Order effect of an 8‑week concurrent training program on the maximal fat oxidation

Abstract

Background Concurrent training (CT) is a common method used in health-oriented training programs. However, its design needs to be explored in order to inform practitioners about the most effective methods to improve different health-related markers (e.g., maximal fat oxidation [MFO]). Thus, this study aims to determine the order effect of an 8 week CT on the MFO of recreationally trained young adults. Methods Twenty participants were allocated in two different groups to perform the CT differing only in the exercise sequence. The endurance training (ET) consisted of 4 to 6 repetitions of 30 s all-out running sprints with 4 min of active recovery. The resistance training (RT) consisted of 4 to 6 sets at 60 to 80% of the one-repetition maximum with 5 to 1 repetition in reserve of back squat and bench press exercises. 15 min of rest were established between exercise modes. Previous and after the CT program, participants performed a graded exercise test where MFO was determined. Results There was a significant time effect on MFO (p = 0.044). A moderate increase was observed in both ET + RT (Mean change: 0.11 [− 0.02 to 0.25] g/min; Effect size: 0.61 [− 0.12 to 1.35]) and RT + ET (Mean change: 0.07 [− 0.01 to 0.16] g/ min; Effect size: 0.62 [− 0.12 to 1.36]) groups. No significant interaction was observed (p = 0.658). Conclusions The 8 week CT program improved the muscle oxidative capacity of recreationally trained young adults regardless of the exercise sequence.