Two new studies published in Physiology & Behavior provide evidence that athletes can estimate changes in barbell velocity with reasonable accuracy and their accuracy can be improved after a single session that includes feedback. The findings have some important implications for a training method known as velocity-based training, or VBT.
VBT typically uses biometric feedback tools to objectively monitor and prescribe the intensity of resistance exercises, but the researchers were interested in examining whether the tracking devices — which can be expensive and impractical — were necessary.
“Assuming adequate perception of changes in bar velocity, then this approach can be used to guide trainees throughout resistance exercise sessions,” explained study author Israel Halperin, an assistant professor at Tel Aviv University.
“For example, rather than prescribe 3 sets of 10 repetitions, which may be too much or too little for some, we can prescribe 3 sets of in which one completes as many repetitions as required to reach a 10% reduction in bar velocity. The latter is a more personalized approach to training, especially when the end goal is to improve explosive strength, which is important for athletes but also for older adults.”
In the study, 20 college students completed barbell squats and barbell bench presses. All of the participants had at least two years of resistance training experience in performing both exercises. After each repetition, the participants reported perceived changes in bar velocity, which was later compared to actual changes in velocity as measured by a tracking device.
The researchers found that the difference between perceived changes in bar velocity and actual changes in velocity tended to increase with consecutive repetitions. In other words, the estimated changes in barbell velocity tended to become less accurate and less accurate over time — especially for squats.
“The accuracy of changes in bar velocity declined with progressive repetitions. Hence, this approach does not seem to be well suited for sets of higher repetitions,” Halperin told PsyPost.
However, none of the participants had any prior experience with velocity-based training. In a subsequent study, the researchers used a similar methodology, but this time they provided the participants with feedback about the accuracy of their estimates of changes in bar velocity.
“We completed this study wondering: can one’s accuracy estimation improve with training? That is, will providing trainees with information about their accuracy rates allow them to calibrate their ratings, which will subsequently improve their estimations? According to a study that we just completed; the answer is a clear yes. We found that a single session in which trainees received velocity feedback considerably improved their accuracy ratings,” Halperin explained.
“This is an exciting topic that has very little research on. In the near future we are planning to conduct more of such studies to examine practical aspects of this approach.”
The studies were titled: “Perception of changes in bar velocity in resistance training: Accuracy levels within and between exercises” and “Perception of changes in bar velocity as a resistance training monitoring tool for athletes“.
