Comparison of the Effects of Eccentric, Concentric, and Eccentric-Concentric Isotonic Resistance Training at Two Velocities on Strength and Muscle Hypertrophy.

Ünlü, G, Çevikol, C, and Melekoglu, T. Comparison of the effects of eccentric, concentric, and eccentric-concentric isotonic resistance training at two velocities on strength and muscle hypertrophy. J Strength Cond Res 34(2): 337-344, 2020-The aim of this study was to compare the effects of concentric, eccentric, and eccentric-concentric isotonic resistance training at both fast and slow velocities to determine whether contraction modality affects muscle strength and hypertrophy. Forty-one young, healthy males (mean age 21.1 ± 1.8 years; height 178.9 ± 6.1 cm; body mass 70.5 ± 9.8 kg; and body mass index 22.0 ± 2.6 kg·m) were randomly assigned for 12 weeks to 1 of 5 resistance training groups to perform leg extension exercises 3 days a week (fast-eccentric; fast-concentric [FC]; slow-eccentric [SE]; slow-concentric; and concentric-eccentric [CE], 30°·s for slow and 180°·s for fast contractions), or to a nontraining control group (CG). Isotonic strength (1 repetition maximum [1RM]), isokinetic strength (peak torque), and quadriceps femoris muscle volume were measured before and after the 12 weeks of training program. In the early phase of the training period (first 3 weeks), the 1RM values of SE, FC, and CE increased remarkably (19.70, 13.73, and 19.35%, respectively; p < 0.05). Significant increases compared with the CG were found for muscle isotonic strength (∼25-41%, p < 0.001) and isokinetic peak torque at 60°·s (∼13-32%, p < 0.05) in all training groups after the 12 weeks of the training period. No statistically significant interactions between the group and time were found on isokinetic peak torques at 180°·s and muscle volume. Our results, therefore, suggest that all the training modalities in our study have the potential to induce isotonic strength gain in knee extensors, and there is insufficient evidence for the superiority of any specific mode of muscle contraction or velocity.

The Effects of a Physically Active Lifestyle on the Health of Former Professional Football Players.

The purpose of this investigation was to determine if a physically active lifestyle affects the health of former football players. Sixty former professional football players aged 40⁻50 years and who ended their sports career at least ten years ago were recruited for the study and grouped into two groups based on their physical activity habits after their retirement. Health and lifestyle characteristics were collected through a questionnaire to obtain information about recreational physical activity levels, diseases, family medical history, smoking, alcohol intake and dietary habits. Furthermore, lung functions, blood parameters and cardiovascular health were evaluated. Our results showed that body weight and body fat percentage were significantly higher in retired footballers who had a sedentary lifestyle compared to those who were physically active. The absolute and predicted values for forced expiratory volume in one-second values were higher in the active group. Twelve retired athletes were found to have intraventricular conduction delay. The findings suggest that former footballers who have higher levels of physical activity have advanced body composition, respiratory functions and serum lipids compared to former footballers with less active lifestyles. It is recommended that former elite athletes should maintain physically active lifestyles to sustain their health and reduce the risk of disease and disability in the later years of life.