Blog By Erin Feser

Matching technical needs and adjusting training volume with wearable resistance

Are you a coach that always finds himself “time poor” when working with athletes?

Having enough time to do everything you want to with your athletes is a challenging reality faced by many coaches, especially those working with student athletes. These constraints likely result from athlete schedules, organization rules, or priority of tactical and technical training. This leaves coaches with the task of deciding how to fit the desired strength and conditioning programming into the allotted time frames.  And, many times, aspects of the programming must be compromised.

When training time constraints occur, it is imperative that you fully optimise your allotted time. How you accomplish this will vary based on the focus of the season. But in general, when time runs short, there are two smart options to optimise time: 1) match the training to the technical demands of the sport as closely as possible; and/or 2) increase the workload of each training session.

A training tool that can be used to accomplish these options is wearable resistance. At SPRINZ, we have been looking into the use of wearable resistance attached to the legs to find ways of improving track and sports speed.  Here we will review the theory behind why wearable resistance is such a useful training tool to achieve both options listed above in the context of training to improve sprinting speed.

Option 1: Match the training to the technical demands of the sport.

A primary advantage of wearable resistance training is the ease in which you can match the resistance training to the specific movements of your athletes’ sport. For example, with sprinting, attaching wearable resistance to the legs and having your athlete go through their sprint specific drills will directly overload the same muscles used during sprint running. Also, since we use light loads with leg wearable resistance (e.g. 200 g per leg), the athlete will be able to move at similar speeds to when they are unloaded. This further matches the specific technical demands of sprinting. When we find ways to closely match training to the technical demands of sport specific movements (such as using leg wearable resistance during sprinting) – we expect strength and metabolic improvements to transfer to the sport specific movements better than training that is less closely matched (for example, a heavy loaded back squat).

Recently researchers found that training with calf wearable resistance transferred to improvements in sprinting for national U20 level soccer players.1 And, even more, the calf wearable resistance training was more effective in reducing sprint times than training with no load. This is interesting because it clearly showcases how well wearable resistance training can transfer to sprint speed – but – it also highlights a method to maximize training time.

These coaches capitalized on warm-up time to influence an important technical ability for their athletes. Typically, we wouldn’t expect what we do in warm-up to necessarily transfer to sport specific skill ability because the components of a warm-up are often general and multi-purpose. But maybe, this study has us re-thinking the integral nature of a warm-up and the possibility of double-dipping on warm-up time as a method to optimise outcomes when time runs short.

Option 2: Increase the workload of each training session.

The addition of wearable resistance to a movement will increase the work needed to perform the movement. In sticking with our example of sprinting, a common prescription is to have the athlete perform sprinting drills with the added load at or near the same movement speed. This has implications on the volume of work performed but, with care, can be used to effectively increase the workload of the training session.

How this works is that the addition of the wearable resistance increases the mechanical, and therefore, muscular work requirements to perform the sprinting drills. When muscular work increases, the metabolic cost of performing the sprinting drills increase. Considering these factors, we can conclude that the simple addition of leg wearable resistance to a sprint running training session will increase the session workload.

We’ve seen the use of wearable resistance to increase session workload in a research study we completed last year Helen Bayne (twitter: @HelenBayneZA) at the University of Pretoria. We worked with a collegiate/semi-professional rugby training squad during a pre-season training block. Half of the athletes wore 1% body mass wearable resistance attached to the legs with calf sleeves (about 400/500 g per leg) during two sprint training sessions a week, while the other half of the athletes completed the same training with no wearable resistance. Unfortunately, over the course of the study attendance was low, averaging 66% across the training squad.  Many athletes had schedule conflicts with evening exams or felt empowered to skip sessions from the low emphasis placed on the strength and conditioning sessions from the head coaching staff. At the end of the training block, maybe not surprisingly, the athletes in the no wearable resistance group had slower sprint times and max speed values. However, the athletes that completed the sprint training with the wearable resistance were found to maintain sprint times and max speed values over the course of the pre-season training block.

The findings from this study suggest that the addition of wearable resistance increased the training session workload to a level that was sufficient to retain sprinting capability when sprinting capability would have otherwise detrained due to an inadequate training frequency. This provides an example of how training volume can be adjusted when training frequency is low by the addition of wearable resistance. An idea for how you can easily bump up strength and conditioning training volume when training schedules conflict or training time priority shifts in the pre-season or in-season to tactical and technical training.2

We suggest you can take advantage of wearable resistance to allow athletes to complete a relatively higher training load in the same amount of time.

This, however, should not come at a compromise to recovery.

You should pay attention to workload changes when preparing wearable resistance training prescriptions and consider using alternative methods to adjust workloads within a training session until you understand how your athletes respond to wearable resistance training. Some options to adjust workloads include reducing sprint distances or alternating between loaded and unloaded repetitions.

In a perfect world, you would have all the time you need to develop your athletes’ sport specific needs. But, as we have all felt in the past, time is a precious resource that must be wisely divided. Fortunately, wearable resistance is one more tool for your coach’s tool belt.




  1. Bustos A, Metral G, Cronin J, Uthoff A, Dolcetti J. Effects of warming up with lower-body wearable resistance on physical performance measures in soccer players over an 8-week training cycle. Journal of Strength and Conditioning Research. 2020.
  2. Feser EH, Bayne H, Loubser I, Bezodis NE, Cronin JB. Wearable resistance sprint running is superior to training with no load for retraining performance in pre-season training for rugby athletes. European Journal of Sport Science. 2020.



Erin Feser ( Doctor of Philosophy candidate. For her Ph.D. research, Erin is focusing on wearable technology and its effect on training for sprint running. “Recent inventions in athlete attire have made it much more comfortable to perform sport-specific movements with resistance on the limbs. With this, we’ve seen a resurgence of using limb loading as a training tool. Our goal with this research is to help coaches understand how athletes will respond to this type of training, which informs how they can capitalize on its benefits in their training programs.

“This research was interesting to me as there are so many possibilities of what questions you can continue asking about limb loading related to performance enhancement and potential injury prevention and rehabilitation applications. I really liked the idea of gaining Ph.D. research experience in this emerging area and, through my supervisor, gaining exposure to what others in this area are researching.”

Erin’s research is supervised by Professor John Cronin from AUT’s School of Sport and Recreation.