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Rate Of Velocity Development For Knee Extensors: Crossover To Untrained Speeds

Black, Laurie; Kelly, Stephen B; Brown, Lee E; Coburn, Jared W; Nguyen, Diamond; Dodd, Daniel J; Alvar, Brent A

The Journal of Strength & Conditioning Research: January 2010 - Volume 24 - Issue - p 1
doi: 10.1097/01.JSC.0000367070.92199.20

Rate of velocity development is the measured range of motion traveled from 0 to the target velocity, therefore, a lower value equates to greater limb acceleration. The time it takes to reach max velocity is a critical component to success for athletes. This may contribute to converting the foundation of strength into performance velocity, which is essential in sport performance. The purpose of this study was to examine whether training at a low velocity with single versus multiple set protocols had a differential effect on rate of velocity development in the knee extensors at a faster isokinetic speed. Forty subjects were randomly assigned into one of three groups: control (C; n = 7), single set (SS; n = 14), or multiple sets (MS; n = 19) to perform 8 maximal knee extensions at 60 d/s on an Biodex System 3 isokinetic dynamometer twice a week for eight weeks. The SS group performed one set while the MS group performed three sets. All groups were tested pre, mid (4 weeks), and post tested at 60d/s and 180 d/s. A 3×3×2 (Group × Time × Speed) mixed factor repeated measures ANOVA revealed a Group × Time interaction (p < 0.05). A Tukey post hoc comparison determined that the MS group demonstrated significant (6.36+ 1.66, p = 0.023) decreases in rate of velocity development at 180d/s as compared to the control group at the final testing period (8 weeks). There were no significant group differences at baseline or mid-testing (4 weeks); however, there was a trend toward improvement in both single and multiple set groups from baseline (SS, 6.98 + 1.37; MS, 6.73 + 1.03) to 8 weeks (SS, 6.88 + 1.41; MS, 6.36 + 1.66). The control group showed increases in rate of velocity development from baseline (7.44 + 1.31) to 8 weeks (8.20 + 1.58). There were no significant differences at any time in any group at 60d/s. It was concluded that both single and multiple sets of isokinetic knee extension were superior to the non-trained control condition in non specific velocity training for improving rate of velocity development; however, only multiple set training incurred a significant decrease from the control group. Rate of velocity development is essential in sport performance as the goal of athletes should always be to reach maximal velocity in the shortest amount of time. This study suggests that while both multiple and single set protocols decreased rate of velocity development, multiple set training may be more efficacious for eliciting greater changes in the given training period.

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