EFFECT OF ELASTIC BANDS VS. FREE WEIGHTS ON DEADLIFT INTERPEAK TIME BETWEEN GROUND REACTION FORCE, POWER, AND VELOCITY
Authors:Austria Cho, Kyle Davis
- Andrew Galpin, Assistant Professor of Kinesiology, California State University, Fullerton
- Lee Brown, Professor of Kinesiology, California State University, Fullerton
- Jared Coburn, Professor of Kinesiology, California State University, Fullerton
The use of elastic bands during resistance exercise results in a linear increase in force with range of motion. However, this may lead to overload occurring later in the movement. The purpose of this study was to examine the acute effects of elastic bands on interpeak times between peak ground reaction force (GRF), peak power (PP), and peak velocity (PV) during the deadlift exercise. Eight men completed two conditions at 60% one repetition maximum (1RM) in random order including: one variable resistance condition (B) and one traditional free-weight condition (NB). The B condition was performed such that 65% of the total resistance came from traditional free-weights and 35% from elastic bands. All of the resistance during the NB condition came from free-weights. The average resistance was equated for both conditions. The B condition demonstrated significantly (P<0.05) faster time (s) than the NB condition for time to GRF (B-0.033±0.114 and NB-0.386±0.149), for time from GRF to PP (B-0.271±0.088 and NB-0.347±0.103), and for time from GRF to PV (B-0.286±0.084 and NB-0.375±0.096), whereas the time from PP to PV (B-0.015±0.036 and NB-0.027±0.029) was not significantly different. These results suggest that when lifting at relatively low intensities of 60% 1RM with elastic bands, the timing of the peaks of ground reaction force, power and velocity occur later in the range of motion. In a traditional free-weight deadlift, the most difficult portion of the movement is at the initial pull when overcoming the inertia of the weight, while in a deadlift with bands, the most difficult portion of the movement is at the top of lift when the bands are fully stretched. Therefore, muscles may be overloaded at a different point in the length/tension curve by altering the method of resistance.