Effect of Different Reduced Training Frequencies After 12 Weeks of Concurrent Ballistic and Aerobic Training on Muscle Power and Triceps Brachii Muscle Architecture.

The aim of the present study was to investigate the effect of two long-term reduced concurrent training frequencies (incorporating power training for the upper and high-intensity interval aerobic training for the lower extremities), in which participants performed one training session every either 7 or 14 days, after 12 weeks of systematic concurrent training on upper extremities' muscle strength, power, and morphology in young females. After a 12-week concurrent resistance and aerobic training period, participants were assigned into three groups and performed either one training session every 7 days (G7), or once every 14 days (G14), or detraining (GD) for 12 weeks, followed by 12 additional weeks of detraining. Performance and muscle mass increased after the initial 12-week training period. After the reduced training frequency period, bench press 1-RM and aerobic power remained unchanged in G7 and decreased significantly in G14 (-5.9 ± 4.9%; -1.4 ± 4.5%). Muscle power and muscle thickness of the triceps branchii long head decreased significantly in G7 (-9.8 ± 7.7%; -0.9 ± 0.6%; respectively, < 0.05) and G14 (-10.9 ± 7.6%; -2.8 ± 2.7%, respectively, < 0.05), without significant differences between groups ( > 0.05). In conclusion, 12 weeks of systematic concurrent resistance (upper extremities) and aerobic training (lower extremities) induced significant improvements in upper extremities muscle power/strength and muscle architecture characteristics. Both reduced training frequencies led to significant reductions in power performance. Thus, performing one training session every 2 weeks for 3 months may preserve 90 to 95% of the muscle power/strength, aerobic power and 72% of muscle mass adaptations achieved with systematic concurrent training. However, greater preservations in the above parameters could be observed if the training frequency is one training session per week.