Neuromuscular adaptations to combined strength and endurance training: order and time-of-day

The present study examined the effects of 24 weeks of morning vs. evening same-session combined strength (S) and endurance (E) training on neuromuscular and endurance performance. Fifty-one men were assigned to the morning (m) or evening (e) training group, where S preceded E or vice versa (SEm, ESm, SEe and ESe), or to the control group. Isometric force, voluntary activation, EMG and peak wattage during the maximal cycling test were measured. Training time did not significantly affect the adaptations. Therefore, data are presented for SEm+e (SEm+SEe) and ESm+e (ESm+ESe). In the morning, no order specific gains were observed in neuromuscular performance. In the evening, the changes in isometric force (SEm+e 15.9±16.7%, p=0.001; ESm+e 4.1±12.2%, p=0.615) and EMG (SEm+e 38.3±31.7%, p=0.001; ESm+e 14.67±36.44%, p=0.486) were larger (p=0.014) in SEm+e than in ESm+e and in voluntary activation larger (p=0.026) in SEm+e compared to controls. Peak wattage increased in the morning (SEm+e 15.9±9.2%, ESm+e 22.0±7.0%; p<0.001) and evening (SEm+e 16.3±7.2%, ESm+e 21.0±9.0%; p<0.001) but were larger (p<0.05) in ESm+e. The current training program led to greater neuromuscular adaptations when SE-training was performed in the evening, whereas the ES-training provided more optimal conditions for endurance performance adaptations both in the morning and evening.