Effects of Short-Term Dynamic Constant External Resistance Training and Subsequent Detraining on Strength of the Trained and Untrained Limbs: A Randomized Trial

Sex Comparisons for Very Short-Term Dynamic Constant External Resistance Training

This study compared sex responses for strength and barbell velocity from very short-term resistance training (VST, consisting of 2-3 training sessions) for an upper body dynamic constant external resistance (DCER) exercise (bench press [BP]). Ten females (mean ± standard deviation (SD) age: 21.3 ± 3 years, height: 166.2 ± 6 cm, body mass: 71.4 ± 10.7 kg) and 10 males (mean ± SD age: 24.6 ± 4 years, height: 179.5 ± 8 cm, body mass: 88.6 ± 11 kg) completed a pre-test visit to determine the BP 1 repetition maximum (1RM) as well as the mean (BP_MV) and peak (BP_PV) barbell velocities from the BP 1RM. The VST involved three training visits where the participants performed 5 sets of 6 repetitions, at 65% of the 1RM. The post-test followed the same procedures as the pre-test visit. There were significant increases in 1RM strength for both the males (5.1%) and females (5.4%) between pre-test and post-test. There were no significance differences between sex for mean (BP_MV) and peak (BP_PV); however, overall there was a 32.7% increase in BP_MV and a 29.8% increase in BP_PV. These findings indicated an increase in strength and barbell velocity for both males and females as a result of VST upper body DCER exercise in untrained subjects.

Effects of isokinetic eccentric versus traditional lower body resistance training on muscle function: examining a multiple-joint short-term training model

Early adaptations in eccentric training show several advantages over those in concentric training. The purpose of this study was to quantify the effects of 4 weeks of multiple-joint eccentric versus traditional leg press (TLP) training on muscle strength, rate of torque development (RTD), and jump and sprint performance adaptations. Twenty-six resistance-trained adults performed either an eccentric or a TLP resistance-training program twice per week for 4 weeks. Single-joint isometric maximal and rapid strength (peak torque and RTD, respectively) and isokinetic strength of the knee extensors and flexors, multiple-joint eccentric strength, leg press strength (1-repetition maximum), 40-m sprint, and vertical and long jump were measured before, at the midpoint, and after a 4-week training period. Four weeks of isokinetic multiple-joint eccentric training elicited greater test-specific strength gains (effect size (ES) = 1.06) compared with TLP training (ES = 0.11). The eccentric group also yielded moderate improvements in the middle-late phase RTD (RTD100-200; ES = 0.51 and 0.54 for the knee flexors and extensors, respectively), whereas the TLP group showed small-moderate improvements (ES = 0.37). The majority of the single-joint strength variables showed negligible improvements. Performance tests showed no (broad jump) to small (vertical jump; sprint for the leg press) improvements. Multiple-joint eccentric training induced significant improvements in lower body strength in a short amount of time in a recreationally trained population. These accelerated adaptations along with the lower energy requirements of eccentric exercise, may be useful for clinicians or practitioners when prescribing training programs for those who are injured, sedentary, or elderly as a means to elicit time- and metabolically efficient muscle function improvements.