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Effects of Warm-up on Peak Torque, Rate of Torque Development, and Electromyographic and Mechanomyographic Signals

Altamirano, Kristianna M.; Coburn, Jared W.; Brown, Lee E.; Judelson, Daniel A.

Journal of Strength & Conditioning Research: May 2012 - Volume 26 - Issue 5 - p 1296–1301
doi: 10.1519/JSC.0b013e31822e7a85
Original Research

Abstract: Altamirano, KM, Coburn, JW, Brown, LE, and Judelson, DA. Effects of warm-up on peak torque, rate of torque development, and electromyographic and mechanomyographic signals. J Strength Cond Res 26(5): 1296–1301, 2012—The purpose of this study was to determine if an active warm-up affects peak torque (PT), rate of torque development (RTD), and the electromyographic (EMG) and mechanomyographic (MMG) signals. Twenty-one men (mean age ± SD: 24.0 ± 2.7 years) visited the exercise physiology laboratory on 2 occasions. During the first visit, they either performed an active warm-up (10 minutes of stationary cycling at 70% of predicted maximum heart rate) or sat quietly (no warm-up). Participants were then tested for isometric and isokinetic (60°, 180°, and 300°·s−1) PT, and RTD (measured as S-gradient) on an isokinetic dynamometer. Electromyographic and MMG sensors were placed over the vastus lateralis muscle to monitor the electrical and mechanical aspects of muscle contractions, respectively. The testing protocol used for the first visit was repeated for the second visit, but the preexercise treatment (warm-up, no warm-up) not given during the first visit was administered. The results indicated that an active warm-up did not affect PT, RTD, or measures of muscle activation as reflected by EMG amplitude, EMG frequency, or MMG frequency (p > 0.05). However, MMG amplitude at 180°·s−1 was significantly greater in the warm-up condition compared with the no warm-up condition. The isolated increase in MMG amplitude suggested that warm-up may have affected the mechanical properties of muscle by reducing muscular stiffness or decreasing intramuscular fluid pressure, but that it was not sufficient to influence performance.

Exercise Physiology Laboratory and Center for Sport Performance, Department of Kinesiology, California State University, Fullerton, Fullerton, California

Address correspondence to Jared W. Coburn,

© 2012 National Strength and Conditioning Association