Are we getting any stronger? Determining the effect of strength training programs @d_drakey

Reference: Suchomel et al., 2016 Why develop strength? Greater muscular strength is associated with: enhanced movement performance such as jumping, sprinting and change of direction ability enhanced force-time characteristics such as rate of force development or mechanical impulse decreased injury risk factors Reference: Suchomel et al., 2016

As Bill Kraemer said a while back…. A common question asked to strength & conditioning coaches is “what’s your philosophy” when we should be asking “what’s the evidence base for your training program” Reference: Kraemer, 1997

The strength of evidence conundrum We test our athletes to determine their response to the training program The measured change in the test tells us our training effect or evidence for the program The tests we use therefore strongly influences our beliefs, approach and evidence We need to fully examine our testing procedures Reference: Kraska et al., 2009

Testing strength “Determining a maximal strength value for a novice is inherently difficult, because the strength assessment in itself may serve as a strength training stimulus” Jidovtseff et al., 2011

Testing strength Traditionally the one repetition maximum approach has been used However, repetition maximum testing has a number of limitations: Appleby et al., 2012 Buckner et al., 2016 Not time efficient in periods of congested competitions Not appropriate for novice lifters Effected by technical competency / strength training experience Standardizing the vertical displacement and velocity in eccentric phase Loturco et al., 2016 Jidovtseff., 2011 Ploutz-Snyder & Giamis, 2001 McMaster et al., 2014

Isometric multi-joint tests [IMJTs] An alternative to one repetition maximum approach are IMJTs Simple and practical Short test duration Low number of trials required High level of reliability Suitable for male and females Can be used in novice athletes Reference: Drake et al., 2017

Isometric multi-joint tests [IMJTs] Other advantages: Assess symmetry between leg extensor force Determine rate of force development capacities Disadvantages: Requires force measuring equipment Requires a short period of familiarization prior to baseline testing

Isometric multi-joint tests [IMJTs] Test using an Isometric rack Place force plate directly below direction of force application Can be utilized for Isometric squat or Isometric mid-thigh pull tests Adjustable to allow testing at specific angles Photo source: Ulster Rugby

Isometric multi-joint tests [IMJTs] Example force-time trace during maximal isometric squat Peak force Pre tension prior to contraction Source: http://kistler-bioware.software.informer.com

Isometric multi-joint tests [IMJTs] Example force-time trace for left and right legs showing a 7% asymmetry Peak force Left leg Right leg Source: http://kistler-bioware.software.informer.com

Supportive evidence IMJTs have a strong level of evidence supporting their reliability in trained and untrained athletes IMJTs have a strong level of evidence supporting their reliability in male and female athletes IMJTs have a moderate level of evidence supporting their responsiveness to longitudinal strength training programs Full details of the supportive evidence can downloaded from this link: Sports medicine - open Reference: Drake et al., 2017

IMJT procedures Commonly used procedures Up to 5 seconds of maximal effort Take two-three trials Allow 3 to 5 minutes recovery between trials A range of joint angles are used dependent on sport & athlete group, but typically within the range of 90∘ to 145∘ of knee flexion Reference: Drake et al., 2017

Considerations Monitoring change in IMJTs Looking for changes greater than the smallest detectible changes in peak force ~ 10% Choose a testing angle that reflects the range of motion performed within the training program Or an angle that specifically relates to sports performance tasks Ensure repeatability in your methods Dos'Santos et al. (2017)

Contact info Feel free to send me your questions and/or contribute: @d_drakey daviddrake87@gmail.com https://www.researchgate.net/profile/David_Drake Linkedin

References Suchomel TJ, Nimphius S, Stone MH. The importance of muscular strength in athletic performance. Sports Med. 2016;46(10):1419-49. Kraemer WJ. A Series of Studies-The Physiological Basis for Strength Training in American Football: Fact Over Philosophy. The Journal of Strength & Conditioning Research. 1997;11(3). Kraska JM, Ramsey MW, Haff GG, Fethke N, Sands WA, Stone ME, et al. Relationship between strength characteristics and unweighted and weighted vertical jump height. Int J Sports Physiol Perform. 2009;4(4):461-73. Jidovtseff B, Harris NK, Crielaard JM, Cronin JB. Using the load-velocity relationship for 1RM prediction. J Strength Cond Res. 2011;25(1):267-70. Appleby B, Newton RU, Cormie P. Changes in strength over a 2-year period in professional rugby union players. J Strength Cond Res. 2012;26(9):2538-46. Buckner SL, Jessee MB, Mattocks KT, Mouser JG, Counts BR, Dankel SJ, et al. Determining strength: A case for multiple methods of measurement. Sports Med. 2016:1-3.

References Loturco I, Pereira LF, Cal Abad CC, Gil S, Kitamura K, Kobal R, et al. Using bar velocity to predict the maximum dynamic strength in the half-squat exercise. Int J Sports Physiol Perform. 2016;11(5):697-700. Ploutz-Snyder LL, Giamis EL. Orientation and familiarization to 1RM strength testing in old and young women. J Strength Cond Res. 2001;15(4):519-23. McMaster DT, Gill N, Cronin J, McGuigan M. A brief review of strength and ballistic assessment methodologies in sport. Sports Med. 2014;44(5):603-23. Drake D, Kennedy, R.A., Wallace, E.S. The validity and responsiveness of isometric lower body multi-joint tests of muscular strength: a systematic review. Sports Medicine - Open. 2017. Dos'Santos T, Thomas C, Comfort P, McMahon JJ, Jones PA, Oakley NP, Young AL. Between-Session Reliability Of Isometric Mid-Thigh Pull Kinetics And Maximal Power Clean Performance In Male Youth Soccer Players. J Strength Cond Res. Electronic, PAP. 2017.