EXSC216 Resistance Training - Science & Application PDF

2/10/2020 EXSC216 Resistance Training - Science & Application Contemporary Issues Assoc Prof Stuart Cormack 1 Content Part 1: Hormone Hypothesis Part 2: Concurrent training/interference effect Part...

2/10/2020 EXSC216 Resistance Training - Science & Application Contemporary Issues Assoc Prof Stuart Cormack 1 Content Part 1: Hormone Hypothesis Part 2: Concurrent training/interference effect Part 3: Acute & chronic training variables Part 4: Novel & Contemporary Training Approaches 2 3 1  2/10/2020 HORMONE HYPOTHESIS Part 1 4 Hormone Hypothesis Two opposing views 1. Acute post-exercise increases in GH, T, IGF- 1 are necessary to stimulate muscle hypertrophy 2. Hypertrophy can occur in the absence of this hormonal response 5 Hypertrophy Mechanisms 6 2  2/10/2020 Traditional View Increases in GH, T & IGF-1 are a key component of the hypertrophy response Elevations occur in protocols with – Relatively high volume – Limited rest periods – Moderate to high intensity involving large muscle mass (Kraemer & Ratamass; Sports Med 2005) Even if they are not “necessary” they provide optimal environment (Schroeder MSSE 2013) 7 Contemporary Thinking Suggested to be a surprising lack of evidence for the traditional view (West & Phillips; MSSE 2013) Significant gains in strength & hypertrophy in the absence of acute hormonal changes How has this been investigated? 8 Testing Hormone Hypothesis Elbow flexors used as studied muscle group Exposed post-training to either – “basal” hormonal environment or – “high” hormonal environment brought about by lower body training Increases in MPS in “basal” condition despite lack of anabolic hormonal environment “High” condition did not result in greater MPS (West & Phillips MSSE 2013) 9 3  2/10/2020 Additional Arguments Against Women can have substantial MPS in the absence of high post-exercise testosterone “Responders” vs “Non- responders” to hypertrophy training programs not explained by hormonal response Hormonal spike is relatively small compared to normal diurnal variation 10 Hormonal “spike” small compared to normal diurnal variation – intrinsic mechanisms of the muscle likely responsible for hypertrophy rather than acute hormonal environment 11 12 4  2/10/2020 CONCURRENT TRAINING & THE INTERFERENCE EFFECT Part 2 13 Concurrent Training Most sports need some combination of these qualities Training for strength and endurance at the same time is required Does this limit adaptation? 14 Contrasting Modalities Strength Training – Short duration – High/maximal intensities – High force – Anaerobic Endurance Training – Medium to long duration – Low force – Various intensities These modalities elicit contrasting adaptations Does this lead to reduced training adaptations?? 15 5  2/10/2020 General Concept Protein Turnover – Anabolic vs Catabolic State The accretion of muscle proteins is vital for ↑ing CSA Endurance training can lead to a transient ↓ in muscle protein synthesis for several hours Overlapping strength training within this period may be detrimental to hypertrophy – What about strength & power? 16 Camera. et. al.; 2016 17 Potential Mechanisms 18 6  2/10/2020 Mode of endurance training important Power likely more negatively impacted No decrements in aerobic performance * Different to Running concurrent training Wilson et al; JSCR 2012 19 Impact of Endurance Training Frequency STR HYP PWR 20 Impact of Training Duration Baar; Sports Med, 2014 21 7  2/10/2020 22 23 24 8  2/10/2020 No diff between grps for 1RM leg-press increases Both concurrent grps similar increase in VO2peak CMJ perf attenuated when RT before HIIT Concurrent tr is viable to improve strength & aerobic capacity If goal is to improve power then consider order 25 26 27 9  2/10/2020 28 Concurrent Training Recommendations Perform strength & endurance training on separate days if possible or at least separate by as long as possible – Nutritional support HIIT training may have less effect on strength Consider order of training sessions within a day? – Potentially “endurance” training as first session in day Strength can still be developed with concurrent training Unlikely an important limitation unless well trained – Not much choice in many sports 29 30 10  2/10/2020 ACUTE & CHRONIC TRAINING VARIABLES Part 3 31 Periodisation 32 33 11  2/10/2020 34 Taper 35 VOLUME, INTENSITY, FREQUENCY & REST PERIOD 36 12  2/10/2020 VOLUME 37 24 weeks training in trained men (3 yrs experience) – 5, 10, 15 or 20 sets per