made if best results for each lifter are the goal. 3. ) T R A I N I N G T H AT I S T O O C L U S T E R E D This violation has already been fairly well illustrated in the discussion of the arrangement of training days within a certain frequency. Here, we can break down the discussion into a slightly more precise series of points. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 234 Overload training too soon after the last session can have the following negative effects: Interferes with the ability to provide an overload in the present session, as the fatigue from the last session is still quite high. Leaves a long gap between the present session and the next overloading session, during which involution is more likely to occur. Directly blunts current adaptations in progress, limiting the adaptive magnitude of the previous session. Overload training too late after the last session and very close to the next session after can have the following negative effects: Presents fatigue that will interfere with overload presentation in the next session. So there is both a reason to keep sessions far apart both before and after one another, creating the need to spread sessions out within the specified frequency. This recommendation applies not only for each muscle group, but for taxing sessions in general. Placing too many taxing sessions back to back may create high levels of disruption to central systems such as the brain and spinal cord, which can lead to adaptive interference and performance interference even between different body parts. Training heavy squat, bench, and deadlift on 3 consecutive days is thus mostly unheard of, as all of the days interfere with each other and more even spacing within the week is almost certainly better. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 235 O V E R - A P P L I C AT I O N O F S R A Over-application of the SRA principle occurs when a lifter has over- interpreted the SRA principle to be more valuable and impactful to the training process than it really is. This creates an obsessive tendency to attempt to create “perfect” training structures and presents itself in at least three notable ways. 1. ) WA I T I N G F O R C O M P L E T E H E A L I N G T O T R A I N A G A I N We have to wait for the particular SRA curve of the adaptation we are focusing on to reach its adaptive peak and fully recover before training. Muscle growth must just have come to an end before we train for muscle growth again. This does not mean we have to wait for all of the SRA curves generated by each training session to complete before we can train again. If we wait for the nervous system force production SRA curve to finish its course each time, our technique and hypertrophy adaptations would have involuted long ago! And if we waited for connective tissue curves to heal also, we’d be waiting for weeks before training again! When we train for some abilities, we are ok with the accumulating fatigue of other abilities so long as we manage fatigue on occasion and don’t let it get too high. Waiting for full recovery of all systems before training them again would waste an absurd amount of time and potential improvement. This means that if your program variables are arranged correctly and your goal is a technical emphasis, it’s ok to train sore sometimes. If your goal is a hypertrophic emphasis, it’s ok to not train at your strongest. If your goal is strength training it’s ok to have sore joints for some periods of time. So long as you manage fatigue and periodically Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 236 bring down the fatigue in all systems, it’s absolutely fine and in fact necessary for training to occur without full healing of all systems. 2. ) N O T TA K I N G A D VA N TA G E O F F U N C T I O N A L O V E R R E A C H I N G By clustering overloading training sessions close together, we can get the effect of depressing SRA curves much lower than they would normally drop. If the overreaching is within the body’s total ability to recover and adapt over time, the adaptive rebound back from overreaching can be massive, and at various points a very useful tool in training, especially before deloads and tapering periods before a peak for a meet. F i g u re 2 3 : O ve r re a c h i n g Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 237 While most training should not take advantage of overreaching as much as it takes advantage of timely recovery, functional overreaching is very useful in some circumstances, and is more useful in those circumstances than if we avoided it on principle. By extending the time it takes to realize adaptations, overreaching can allow us to recover from overloading training while training very easily to drop fatigue. At the end of this process (to be covered extensively in the chapter on phase potentiation), we have both recovered AND supercompensated at the same time, thus allowing either the expression of best performance at the end of that period or the use of the lighter period for the generation of adaptations and not just to drop fatigue. An inappropriate time to overreach would be before a lot of overloading training has yet to be done. The early overreach interferes with further training by both dulling adaptations at the cellular level and preventing maximal overload