Same-session Versus Different-Day Combined Strength And Endurance Training: Effects On Body Composition In Women

Training for strength (S) and endurance (E) in the same session has previously been shown to induce similar changes in body composition and physical performance independent of the exercise order (1). Training S and E on different days requires more frequent individual training sessions to match the training volume, possibly resulting in higher post-exercise energy consumption (2). PURPOSE: To compare changes in body composition and physical fitness during same-session (SS) and different-day (DD) combined S and E training in women. METHODS: Physically active women were assigned to a SS (n=23, 30±5 yrs, 165±6 cm, 64±10 kg) or DD (n=18, 30±8 yrs, 168±5 cm, 66±8 kg) group and trained 2-3 d·w-1 (S and E in one session) or 4-6 d·w-1 (S and E on alternating days) for 24 wks. The exercise order for SS was randomized and maintained throughout 24 wks (S preceding E or vice versa). Lean and fat mass were assessed by DXA for upper (UB), lower (LB) and total body (TB). Maximal dynamic leg press strength (1RM) and endurance performance (maximal Watts, Wmax) during an incremental cycling test were measured. Subjects were required to maintain normal dietary intake throughout the intervention. RESULTS: DD significantly decreased fat mass (UB -16±16% p=0.002, btw-groups p<0.001; LB -10±13% p=0.018, btw-groups p=0.002; TB -13±14% p=0.004, btw-groups p<0.001), while changes in fat mass in SS were not significant (p>0.05). Both SS and DD increased lean mass in UB (SS 3±4% p=0.019 and DD 5±6% p=0.006), LB (SS 3±3% p=0.001 and DD 4±2% p<0.001) and TB (SS 3±2% p<0.001 and DD 5±3% p<0.001, btw-groups p=0.039). Body weight remained unchanged (p>0.05) in both groups. Both training modes increased 1RM (SS 17±11%, p<0.001 and DD 21±8%, p<0.001) and Wmax (SS 13±9%, p<0.001 and DD 22±14%, p<0.001). CONCLUSION: The main finding was that both SS and DD significantly increased lean mass and S and E performances, but reductions in fat mass were only observed following DD training. This may be due to possibly increased post-exercise energy demands in DD due to more frequent individual training sessions. Thus, DD training may be recommended for individuals aiming to optimize body composition. References: 1. Schumann et al. 2014 MSSE, 2. Almuzaini et al. Can JAP 1998