muscle group per week – 10RM tests on various exercises – Muscle thickness of upper and lower body muscles All groups increased 10RM and muscle thickness – 5 and 10 set groups showed significantly greater increases in 10RM Suggests an inverted “U” curve for dose-response of muscle strength – 5 – 10 sets per week maybe sufficient 38 LWS = < 5 sets per week MWS = 5-9 sets per week HWS = > 10 sets per week 39 13  2/10/2020 INTENSITY 40 Training to Failure Unilateral knee extension – LL reps to failure (~34 reps) – HL reps to failure (~ 12 reps) – LL reps not to failure (~20 reps) – HL reps not to failure (~7 reps) When training with low loads a high level of effort (i.e. to failure) more important than total volume for increasing muscle mass Training to failure with high load does not provide additional benefits 41 Single Set to Failure Performing single set of 6-12 reps – 70-85% 1RM – 2-3 x week – To failure – 8-12 weeks Can increase 1RM in strength trained men – Unclear in women – Unclear in highly trained athletes 42 14  2/10/2020 43 FREQUENCY 44 Dankel et. al.; Sports Med 2017 45 15  2/10/2020 46 47 Morton et. al.; Current Opinion in Physiology; 2019 48 16  2/10/2020 Likely differences between trained and untrained In general – Higher volume (i.e. multiple sets) appears superior – Higher intensity (i.e. closer to failure) appears superior Summary (particularly for hypertrophy when using low loads) – Frequency a little unclear but likely 3 total body sessions seems efficient 49 REST INTERVAL 50 If goal is maximal strength Allow enough rest to maintain intensity Self-selected rest based on perception can work well (auto-regulation) If goal is hypertrophy > 3min rest allows higher volume load with less sets Short rests result in more sets needed to achieve desired volume Both approaches are effective Longo, A. R., Silva-Batista, C., Pedroso, K., de Salles Painelli, V., Lasevicius, T., Schoenfeld, B. J.,... & Teixeira, E. L. (2020). Volume Load Rather Than Resting Interval Influences Muscle Hypertrophy During High-Intensity Resistance Training. The Journal of Strength & Conditioning Research. 51 17  2/10/2020 Grgic, J., Schoenfeld, B. J., Skrepnik, M., Davies, T. B., & Mikulic, P. (2018). Effects of rest interval duration in resistance training on measures of muscular strength: a systematic review. Sports Medicine, 48(1), 137-151. 52 Exercise Order Increases in strength are largest in exercises performed at beginning of session (panel A) For hypertrophy both MJ to SJ and SJ to MJ produce similar results (panel B) 53 54 18  2/10/2020 PART 4 NOVEL & CONTEMPORARY TRAINING APPROACHES 55 Vibration Training Purported as a method of causing acute increases in strength and power Vibration has been used in physiotherapy since at least 1881 Has been used to enhance performance since 1980’s First utilised in Russia 56 What is Vibration Training? Specifically designed platforms Perform dynamic or static exercises – Static squats – Stretches – Dynamic squats As part of warm-up Perform exercises on the platform Vibration parameters – Frequency – typically 0-45 Hz – Amplitude –displacement – Acceleration – determines the magnitude – Duration – typically 30-60 s 57 19  2/10/2020 Types & Mechanisms Whole body vibration Mechanisms – Entire body is on the – Morphological vibration platform Increase load on muscle? Part body vibration Increase CSA? – Focus is on specific limbs – Neural Increase MU firing Different types of frequency & vibration: synchronization? – Hormonal Increased GH & T secretion? 58 Electromyostimulation 61 Electromyostimulation Direct electrical stimulation produces muscle contractions Some evidence of increases in strength in athletes, but not greater than traditional strength training Maybe beneficial as addition to normal strength training to increase workload? May act as a variety in stimulus? Potential use in rehab? Transfer of strength gains from stimulation to sport performance questionable 62 20  2/10/2020 STR.COND.J 33(1); 2011 JSCR 26(9); 2012 63 Hypoxic Resistance Training 64 Two Approaches Local Systemic 65 21  2/10/2020 66 Blood Flow Restriction Resistance Training Low-load strength training with vascular occlusion Alternative to heavy strength training May be beneficial when heavy weight training is contra-indicated e.g. injury How it works: – Perform exercises with limb blood flow occluded – Cuff inflated to ~ 40 - 80% of maximal occlusion pressure A number of studies have found low-load training (20-50% 1RM) with occlusion to