The effect of sleep restriction, with or without high-intensity interval exercise, on myofibrillar protein synthesis in healthy young men.
Level 2 - randomized trial
Small parallel-group controlled human intervention trial with matched allocation
PubMed 32078168 · doi:10.1113/JP278828
What was done
Twenty-four healthy young men completed a protocol consisting of two nights of baseline sleep followed by a 5-night intervention period. Participants were matched for age, VO2peak, BMI, and habitual sleep duration into three parallel groups (n = 24 total): normal sleep (8 h time in bed each night), sleep restriction (4 h time in bed each night), and sleep restriction plus exercise (4 h time in bed each night, with three sessions of high-intensity interval exercise [HIIE]). Deuterium oxide dosing and pre- and post-intervention muscle biopsies were used to measure myofibrillar protein synthesis (MyoPS) and signaling markers of protein synthesis and degradation.
What was found
MyoPS fractional synthetic rate (% day^-1) was significantly lower in the sleep restriction group (mean ± SD: 1.24 ± 0.21) compared to the normal sleep group (1.53 ± 0.09) and the sleep restriction plus exercise group (1.61 ± 0.14) (P < 0.05). There were no observed changes across groups in molecular markers of protein synthesis signaling (p-AKT ser473, p-mTOR ser2448) or degradation pathways (Foxo1/3 mRNA, LC3 protein).
Why it matters
This study provides direct evidence that acute sleep loss impairs myofibrillar protein synthesis in humans, identifying a key cellular mechanism for sleep-loss-associated muscle wasting. It demonstrates that performing high-intensity interval exercise can fully preserve muscle protein synthesis rates during severe short-term sleep restriction.
Limits
The sample size was small (24 participants across three groups) and comprised only healthy young men, limiting generalizability to women, older individuals, or clinical populations. The intervention lasted only five nights, and whole-body muscle mass changes or long-term functional adaptations were not measured.
Cited by
- contradicts Sleep disruption can have more of an impact on muscle protein synthesis in the body than dietary protein intake.