Abstract
The absence or decrease in sleep time can affect different mechanisms associated with changes in body composition and physical exercise performance. However, it is unclear in the literature how chronically sleep-restricted individuals respond to strength training. Thus, this study aimed to evaluate the effects of reducing between one and two hours of recommended sleep time (7 hours) on the response to resistance training. The study included 12 subjects who slept on average 2 hours less than the recommended 7 hours per day (42 ± 8 years; 84.9 ± 11.6 kg; 27.9 ± 3.5 kg/m (2) ; 6:17 ± 22 total sleep time/day and 5: 47 ± 29 sleep time/night) and 12 subjects with recommended sleep time (38 ± 11 years; 78.3 ± 9.5 kg; 25.1 ± 3.5 kg/m (2) ; 7:47 ± 38 total sleep time/day and 7:16 ± 54 sleep time/night) and a control group (42 ± 7 years; 81 ± 12.2 kg; 26.2 ± 4.0 kg/m (2) ; 7:30 ± 40 total sleep time/day and 7: 17 ± 51 sleep time/night) that did not perform resistance training. A total of 16 resistance training sessions were performed, 3 times a week (Sessions= 4 exercises; 2 sets; maximum repetitions to failure). The maximum number of repetitions, arm circumference, and arm muscle area increased, while triceps skinfold decreased after training in the experimental groups ( p < 0.05), with no changes for the control group. There was no difference in muscle mass, body mass index, or sleep variables (sleep time, latency, efficiency) after the training period in either group (p> 0.05). Thus, the chronic 1-2-hour reduction in average recommended sleep time was not able to affect the positive effects of resistance training.