deliver similar gains in strength & hypertrophy as heavy load training 67 Occlusion Mechanisms 1. Motor Unit Recruitment – Size principle applies with MU recruitment – Therefore with low-loads Type IIb MU’s may not be recruited – Under fatigue, the recruitment thresholds decrease – High threshold MU’s are recruited with vascular occlusion 2. Hormonal Response – Resistance training results in acute ↑ in anabolic hormones – Occlusion training has shown large ↑ in growth hormone – The role of GH in the hypertrophic response is unclear – ↑ metabolites within the muscles driving an increase in GH and therefore IGF-1 3. Cell Swelling 68 22  2/10/2020 Setup: Cuff widths – Depends on body part – Wider = occlusion occurs at lower pressure – Narrower = occlusion occurs at higher pressure Pressures – Generally 40 – 80% of Arterial Occlusion Pressure Key Component → Measuring/Predicting Arterial Occlusion 69 Systemic Hypoxia 70 71 23  2/10/2020 Safety Risks – Thrombosis (0.055%) – Subcutaneous bleeding (13.1%) – Temporary numbness (1.3%) – Acute pain Not recommended for people with high BP Complete occlusion occurs at ~50mmHg > systolic BP Do not occlude for >10 min 72 OTHER HOT TOPICS 73 74 24  2/10/2020 Functional Movement Screens 75 76 Instability Training 77 25  2/10/2020 Specificity 18 weeks bilateral or unilateral training Maximum squat and step up strength Both groups improved their trained and non- trained exercise Appleby, B. B., Cormack, S. J., & Newton, R. U. (2019). Specificity and transfer of lower-body strength: influence of bilateral or unilateral lower-body resistance training. The Journal of Strength & Conditioning Research, 33(2), 318-326. 78 Transfer 33 trained rugby players 18 weeks training Squat group vs step up group – 1RM squat & step up – 20m sprint – COD test Both groups improved 1RM squat & step up Both groups improved 20m sprint Squat group had larger improved in COD Appleby, B. B., Cormack, S. J., & Newton, R. U. (2020). Unilateral and bilateral lower-body resistance training does not transfer equally to sprint and change of direction performance. The Journal of Strength & Conditioning Research, 34(1), 54-64. 79 Cluster Sets Short rest between each repetition, typically 10-30s in duration Typically used with explosive/power exercises Aim is to maintain bar velocity E.g. 3 x 5/1 30s – 3 sets of 5 reps with 30 s rest between reps E.g. 3 x 10/5 30s – 3 sets of 10 reps with 30s rest after 5 reps 80 26  2/10/2020 TR - 4 x 6 3 min rest between sets C1 - 4 x (6 x 1) 12 s rest between each rep C2 - 4 x (3 x 2) 30s rest between each 2 reps C3 - 4 x (2 x 3) 60s rest between each 3 reps Hansen et al; IJSPP 2011 81 Weakley, J., Mann, B., Banyard, H., McLaren, S., Scott, T., & Garcia-Ramos, A. (2020). Velocity-Based Training: From Theory to Application. Strength & Conditioning Journal. 82 Velocity Based Training Devices 83 27  2/10/2020 How Velocity Can Be Used Weakley, J., Mann, B., Banyard, H., McLaren, S., Scott, T., & Garcia-Ramos, A. (2020). Velocity-Based Training: From Theory to Application. Strength & Conditioning Journal. 84 Velocity-based Strength Assessment Velocity at failure – Stable across different strength levels – Stable after training intervention Pros – Predicts reasonably well from low loads – Quick – Allows frequent (e.g. each session) assessment Cons – Requires technology (although very common) – Different equation for each movement – Some accuracy limitations 85 Recovery After Strength Training 86 28  2/10/2020 ROLE OF STRENGTH IN ATHLETIC PERFORMANCE 87 88 89 29  2/10/2020 https://simplifaster.com/articles/review- strength-training-coordination-integrative- approach/ 90 Impact Of Strength On Fatigue Response CMJ Peak Power CK Johnston RD, Gabbett TJ, Jenkins DG, and Hulin BT. Influence of physical qualities on post-match fatigue in rugby league players. J Sci Med Sport 18: 209-213, 2015. 91 91 Tofari PJ, Kemp JG, Cormack SJ, and Research C. Self-Paced Team-Sport Match Simulation Results in Reductions in Voluntary Activation and Modifications to Biological, Perceptual, and Performance Measures at Halftime and for up to 96 Hours Postmatch. J Str Cond Res 32: 3552-3563, 2018. 92 30  2/10/2020 0.3 Results.1 0 Very high-speed running and -0.1 ΔPotentiated Twitch C o r r e la t io n (r ) -0.3 ሶ 2peak and RPE 𝑉O -.5 IMTP N.kg1 and ΔCreatine Kinase -0.7 -1 M id - P re P os t P os t2 P os t24 P os t48 P os t72 P os t96 Half Post - Pre - P2r eh Post24 - Pre Post48 - Pre Post72 - Pre Post96 - Pre Tofari et. al.; 2018 93 93 94 31