You Can’t Measure What You Can’t See: The Efficacy of Visual Feedback by Glen Owen


It isn’t always a question of “what’s next?” but often a question of “what is happening right now?” Strength and conditioning coaches and athletes monitor training loads and intensity to show what training has been completed, and how subsequent training can be changed to affect performance. Similarly, some coaches use products like Heart Rate Variability to measure training ‘readiness’ and fatigue. Although these methods provide information an athlete can use between sessions, they do nothing in terms of providing feedback during training.

The Importance of Quantitative Feedback

Feedback is a necessary component of growth. It is why athletes hire strength coaches and personal trainers: to monitor their progress and give them feedback for growth. This qualitative feedback  is often helpful to help correct and athlete’s exercise form or assist in their recovery. What a strength coach cannot provide is quantitative feedback on an athlete’s performance. A trainer cannot provide numerical information on rep speed, power, or intra-set (between repetitions) fatigue.

The research is there: intra-set quantitative visual feedback can improve an athlete’s training performance between 6-12%(1-3). This feedback gives the athlete the opportunity to work that much closer to their best every training session.

An Example of Quantitative Feedback

If an athlete is performing the clean exercise for power (a velocity driven exercise, meaning you want to clean the weight as fast as possible), the ability for an athlete to track bar speed becomes an immediate feedback tool. Likewise, a strength coach observing this athlete will be able to distinguish if he/her is pushing themselves to be their fastest, or if the athlete is just ‘moving through the paces’. For sport qualities that demand intentional training at near maximal efforts, like power and speed, such feedback is invaluable.


How to Use Quantitative Feedback

Quantitative data will allow an athlete to see a drop off in their speed over a training session. Such data provides an athlete and a coach with the information they need to decide when to call it a day, or keep pushing to go further. If an athlete’s session is geared around maximal speed, the coach and athlete may decide to shut down their training when they see their rep speed has slowed down further than 5%. If an athlete is training for repeat power output, the ability to monitor each individual rep and see the drop off is crucial to determine when a set is beneficial, and when it is detrimental.

This ‘in the moment’ feedback is the future of training monitoring. In conjunction with long term programming and periodization, feedback during sessions will elevate the next generation of elite athletes.

Glen Owen

A Certified Strength and Conditioning Specialist through the National Strength and Conditioning Association, Glen strives to create athletes who are strong in body and mind. He currently trains for weightlifting competitions, and enjoys a variety of recreational sports. Like what you’re reading? Connect with Glen on Twitter and Facebook.


  1. Figoni, SF and Morris, AF. Effects of knowledge of results on reciprocal, isokinetic strength and fatigue. J Orth Sports Phys Ther 6: 190–197, 1984.
  2. Graves, JE and James, RJ. Concurrent augmented feedback and isometric force generation during familiar and unfamiliar muscle movements. Res Q Exerc Sport 61: 75–79, 1990.
  3. Kellis, E and Baltzopoulos, V. Resistive eccentric exercise: Effects of visual feedback on maximum moment of knee extensors and flexors. J Orth Sports Phys Ther 23: 120–124, 1996.