Variable Resistance Training Increases Power Development
Variable Resistance Training (VRT), sometimes called accommodating resistance, is a type of training that I’ve been interested in for a while now, and which has been a part of the powerlifting community for even longer. VRT is what you’re seeing when a lifter adds elastic bands or chains to the bar before a lift. This has the effect of increasing the resistance toward the end of the concentric phase of the lift.
VRT is a relatively new aspect of training, and as such has not been well studied. The basis of its effects and effectiveness are largely anecdotal. In a recent study in the Journal of Strength and Conditioning, researchers sought to learn more about the effectiveness of VRT and how much resistance works the best.
The proposed reasons to use VRT are numerous. For example, the leverage for most movements is typically greater toward the end of the concentric phase and so more weight can be used. VRT allows extra resistance at the point where you are strongest. Some lifters have sticking points that VRT can also emphasize to help work through them. A bencher with weak triceps will have difficulty as the movement progresses, and VRT can eliminate that weakness.
Perhaps the most important reason to use VRT is to improve the rate of power development. Increasing concentric resistance creates a need to accelerate continuously. The researchers in this study proposed that power development might be a more critical part of lifting success than peak power alone.
In the end, the researchers decided that VRT was an important part of resistance training. It was as effective at developing strength as lifting heavy weights with no elastic bands, but it might be even better at increasing power development.
In the study, the researchers used a band load that represented 30% of each participant’s 1RM, subtracting that same amount from the weight lifted. The design was unique in the fact that it was the middle portion of the lift in which the lifters had identical relative tension, and the VRT group had greater tension at the top of the movement than the control group. The participants, who were NCAA basketball players, added the band workouts once per week to their normal routines.
Researchers did discover that the rate of power development increased more in the group of athletes using bands after five weeks of training. There were also some greater improvements to strength and lean muscle mass for the VRT group, although the total loading was relatively higher.
VRT is one of those things that is both simple and effective. More athletes need to get on board with this method of training, particularly where strength and power are of concern. Which is to say, this applies to pretty much every athlete. Perhaps if you’re a marathon runner you don’t need to make much use of this type of training, but for everyone else, VRT is a bandwagon that needs to be boarded as soon as possible.
1. Jordan M. Joy, et. al., “Elastic Bands as a Component of Periodized Resistance Training,” Journal of Strength and Conditioning, DOI: 10.1519/JSC.0b013e3182986bef
Photo from Chris Duffin's Athlete Journal.