Week 12 - Lecture Nutrition for Resistance Training PDF

Protein Intake & Resistance Training Dr Jonathon Weakley SECTION 1 – RESISTANCE TRAINING AND PROTEIN  Objectives Skeletal muscle adaptations to training Protein function Protein total, timing, type Protein & resistance training Overnight protein...

Protein Intake & Resistance Training Dr Jonathon Weakley SECTION 1 – RESISTANCE TRAINING AND PROTEIN  Objectives Skeletal muscle adaptations to training Protein function Protein total, timing, type Protein & resistance training Overnight protein intake Genetic make up Environment  Skeletal muscle adaptations The size of human muscle is dictated by changes in rates of muscle protein synthesis and muscle protein break down When protein in consumed, there is a significant, but transient, increase in muscle protein synthesis. In the rested, fasted state rates of protein breakdown exceed those of synthesis It is the relative contribution of these fed and fasted periods that dictate muscle mass over time  Skeletal muscle adaptations Resistance training imparts a positive impact on skeletal muscle size Even a single bout of RT in the fasted state can increase MPS… but not enough to promote a positive net protein balance. Instead RT often serves to ‘potentiate’ MPS in response to consuming protein. Training Status : Trained and Untrained  MPS in trained and untrained athletes The effect of training age on muscle protein synthesis is an important consideration. After just 8 weeks of training, there is an attenuation of the duration (but not magnitude) of MPS. Tang et al. (2008)  Trained vs. Untrained – Strength & Endurance Differential skeletal muscle adaptations are induced by RT when compared to endurance training. After just 10 weeks of RT, performing a single bout of RT causes myofibrillar protein synthesis but not mitochondrial. Before training, both showed significant in protein synthesis. Muscle Protein Synthesis Response to Resistance Training Considering that trained athletes have reduced MPS responses, it may be important to place greater focus on the post‐exercise period. A really good review: “A Review of Resistance Training‐Induced Changes in Skeletal Muscle Protein Synthesis and Their Contribution to Hypertrophy” Programming Resistance Training for Muscle Hypertrophy Skeletal muscle adaptations  Resistance Exercise Muscle Hypertrophy Myofibrillar Proteins Muscle contraction, repair, remodeling Time under tension? Volume? Fatigue? Burd et al. (2012) found greater protein synthesis with longer time under tension compared to equal volume matched training. This is likely due to greater muscle activity and the greater motor unit recruitment as greater fatigue was accumulated. Time under tension? Volume? Fatigue? When we standardise the training by fatigue (i.e., training to muscle contractile failure), there is no difference in mixed MPS across a range of loads (e.g., 30% vs. 90%) post and greater MPS at 24 hours. Furthermore, when we standardise fatigue over 10 weeks of training, muscle hypertrophy is ~ equal irrespective of %RM (Burd et al., 2010; Mitchell et al. 2012) Time under tension? Volume? Fatigue? Contractile failure occurs when there is significant muscle fatigue and motor unit activation. It is proposed that the manipulation of a multitude of RT variables mean a lot less for muscular hypertrophy than simply exerting a high level of effort and reaching contractile failure. However, it is plausible that there may be significant strength and muscular endurance benefits when training to failure with different loads. Therefore, when considering muscle hypertrophy not only should volume load and frequency be considered, but so should effort and proximity to contractile failure. Philips et al. 2015 Time under tension? Volume? Fatigue? Philips et al. 2015 Protein Total Type Timing  When people think ‘protein’… ‐ Growth and repair What proteins actually are…  Protein function Regulation Signaling Kinases Insulin Structure Transport Glut 4 Keratin Movement Catalysis PFK Actin & myosin Proteins are made from Amino Acids Non essential AA Essential AA Alanine Isoleucine Arginine Leucine Asparagine Lysine Aspartate Methionine Cysteine Phenylalanine Glutamate Threonine Glutamine Tryptophan Glycine Valine Histidine Proline Serine Tyrosine  Protein storage and turnover Protein Stores: Protein is not considered a primary energy source (1 g protein= 4 kcal) During times of fasting or low energy stores it can be used Proteins in our body are in a continual state of turnover New proteins are being made‐ Protein Synthesis (MPS) Old ones are being broken down to their AA‐ Protein Degradation (MPB) Protein turnover requires energy (20% daily basal energy expenditure) Morton & MacLaren (2012)  Protein digestion for Protein Synthesis Protein digested into polypeptides Individual amino acids Amino acids absorbed into blood and pass into a ‘free’ pool Manufactured into necessary proteins  “You are what you just ate” 12 Healthy Intravenous 20 g intrinsically males isotope tracer labeled casein Arterial blood, femoral artery & venous blood, muscle biopsies for 5h post Results: When ingesting a single dose of protein, 55% of protein derived AA becomes available in the systemic circulation during 5 h post‐ prandial period making these AA available for MPS The other 45% remain in the splanchnic area for gut and liver PS Groen et al. 2015 Protein synthetic response PS Increases for up to 4‐5 h Phillips et al. 2005 Protein synthetic response with RT Increased for up to 24 h + Phillips et al. 2005 Maintenance of muscle mass Protein Net Balance Protein Degradation Synthesis Net Synthesis Net Breakdown SECTION 2 ‐ CONSUMING PROTEIN AROUND TRAINING ‘Total’: Protein Quantity How much is required? Is more better?  