Sleep is a foundation of good health, and it plays an important role for anyone working to build strength and muscle. For lean adults who find it hard to gain weight, paying attention to sleep can be just as important as the time spent in the gym. This guide explains how much sleep adults need, why it matters, and practical habits you can build tonight, drawing on recommendations from the National Heart, Lung, and Blood Institute (NHLBI), the Centers for Disease Control and Prevention (CDC), and the UK National Health Service (NHS).
How Much Sleep Adults Need
According to the NHLBI, experts recommend that adults sleep between 7 and 9 hours a night. Adults who sleep less than 7 hours a night may have more health issues than those who sleep 7 or more hours a night. The NHLBI also notes that sleeping more than 9 hours a night is not necessarily harmful and may be helpful for young adults, people recovering from sleep deprivation, and people who are sick.
The CDC provides more detailed age-based recommendations. For adults aged 18 to 60 years, the CDC recommends 7 or more hours of sleep per night. Adults aged 61 to 64 years should aim for 7 to 9 hours, and those 65 years and older should get 7 to 8 hours. These numbers are based on consensus statements from sleep research organizations.
Why Sleep Matters for Your Health
The CDC lists several health benefits of getting enough sleep. Good sleep can help you get sick less often, stay at a healthy weight, and reduce stress while improving your mood. It also supports heart health and metabolism, and may lower your risk of chronic conditions such as type 2 diabetes, heart disease, high blood pressure, and stroke. Additionally, adequate sleep lessens the risk of motor vehicle crashes and related injuries, and it improves attention and memory to help you perform daily activities better.
These benefits are especially relevant if you are following a training program. Feeling alert and in a positive mood can make it easier to stay consistent with workouts, and a well-functioning metabolism supports the energy balance needed for muscle gain. Sleep is also one of the recovery habits covered in our recovery guide.
Healthy Sleep Habits
Both the NHLBI and the NHS offer practical steps to improve your sleep habits, sometimes called sleep hygiene. The NHLBI emphasizes giving yourself enough time to sleep and protecting that time, because sleep is often the first thing busy people sacrifice. Making sleep a priority can help you feel happier and more productive during the day.
Stick to a Schedule
The NHLBI advises going to bed and waking up at the same time every day, even on weekends. Try to limit the difference to no more than about an hour. The NHS agrees that a regular sleep routine helps your body know when it is time to sleep, making it easier to fall asleep.
Create a Relaxing Bedtime Routine
The hour before bed should be a quiet time. The NHLBI recommends avoiding intense exercise and bright artificial light from screens, because light can signal your brain that it is time to be awake. The NHS also suggests avoiding phones, tablets, and computers for at least an hour before bed, as the blue light can make it harder to fall asleep. Instead, try reading, meditation, breathing exercises, or listening to calming music or a podcast.
Optimize Your Bedroom
Keep your bedroom quiet, cool, and dark, says the NHLBI. The NHS adds that you can use earplugs, an eye mask, or white noise if needed. Fully closing curtains and keeping clocks out of view can also reduce light disturbances. Adjusting the temperature or opening a window (if safe) may help make the room cooler.
Watch What You Eat and Drink
Avoid heavy or large meals within a few hours of bedtime, though a light snack is okay. The NHLBI warns against alcoholic drinks before bed, as well as nicotine and caffeine. The NHS similarly notes that tea, coffee, and some soft drinks contain caffeine, and that alcohol and nicotine can disrupt sleep. A warm milky drink or herbal tea may be a better choice before bed.
Manage Worries and Stay Active
The NHS suggests that if you often worry in bed, try writing a to-do list for the next day before you go to sleep. This can help clear your mind. Regular physical activity also improves sleep, but if exercising close to bedtime affects your sleep, try being active earlier in the day. The NHLBI recommends spending time outside every day when possible and being physically active.
What to Do If You Cannot Sleep
The NHS advises against forcing sleep. If you are still awake after about 20 minutes, get up and sit somewhere comfortable. Do a relaxing activity like gentle yoga, reading, or listening to quiet music, and go back to bed when you feel sleepy. The NHLBI adds that napping can boost alertness, but if you have trouble falling asleep at night, limit naps or take them earlier in the afternoon. Adults should nap for no more than 20 minutes.
Sleep and Your Training Routine
For someone trying to build muscle, sleep is a critical piece of the recovery puzzle. The CDC links enough sleep to better attention, memory and mood, all of which help you train consistently. If you are following a strength progression plan, consistent sleep helps you show up ready to perform. Our article on how recovery supports strength progress explains more about the role of rest between workouts. And for a broader look at building a recovery routine, visit the Recovery and Progress section.
Remember that sleep is just one part of recovery. Pairing good sleep with proper nutrition, hydration, and rest days supports your training. If you are a lean adult who struggles to gain weight, do not underestimate the power of a full night’s sleep as part of your overall plan.
When to Talk to a Doctor
The CDC advises that you talk to your healthcare provider if you regularly have problems sleeping or notice signs of common sleep disorders such as insomnia, restless legs syndrome, narcolepsy, or sleep apnea. Your provider may ask you to keep a sleep diary that tracks when you go to bed, wake up, nap, exercise, and consume alcohol or caffeine. The NHLBI also recommends speaking with a doctor if you think you are sleeping too much or too little, or if you have trouble adapting to a shift-work schedule.
Frequently Asked Questions
How many hours of sleep do adults need?
The NHLBI recommends 7 to 9 hours per night for adults. The CDC breaks it down further: adults aged 18 to 60 should get at least 7 hours, those 61 to 64 need 7 to 9 hours, and those 65 and older need 7 to 8 hours.
What are signs of poor sleep quality?
According to the CDC, signs of poor sleep quality include trouble falling asleep, repeatedly waking up during the night, and feeling sleepy or tired even after getting enough sleep. If you experience these regularly, consider speaking with a healthcare provider.
Can better sleep help my workouts?
The CDC says getting enough sleep can improve attention and memory and reduce stress while improving mood, which may help you stay consistent with your training. For more on how sleep fits into a muscle-building routine, explore our Sleep and Training hub.
For more practical advice on rest, recovery, and building strength, visit the Sleep and Training category page.
