Fitness and lean mass increases during combined training independent of loading order

Abstract. Purpose: Although the benefits of combined endurance (E) and strength (S) training for the development of physical fitness and health are well known, scientific examination of the effect of loading order when E and S are combined into the same training session (E+S vs. S+E) is rare. This study investigated the effects of moderate frequency E+S versus S+E training on physical fitness, body composition and blood lipids. Methods: Physically active and healthy young men performed E+S (n=16) or S+E (n=18) training, 2-3 x·wk-1 for 24 weeks. Endurance (by incremental bike test) and strength (by dynamic leg press) performance as well as body composition (by DXA), muscle cross-sectional area of vastus lateralis (by ultrasound) and blood lipids were determined before and after the intervention. Results: Time to exhaustion, aerobic power (W) and 1RM strength significantly increased in the two groups at week 24 (E+S 12-15%,p=0.003-0.001; S+E 16-17%,p<0.001) but no between-group difference was observed. Similarly, the two groups significantly increased total lean mass (E+S 3%, S+E 3%, both p=0.001) and muscle cross-sectional area (E+S 14%, p=0.001; S+E 16%, p<0.001) at week 24 to a similar extent. No sig nificant changes in body fat or blood lipids were observed in either of the two groups at week 24. Conclusion: These results showed that moderate frequency (2-3 x·wk-1) combined E+S or S+E training led to significant improvements in physical fitness and lean body mass but did not induce significant changes in body fat or blood lipids. Furthermore, as no between-group differences were observed, these results indicate that loading order does not seem to affect training adaptations of healthy moderately active young men.