Kinematics and Kinetics of High and Low Velocity Resistance Training Equated by Time Under Tension: Implications for Hypertrophy Training

Abstract

Time under tension (TUT) is thought as an important mechanical stimulus for strength and hypertrophic adaptation. The purpose of this study was to determine if two training loads (35 and 70 % 1RM) equated by TUT, differed in terms of their kinematic and kinetic characteristics. Twelve recreationally trained men were recruited in this acute randomized within-subject cross-over design. The 35 and 70 % 1RM loading schemes were equated by TUT based on the ground reaction forces data of a half squat exercise. TUT, average force, peak force, average power, peak power, total work and total impulse were calculated for the eccentric and concentric phases of the squat. Of the 12 variables that were found to be significantly different between loads, 10 of the variables were greater in the lighter 35 % 1RM loading scheme. The major findings were that significantly (P < 0.05) greater (41.5–59.5 %) total session average and peak power were found for both the eccentric and concentric phases for the 35 % 1RM loading scheme. However, significantly greater (32.3–34.3 %) eccentric and concentric total impulses were found for the heavier loading scheme. It would seem that when equated by TUT, that lighter loading schemes offer similar peak and average forces but superior velocity and power outputs which may have interesting implications for high-velocity hypertrophic adaptation.