Lack of Sleep Reverses Muscle Gains for Men Over 40, According to a Sleep Specialist
You can take all the creatine you want, hit your protein goals daily, and never skip a workout, but without enough sleep, you’re still sabotaging muscle growth. Chronic sleep loss is a powerful stressor that increases the risk of metabolic issues and accelerates muscle breakdown. Studies have found that even a single night of total sleep deprivation can reduce your muscles’ ability to grow and push your body into a catabolic state.
"Sleep is when the body goes into repair mode, and this includes repairing muscle tissue damaged during exercise. During deep sleep, growth hormone is released, which plays a critical role in stimulating muscle protein synthesis and tissue regeneration," says Christopher Allen, MD, a board-certified sleep medicine physician and sleep science advisor at Aeroflow Sleep.
Lack of sleep is tough on anyone, but it’s especially challenging as we age. Men over 40 may experience changes in sleep patterns, including less deep sleep, more frequent nighttime awakenings, increased sleep fragmentation, and earlier wakeups, all of which make recovery even harder.
How Important is Sleep for Muscle Growth?
For men over 40, sleep becomes even more critical as the body’s natural recovery processes slow with age. When sleep is lacking, it's a domino effect: muscle recovery is impaired, inflammation rises, and gains from strength training can plateau or even reverse.
During deep sleep, growth hormone is released, but as deep sleep declines with age, men over 40 may produce less of it, limiting the body’s ability to repair muscle efficiently. Poor sleep also elevates cortisol, a stress hormone that breaks down muscle and hinders recovery.
It’s not just about time in the gym; it’s about understanding that sleep is when the real gains happen, as Allen says.
Sleep Loss Lowers Testosterone
You hear about it all the time, so you know how important testosterone is for muscle growth, strength maintenance, and overall vitality in men. Testosterone is produced during sleep. Most testosterone release occurs in the first few hours of uninterrupted, high-quality sleep, especially during REM and early morning hours.
"Sleep deprivation or fragmentation can blunt testosterone production significantly," Allen explains. "For men over 40, who already experience a natural decline in testosterone levels, poor sleep can accelerate this drop, which leads to reduced strength, slower recovery, decreased muscle mass, and increased fat storage.
Even one week of restricted sleep (about five hours per night) has been shown to reduce testosterone levels by 10 to 15 percent.
Related: This Overlooked Habit May Predict Your Lifespan Better Than Diet or Exercise, Study Says
Maximizing Sleep for Muscle Growth
Deep sleep, or slow-wave sleep, is the most critical stage for muscle repair and growth. This is when growth hormone secretion peaks, supporting cellular repair, tissue rebuilding, and protein synthesis.
"While REM sleep is essential for brain function, emotional regulation, and motor memory—which can aid athletic performance and coordination—it’s deep sleep that has the strongest physiological impact on muscular recovery and physical gains," Allen says.
Below are tips for getting more deep sleep:
- Go to bed on time, aiming for eight hours of sleep
- Avoid caffeine past noon
- Keep the bedroom dark and cold
- Limit screen time before bed
- Practice relaxation techniques, like breathwork, before bed
- Listen to pink noise
Related: What Sleep Doctors Want You to Know About 3 A.M. Wake-Ups and How to Fix Them