Recommended Daily Intake “An RDI is the Type of athlete g/kg BM/day average daily dietary Sedentary 0.8‐1.0 intake level; sufficient to meet the nutrient Endurance requirements of 1.0‐ 2.0 nearly all (97‐98 %) Strength 1.5‐1.7 healthy individuals in Muscle a group” Hypertrophy 2.0 (Burke & Deakin) Protein requirements for athletes Increased synthesis of new proteins Rebuilding and remodeling proteins damaged by exercise Replacement of proteins broken down and oxidised for energy Dose response to protein ingestion + RE Aim: To determine the ingested protein dose response of muscle (MPS) after resistance exercise in young healthy men. Methods: 5 separate sessions 4 x 8‐10 reps to failure Consumed drinks Biopsies 1 h and 4 h containing: 0, 5, 10, 20 or post exercise 40 g of whole‐egg protein Moore et al. (2009)  Mixed muscle MPS is increased in a dose dependent manner up to 20 g 20 g (8.6 g EAA) (0.25 g/kg BM) = MPS maximally stimulated at 20 g What does this tell us? MPS is a saturable process in young people at doses of 20 g high quality protein per serving Moore et al. (2009) Protein Dose Response Relationship More recent work by McNaught et al. (2016) demonstrated that 40g protein may be beneficial when completing intense full body RT. Interestingly, there are not substantial differences in individuals with more or less muscle mass.  How much? To account for differences between individuals, it has been suggested that a dose of 0.4g/kg/meal will help to optimally stimulate MPS. It is unlikely that larger amounts will add any benefit to MPS. However, changes in metabolic feedback regulation, satiety, and thermogenesis may occur! Therefore, when considering how much protein to consume, it is likely that protein beyond the rate at which it can be used for MPS (or other processes) will likely be used in ureagenesis.  Timing of protein Anabolic window? Or Anabolic Barn Door? Timing and distribution of protein ingestion on MPS following RE Aim: To determine how quantity & timing of protein ingestion after a single bout of resistance exercise influences the muscle anabolic response throughout the day in healthy males. Bolus 40 g 40 g Intermediate 20 g 20 g 20 g 20 g Pulse 10 g 10 g 10 g 10 g 10 g 10 g 10 g 10 g 4 x 10 reps at ~80% 1RM 12 h Areta et al. (2013) 20 g whey protein isolate every 3 h = optimal feeding pattern for enhanced MPS Timing of protein Resistance training increases MPS for ~48 hours and MPB for ~24. RT increases sensitivity of muscles to aminoacidemia. Meta‐analysis has shown that consuming protein in closer proximity to RT positively increases hypertrophy. But when controlling for covariates, total protein was the strongest predictor of muscle hypertrophy and timing did not influence outcomes! What happens when we sleep?  Overnight recovery 16 healthy males Single bout of resistance exercise in the evening Recovery drink (20 g protein, 60 g CHO) immediately post exercise 30 min before sleep‐ 40 g casein or PLC Blood samples taken every hour during sleep Biopsies taken before and upon waking up Res et al. (2012) Effectively digested and absorbed Increasing overnight plasma AA availability Stimulated MPS Improved overnight protein balance  Protein timing It appears optimal to ingest protein close to training, but results may not be as drastic as once believed. Moderate doses of protein (e.g., 0.4g/kg/meal) at semi‐regular intervals may provide benefits for MPS and recovery Consuming larger doses of slow releasing proteins (e.g., 40g casein) before bed can augment muscle and strength adaptations. Protein Quality Is it all just the same? Variation in EAA content van Vliet et al. 2015  Protein quality There are differences in the protein you consume. Proteins such as whey and soy are digested rapidly, resulting in rapid aminoacidemia, and induce a larger but more transient rise in MPS.  