presentation via fatigue. If you overreach in week 1 of a strength mesocycle, you’re going to run into serious problems. But if you’re averse to overreaching at any point, you’ll lose too much fitness during deloads and tapers, and thus see worse performances. Overreaching can be a tough approach for those lifters that are usually used to training while feeling at least mostly recovered. Overreaching hurts, requires crazy volumes, and leaves you feeling no good for anything let alone heavy lifting! But properly employed functional overreaching can yield impressive short-term benefits to performance, which are especially useful right before competitions. A religious attitude against overreaching simply due to its unpleasant training requirements and side effects is unlikely to yield the best results. Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 238 F i g u re 24 : Ad a p t i ve D e c a y D u r i n g a P o o r Ta p e r D e s i g n 3. ) S E E K I N G A N O V E R LY S Y M M E T R I C A L T R A I N I N G W E E K Overloading training produces fatigue, and within the microcycle, light sessions and rest days dissipate that fatigue. The most powerful way to use light and rest days is in sequence, so that a lot of fatigue can be brought down at once and not simply re-upped the very next day. In the section on fatigue management, it was mentioned that two consecutive rest days are a good idea for that very reason. You’ll notice that two consecutive rest days actually doesn’t concord with SRA in a perfect fashion. If you want to train with exact symmetry 4 times a week, you should train on Sunday Night, Tuesday Morning, Thursday Night, Saturday Early Morning, or some other split of that nature that never truly gives us a full two days off. While this approach concords well with the SRA principle, it actually violates the Fatigue Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 239 Management principle by not giving a distinct and prolonged time for recovery within each microcycle. In effect, perfect application of SRA violates perfect application of Fatigue Management, but because Fatigue Management is a more important training principle, it usually wins the draw. It seems that the best approach is to get as close to perfect symmetry as possible while still leaving some bias in overload session arrangement to allow for fatigue to dissipate at the best rate. SUMMARY The SRA principle is described in perhaps one of the most technically complex discussions of the book, with no shortage of fancy graphs. But when it comes down to it, it’s one of the simplest principles to define in basic powerlifting terms. At its core, SRA means that you wanna hit it hard in training and then take the time to recover properly before hitting it hard again. Rest too little and your performance and adaptations from each session suffer. Rest too long and the progress you’ve made in past sessions deteriorates too much. Key Points Stimulus recovery adaptation describes the process in which a training stimulus generating a sufficient overload can lead to positive adaptations when sufficient recovery periods are implemented Training frequency will be highly specific to the type of training and the muscle mass involved. Deadlifting for Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 240  heavy sets of 5 reps will result in vastly different frequency requirements than practicing squat technique or doing bicep curls Individual differences also play a role in managing training frequency. Factors such as maximum recoverable volume, technical abilities, fiber typing, absolute muscle size, strength, psychology, and anthropometry all will play a role in how frequently each individual will be able to training SOURCES & FURTHER READING SRA Defined The General Adaptation Syndrome Principles and Practice of Resistance Training Science and Practice of Strength Training Periodization 5th Edition Theory and Methodology of Training SRA Applied to the Development of Fitness Characteristics Sport Nutrition The Influence of Frequency, Intensity, Volume and Mode of Strength Training on Whole Muscle Cross-Sectional Area in Humans Influence of Resistance Training Frequency on Muscular Adaptations in Well-Trained Men Single vs. Multiple Sets of Resistance Exercise For Muscle Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 241  Hypertrophy: A Meta-Analysis The Development, Retention and Decay Rates of Strength and Power in Elite Rugby Union, Rugby League and American Football: A Systematic Review. Applications of the Dose-Response For Muscular Strength Development: A Review of Meta-Analytic Efficacy and Reliability For Designing Training Prescription Adaptive Decay & Reversibility Detraining: Loss of Training-Induced Physiological and Performance Adaptations. Part I: Short Term Insufficient Training Stimulus Detraining: Loss of Training-Induced Physiological and Performance Adaptations. Part II: Long Term Insufficient Training Stimulus Muscular Characteristics of Detraining in Humans Upper-Body Strength and Power Changes During A Football Season The Development, Retention and Decay Rates of Strength and Power in Elite Rugby Union, Rugby League and American Football: A Systematic Review Chapte r N o. 6 Sci en t if ic P r in c ip les o f St ren g t h Tra in in g P 242