Working Out on 5 Hours of Sleep: Advice for Tired Dads

The toddler finally settles. You check the clock, calculate what's left before your alarm, and realize your morning workout will come after another five-hour night.

Getting up anyway can feel like the disciplined choice. But if training repeatedly means cutting an already short night shorter, your schedule deserves another look.

Sleep physician Christopher Allen, M.D., recommends prioritizing the extra sleep when the choice is between that and an early workout on fewer than seven hours. Moving the session—or making it shorter—can help you keep both habits.

The American Academy of Sleep Medicine and Sleep Research Society recommend at least seven hours regularly for healthy adults ages 18 to 60. Parenting can make that difficult. It doesn't make the need disappear.

In its public survey findings, Aeroflow Sleep reports that 43 percent of surveyed parents get five hours of sleep or less each night. Aeroflow Sleep connects patients with sleep-apnea equipment covered by private insurance, Medicaid, or Medicare plans, and the findings describe respondents' experiences rather than establishing how all parents sleep.

"You start to feel normal being tired, but your performance continues to decline," says Allen, a paid sleep science advisor to Aeroflow Sleep.

That gap between feeling functional and performing well has appeared in laboratory research. In a 2003 study, adults restricted to six hours in bed nightly for two weeks developed accumulating cognitive deficits. Their ratings of sleepiness rose much less dramatically.

Getting accustomed to the feeling of a short night doesn't necessarily mean your attention has recovered.

"Perceived exertion goes up, so you'll feel like the weight is heavier," Allen says.

Researchers have also measured changes in muscle protein synthesis, the process involved in maintaining and building muscle. In a 2021 crossover study of 13 healthy young adults, a night of total sleep deprivation reduced muscle protein synthesis after eating by 18 percent compared with normal sleep.

That experiment involved an all-nighter. It does not show that sleeping five hours reduces your gains by 18 percent, or that one bad night erases a workout.

Weight management may become harder, too. In a small 2010 trial, 10 adults with overweight completed two periods of calorie restriction with either 5.5 or 8.5 hours allotted for sleep nightly. During the shorter-sleep condition, they lost less fat and more fat-free mass, despite similar total weight loss.

Fat-free mass includes water and other tissues as well as muscle. Still, the findings suggest that the scale alone may miss how sleep affects the outcome of a diet.

For more on the recovery process, see our guide to what happens to your muscles between workouts.

The often-cited number comes from a 2011 study of just 10 healthy young men. After roughly a week of five-hour nights, their daytime testosterone levels were 10 to 15 percent lower than under the rested condition.

But subsequent findings have been mixed. Later controlled studies did not find significant adverse effects on testosterone under the sleep-restriction schedules they tested.

The evidence supports taking sleep seriously. It does not justify predicting a specific testosterone drop for every tired dad—or describing a short week of sleep as aging him by a decade.

Start with the part of the schedule you can change. A child's nighttime waking may be outside your control; the alarm for an optional early workout may be more flexible.

Move or shorten the session. Allen recommends reconsidering the early workout when it comes at the expense of needed sleep. A lunch break or shorter session may fit better during a stretch of disrupted nights.

Plan rest together. Carleara Weiss, Ph.D., R.N., a sleep researcher and paid Aeroflow Sleep advisor, recommends coordinating childcare and rest with your partner where possible. Discuss who can cover a wake-up or create a protected window for the other person to sleep.

"Prioritizing sleep matters just as much for dads as it does for moms," Weiss says.

Check your caffeine timing. Allen suggests leaving roughly eight hours between caffeine and bedtime. The National Heart, Lung, and Blood Institute notes that caffeine's effects can last that long. Include pre-workout supplements and energy drinks when reviewing what you consume.

Use a short nap when there's an opening. NHLBI recommends adult naps of no more than 20 minutes. If naps make falling asleep at night harder, take them earlier or limit them. They may improve alertness, but they don't make chronically short nights adequate.

Loud, frequent snoring, gasping during sleep, or breathing pauses noticed by a partner warrant a conversation with a healthcare professional. These are recognized symptoms of sleep apnea, which may require a sleep study to diagnose.

You don't need to wait until you have perfected your bedtime routine to raise those symptoms. Persistent daytime sleepiness also deserves attention.

For the next disrupted night, decide in advance whether the morning session can move. That gives you an alternative to making the same exhausted calculation when the alarm rings.

Christopher Allen and Carleara Weiss are paid sleep science advisors to Aeroflow Sleep, which connects patients with sleep-apnea equipment covered by private insurance, Medicaid, or Medicare plans. The company's survey findings are self-reported and are separate from the peer-reviewed studies discussed here.

This article provides general health and fitness information, not individualized medical advice. Consult a qualified healthcare professional about persistent sleep problems, excessive daytime sleepiness, or possible sleep apnea.

This story was originally published by Men's Fitness on Oct 14, 2026, where it first appeared in the Training section. Add Men's Fitness as a Preferred Source by clicking here.