Whey vs casein vs soy protein Whey has a higher leucine content than casein (20%) – ‘leucine threshold’ Casein is digested slower than whey‐ ‘slow protein’ Whey and soy are rapidly digested‐ ‘fast protein’ Whey: Concentrate: usually contain the fat and lactose Isolate: processed to remove non‐protein components Hydrolysate: processed to change the chemical bonds and promotes absorption  Milk vs soy protein Aim: to determine the long term consequences of milk or soy protein or equivalent energy consumption on training‐induced lean mass accretion in healthy young men males Trained 5 d/wk for 12 wk on a rotating split body resistance exercise program Consumed fat free milk, soy or CHO immediately & 1 hour post exercise Muscle fiber size, max strength, body composition by DEXA measured before and after training Hartman et al. (2007)  Chronic post‐exercise consumption of milk promotes greater hypertrophy than soy or CHO during the early stages of resistance training  Protein quality Whole body protein synthesis is stimulated more with whey despite casein having similar levels of EAA. However, this may be related to the leucine content! When 25g of whey, or 6.25g + 5g of leucine is provided MPS is similar. When isoleucine or valine are provided MPS is not enhanced.  Milk vs. beef ingestion 12 Healthy males 30 g Increased PS post exc from milk & beef Milk ingestion induces greater early myofibrillar protein synthetic response Burd et al. (2015)  Supplementing with BCAA? BCAA are regularly consumed in an attempt to enhance MPS. However, Leucine, Isoleucine, and Valine share the same transporter and result in antagonism for uptake in the gut and muscle and is less effective than leucine supplementation alone!!  Protein Quality To optimize MPS, protein ingestion that contains high leucine content and is rapidly digested is optimal. The difference between protein sources in their ability to stimulate MPS is likely due to a combination of both the delivery (i.e., digestion) and composition. While leucine content is important for MToRc and MPS, it appears there is a threshold for stimulation that is ~3g in young (and potentially higher in elderly). This may help explain why doses of ~0.4g/protein/kg of BM has been shown to maximise MPS. Protein and Carbohydrate Co‐ingestion Is the insulin fairy real?  Carbohydrate and protein post‐resistance training Carbohydrate is often co‐ingested with protein post‐resistance training to ‘stimulate insulin release’ beyond that seen with just protein alone. When insulin is infused into the body at rest, MPS is increased. When insulin is infused along with protein, there is an increase in MPS and slight attenuation of MPB. However, this rise in MPS is not greater than protein alone.  Carbohydrate and protein post‐resistance training However, when adequate protein is consumed (~25g) with CHO following RT, there is no additional enhancements in MPS or reductions in MPB. When training athletes with frequent high‐intensity training sessions, added CHO may be of benefit. Take home messages Yann Le Meur (2015); Morton et al. (2015)  References Areta, J.L., Burke, L.M., Ross, M.L., Camera, D.M., West. W.D. et al. (2013). Timing and distribution of protein ingestion during prolonged recovery from resistance exercise alters myofibrillar protein synthesis. J Physiol, 591.9, 2319‐2331. Burd, N.A., Tang, J.E., Moore, D.R., & Philllips, S.M. (2009). Exercise training and protein metabolism: influences of contraction, protein intake and sex based differences. J of Appl Physiol, 106, 1692‐1701. Groen et et al. 2015. Post‐Prandial Protein Handling: you are what you just ate. PLoS One, 10, (11). Hartman, J.W., Tang, J.E., Wilkinson, S.B., Tarnopolsky, M.A., Lawrence, R.L., Fullerton, A.V., & Phillips, S.M. (2007). Consumption of fat‐free fluid after resistance exercise promotes greater lean mass accretion than does consumption of soy or carbohydrate in young, novice, male weightlifters. Am J Clin Nutri, 86, 373‐81. Institute of Medicine (2005). Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2002/2005) and Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Moore, D.R., Robinson, M.J., Fry, J. L., Tang, J.E., Glover, E.I., Wilkinson, S.B. et al. (2009). Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. Am J of Clinical Nutrition, 89, 161‐168. Morton et al. (2015). Nutritional interventions to augment resistance training induced skeletal muscle hypertrophy. Frontiers in Physiology, 6. Maclaren, D., & Morton, J. (2012). Biochemistry for Sport and Exercise Metabolism. Wiley Blackwell. Phillips et al. (2005). Dietary protein to support anabolism with resistance exercise in young men. J Am College of Nutrition, 24, 134S‐139S. Phillips, S.M. (2014). A brief review of critical processes in exercise‐induced muscular hypertrophy. Sports Med, 44, 71‐77. Phillips, S.M., & Van Loon, L.J.C. (2011). Dietary protein for athletes: from requirements to optimum adaptation. J of Sports Sciences, 29, S29‐S38. Res, P.T., Groen, B., Pennings, B., Beelen, M., Wallis, G.A., Gijsen, A.P et al. (2012). Protein ingestion before sleep improves post exercise overnight recovery. Med Sci, Sport Exc, 44, 1560‐9. Tang, J.E., Moore, D.R., Kujbida, G.W., Tarnopolsky, M.A., & Phillips, S.M. (2009). Ingestion of whey hydrolysate, casein, or soy protein isolate: effects of mixed muscle protein synthesis at rest and following resistance exercise in young men. J Appl Physiol, 107, 987‐992. Van Loon, L.J.C. (2014). Is there a need for protein ingestion during exercise? Sports Med, 44, 105‐111. Van Viliet, S. Burd, N.A., & van Loon, L.J.C. (2015). The skeletal muscle anabolic response to plant‐versus animal‐based protein consumption. J Nutr, 145, 1981‐91.