The weight lifting belt’s impact on power output, velocity and range of motion in a squat

Abstract Background: Using a weight lifting belt when performing a variety of resistance exercises is becoming more and more common. The purpose of using a weight lifting belt is its supposed ability to reduce compressive forces on the lumbar spine and enhancement of athletic performance. Although the weight lifting belt has been proven to increase the intra abdominal pressure that helps reduces the shear forces during a squat, little is known about the weight lifting belts effect on the performance. Studies have suggested that wearing a weight lifting belt during a squat can increase the vertical velocity and range of motion. Few studies have focused on the power output, but improvements have been seen while wearing a weight lifting belt when performing a deadlift. Variables such as power, velocity and range of motion are of importance for an athlete when making individual training plans as well as measuring the progress. Therefore more research is needed to identify the actual influence of the weight lifting belt on the performance. Aim: The purpose of this study was to examine if weight lifting belts have an impact on an athletes ability to develop power, velocity or improve range of motion in a squat. Methods: Fifteen healthy men and women familiar with the squat exercise participated in the study. During the study they performed six repetitions of the squat divided into two sets, one set without a weight lifting belt and one with a weight lifting belt. Power and velocity were measured during every squat with a linear encoder and videotapes were made to later calculate the angles in the hip- and knee joints at the lowest position of the exercise. Results: No significant differences were found in power (p = 0.25) or concentric and eccentric velocity (p = 0.61, p = 0.16) with or without a weight lifting belt. Range of motion in the knee joint was greater when not wearing a weight lifting belt (p = 0.03), but no differences in the hip angles were found (p = 0.70). Conclusion: The result from the current study shows that when performing a squat the weight lifting belt has little to no effect on power, velocity or range of motion. Although a noticeable change in range of motion of the knee joint were observed, further studies on larger populations are needed to determine if it is of clinical value.