Introduction
Velocity based training (VBT) has picked up some pace in the S&C field over the past few years, made somewhat more accessible by advances in technology. The concept certainly isn’t new, but the development of wearable accelerometers e.g PUSH band has made applying the practice much easier. By being able to measure the velocity of the barbell, it helps coaches formulate a load velocity profile for an athlete. This can help inform the decision making process with load prescription, but also provide invaluable feedback on athlete readiness and performance.
Load-Velocity Profiling
Load-velocity profiling is a method which uses a series of repetitions, either with relative or absolute loads, to produce a force-velocity profile for a specific exercise. In order to predict an athlete’s 1 rep max (RM), a coach must first develop a load-velocity profile of an athlete by recording their movement velocities at each load (e.g. 0.8m/s at 60% 1RM. A load-velocity profile allows a coach to easily see how fast an athlete can lift a load at a given percentage of their 1RM (e.g. 60%), helping determine athlete characteristics, and individual strengths and weaknesses. Load-velocity profiling can also highlight areas along the load-velocity curve where an athlete may need some specific training emphasis, information a 1RM test alone will struggle to provide. Once a profile has been established, a coach can then begin to tailor training loads as per cycle emphasis. The force velocity curve (see graph below) shows how the velocity of the bar varies dependent on load.
Usage In The Workplace
1. Testing
When designing a program for an athlete, there are a number of key variables are at the disposal of a coach, namely; intensity, volume, rest period, tempo, frequency etc. Determining intensity has historically been calculated as a percentage of the athlete’s 1RM. An athlete’s 1RM is often determined by testing their maximal strength pre and post a training intervention. This allows the practitioner to identify if the athlete has improved their strength throughout the intervention.
However, using a percentage based training (PBT) approach is often impractical, and therefore, isn’t always a viable option. Here’s why. It takes a considerable amount of time to test a lift maximally. When working with any athlete, timing is precious. There will also be fluctuations in daily 1RM percentages due to training induced fatigue. A PBT approach may expose inaccuracies in load prescription unless it is being tested daily, potentially restricting a coach from getting the most out of an athlete, but also putting the athlete at risk of doing too much.
Although training using exhaustive efforts is common practice in strength training, increasing evidence (Drinkwater et al., 2007) shows that training to repetition failure does not necessarily improve the magnitude of strength gains and that it may even be counterproductive by inducing excessive fatigue, mechanical and metabolic strain for subsequent sessions as well as undesirable transitions to slower fibre types (Fry, 2004).
Fatigue associated with training to failure not only significantly reduces the force that a muscle can generate, but also the nervous system’s ability to voluntarily activate the muscles (Hakkinen, 1993). This could have adverse effects on rapid force production (rate of force development - RFD), movement velocity and power of the vast majority of sports movements (Hakkinen and Kauhanen, 1989). VBT allows predicted 1RM’s to be established by testing sub maximally, helping to avoid excessive fatigue and mechanical stress – valuable in season when training loads can be high.
2. Monitoring
For any athlete, fatigue will always be a pertinent factor. High training volumes and external factors can all contribute towards decrements in performance. There are four generic types of fatigue (Calder, 2013) that apply to any athlete; metabolic fatigue (energy), neural fatigue (peripheral nervous system – ability to produce force / central nervous system - motivation / desire to train), psychological fatigue (emotions, social or work stress factors) and environmental (climate and travel). Symptoms of fatigue are extensive and range from, general tiredness/muscle soreness to poor diet and sleeping patterns - some are easier to monitor than others. The monitoring or control of movement velocity during training complements and refines the concept of ‘level of effort’ (LE) since it truly represents a breakthrough in determining the degree or level of effort during resistance training. The LE not only takes into account the number of performed repetitions per set, but also the maximum number of repetitions that could be completed within the set.
The countermovement jump (CMJ) has been one of the most used tests for monitoring neuromuscular status in individual, and team sports. CMJ performance has been proven to be an objective marker of fatigue and supercompensation (Jimenez-Reyes et al., 2011). Specific CMJ performance factors include the reporting of a number different kinematic and kinetic variables e.g jump height, peak power, peak velocity etc (Taylor et al., 2012). Using VBT as a monitoring tool to determine neuromuscular fatigue can help inform decisions for the ensuing training session. The strength of an athlete, and therefore, readiness can change on a daily basis. Velocity based training allows a coach to adjust the training session/loads to accommodate the readiness of the athlete.
This form of autoregulation can help avoid excessive training induced fatigue and mechanical stress. Autoregulation has previously been defined by as “a form of periodization that adjusts to the individual athlete’s adaptations on a day-to-day or week-to-week basis” [Mann et al., 2010). This method addresses daily fluctuations in strength which are a common occurrence during any intervention. Using velocity to regulate loads gives coaches a true insight into ability on that day. Instead of sticking to a prescribed reps/sets scheme for an entire month or more of training, coaches adjust loads, reps, and sets on a daily basis, dependent on training cycle emphasis and athlete readiness. This form of autoregulation helps target specific areas and decreases the chances of overtraining.
Conclusion
VBT has picked up momentum over the years, providing valuable insight into how an athlete is performing on a given day, not only from a testing perspective, but also a monitoring standpoint. Establishing an athletes load-velocity profile can help identify potential weaknesses and provide a foundation for load prescription. Using VBT as a method for detecting neuromuscular fatigue helps inform decision making, allowing coaches to tailor the session based on their findings. Knowing when to push or pull is an important component of athlete development.
References
Calder, A. “Recovery” Ch.14 in M. Reid, A. Quinn and M. Crespo (eds). Strength and Conditioning for Tennis. International Tennis Federation, Roehampton, London. (2003).
Balsalobre-Fernandez, C, Tejero-Gonzalez. Relationships between Training Load, Salivary Cortisol Responses and Performance during Season Training in Middle and Long Distance Runners. Plos One 2014:9 (8).
Drinkwater E, Lawton T, McKenna M, Lindsell R, Hunt P, Pyne D. Increased number of forced repetitions does not enhance strength development with resistance training. J Strength Cond Res. 2007;21(3):841–7.
Fry A. The role of resistance exercise intensity on muscle fibre adaptations. Sports Med. 2004;34 (10):663–679.
Hakkinen K. Neuromuscular fatigue and recovery in male and female athletes during heavy resistence exercise. Int. J. Sports Med. 1999;14 (2):53–59.
Jimenez-Reyes, P, Gonzalez-BadiloJJ. Monitoring training load through the CMJ in sprint and jump events for optimising performance in athletics. Cult Cienc Deporte 2011;6 (18):207
Mann J, Thyfault J, Ivey P, Sayers S. The effect of auto-regulatory progressive resistance exercise vs. linear periodization on strength improvement in college athletes. Journal of Strength and Conditioning Research. 2010. 24 (7): 1718-23.
Sanborn K, Boros R, Hruby J. Short-term performance effects of weight training with multiple sets not to failure vs. a single set to failure in women. J Strength Cond Res. 2000;14 (3):328–31.
