Comparison of Resistance Exercise Perceived Exertion and Muscle Activation at Varied Submaximal Durations, Loads, and Muscle Actions.

Hollander, DB, Worley, JR, Asoodeh, M, Wakesa, D, Magnuson, M, Dantzler, DK, Didier, JJ, and Kraemer, RR. Comparison of resistance exercise perceived exertion and muscle activation at varied submaximal durations, loads, and muscle actions. J Strength Cond Res 31(5): 1387-1394, 2017-Previous studies investigating muscle activation from dynamic, plate-loaded, concentric (CON) and eccentric (ECC) muscle contractions have not accounted for the greater absolute strength of ECC contractions. The purpose of the study was to determine the effect of different dynamic muscle contraction durations, loads, and contraction types (CON and ECC) on perceived exertion and muscle activation differences in 6 women (mean ± SD age, height, weight, body mass index 22.83 ± 2.56 years, 1.65 ± 0.261 m, 68.56 ± 2.72 kg, 25.26 ± 4.39 kg·m). The participants were recruited and trained to move weight at the appropriate duration (2, 3, 4, and 5 seconds) for leg extension using a displacement apparatus (sonic emitter, auditory) and a computer program (visual feedback of bar displacement). Concentric and ECC 1 repetition maximum (1RM) were determined for leg extension for the midrange 3-second duration. Thirty, 50, and 70% of either CON or ECC 1RM were loaded for the remainder of the sessions. Subjects were then assigned to complete trials in a counterbalanced fashion for load, contraction type, and contraction duration. Rating of perceived exertion (RPE) significantly increased in response to load (30, 50, and 70%) regardless of contraction type as did electromyography (EMG) root mean square amplitude. Greater time under tension significantly increased RPE regardless of contraction type during knee extension exercise. The EMG amplitude was less distinguishable between 2, 3, 4, and 5 seconds of contractions. The data highlight the effort sense distinctions made by women at submaximal exercise loads during knee extension. These findings should be used to develop effective resistance exercise protocols that facilitate positive perceptions and adherence resistance exercise loads, durations of contraction, and contraction type.

Effects of gender on physiological responses to strenuous circuit resistance exercise and recovery.

Few studies have focused upon the physiological responses to circuit weight training (CWT) in men and women, and an investigation of possible gender differences could lead to optimal exercise prescriptions and improved adaptation outcomes. The purpose of the study was to determine the effects of gender on cardiovascular and metabolic responses to CWT and consequent recovery. Ten healthy men and 10 healthy women completed an initial session to collect descriptive data and determine a 12 repetition maximum (12RM) for 6 different upper- and lower-body resistance exercises. This was followed by 2 identical sessions of a CWT protocol on 2 separate days at least 48 hours apart. The first session was used to familiarize subjects with the equipment and the testing protocol. The second session was used to determine physiological responses. Each subject performed 10 repetitions of 6 exercises for 3 circuits at a 12RM load. Vo2 and respiratory exchange ratio (RER) were continuously monitored, whereas heart rate (HR) and blood pressure (BP) were taken at the end of each circuit. Across the exercise session, men revealed greater absolute and relative Vo2, relative lean body mass Vo2, systolic BP (SBP), RER, and recovery Vo2 when compared with the female subjects. There were no differences in HR, diastolic BP (DBP), or recovery RER. The present study provides a greater insight into gender differences in cardiovascular and metabolic responses to circuit weight training. These gender differences should be taken into consideration for development of CWT protocols for men and women.