Author(s): MPAMPOULIS, T., STASINAKI, A., ZARAS, N., BOGDANIS, G., TERZIS, G., Institution: NATIONAL AND KAPODISTRIAN UNIVERSITY OF ATHENS, Country: GREECE, Abstract-ID: 459

INTRODUCTION:
Systematic concurrent resistance and aerobic training results in substantial increases in muscle strength and mass as well as major improvements in various health indices. Yet, sports enthusiasts are often forced to reduce their training frequency or completely abstain from training for certain periods due to lack of time or mild injuries. Nevertheless, it remains unclear whether reducing training frequency, without reducing training intensity, might result in preservation of muscle strength and mass achieved during the systematic training period. The purpose of this study was to investigate the effect of concurrent resistance and aerobic training once per week or once every two weeks, on muscle strength and mass, after a period of 12 weeks of systematic concurrent resistance and aerobic training performed twice per week.
METHODS:
Twenty young moderately-trained women (height 164±4.8cm, mass 60,9±6.1kg), with no experience in systematic resistance exercise, followed 12 weeks of lower body resistance training [leg press, 4 sets X 6 repetitions, 80% of maximal strength (1-RM), 2/week] and high intensity interval bicycling (10X1min, at 100% aerobic power, with 1 min rest between bouts). After this 12-week training period, participants were equally assigned into 2 groups: one group trained once per week (G7), while the other group trained once every two weeks (G14), for another 12 weeks, with the training intensity and volume used at the last training session of the initial 12 weeks. Leg press 1-RM and quadriceps muscle cross sectional area (CSA, via ultrasonography) were evaluated before (T1), at the end of 12 weeks of systematic training (T2), after 6 weeks (T3) and after 12 weeks (T4) of reduced training frequency. Data were treated with repeated measures ANOVA and Tuckey post-hoc test (statistical significance was set at p≤0.05).
RESULTS:
Leg press 1-RM and quadriceps CSA increased after systematic training (G7: 29.6±13.8% and 14.2±4.9%, respectively; G14: 29.9±7.9% and 14.5±3.6%, respectively, p<0.05). Leg press 1-RM remained unchanged for both groups after 6 weeks of reduced training frequency. Leg press 1-RM and quadriceps CSA decreased only in G14 after 12 weeks of reduced training frequency compared to T2 (2.9±2.5% and 5.9±1.7% respectively, p<0.05).
CONCLUSION:
These results suggest that muscle strength of the lower extremities is well preserved with only 3 training sessions in 6 weeks (once every 14 days), after a period of systematic concurrent training. If this bimonthly training frequency is continued for 6 more weeks both muscle strength and mass decrease significantly, yet most of the resistance training-induced improvements are preserved. Therefore, performance of one training session every 2 weeks for 3 months after cessation of systematic concurrent training may preserve up to 90% of the muscle mass and strength adaptations achieved, if the training intensity and volume are sufficient.