If you have specific strength or size goals, odds are you’ve optimized your waking hours for muscle growth and repair. You do the right workouts, fuel with the right nutrients, and take a stack of supplements that support gains. 

Still, if you’re not applying a similar level of strategy to your non-waking hours, you’re missing out. As far as your muscles are concerned, the hours you spend sleeping are just as important as, if not more important than, your waking hours. “Sleep is essential for making muscle gains as well as for helping your muscles recover from exercise,” says sleep specialist and neurologist, Dr. Chris Winter, M.D., author of The Sleep Solution and host of Sleep Unplugged. 

Ahead, learn more about why sleep is so essential for making muscle gains, and score helpful tips for getting the most bang for your bedtime buck. 

The Sleep and Muscle Recovery Connection

Sure, you need sleep in order to have the energy to keep your eyes open in the weight room. But that’s far from the only way sleep benefits your strength and muscle gains. When you sleep, your body releases two hormones that are essential for muscle repair: human growth hormone and testosterone. 

Released by the pituitary gland, human growth hormone supports muscle repair. An influx of human growth hormone  also triggers the release of a protein called insulin-like growth factor-I (IGF-I) that stimulates muscle, bone, and other tissue growth. It’s essential for repairing muscle wear-and-tear from exercise and day-to-day life, says Winter. 

Read More: 8 Foods That Are Important For Healthy Hormones

Testosterone also peaks while you sleep. Highest during REM, testosterone supports muscle mass by increasing muscle-protein synthesis, which is the process of amino acids being called on to repair microtears in the muscle fibers, Winter explains. 

“During deep sleep, blood flow to your muscles increases, which also aids in recovery and growth,” adds Dr. Shelby Harris, Psy.D., director of sleep health at Sleepopolis. Your blood is filled with vitamins and antioxidants that support muscle repair, she explains. 

Maximizing Muscle Gains Starts With Mastering Basic Sleep Hygiene 

Though there are a handful of specific tactics you can use to support your muscle repair while you sleep, you’ve got to implement some sleep hygiene basics first. “There are a few changes that you can make to your sleep space and routine that really can make a difference in your overall sleep quality,” says Harris. 

Start by creating a sleep oasis, suggests Harris. “That means making your bedroom a sleep-inducing environment that is dark and cool,” she says. The most ideal sleep temperature varies person to person, but hovers between 60 and 67 degrees Fahrenheit, per the National Sleep Foundation. 

You should also rid your space of electronics. Or, at the very least, cover their lights with tape to minimize the blue light exposure. A review published in the journal of Chronobiology International found that blue light exposure before bed can suppress melatonin production as well as decrease the amount of REM sleep, so, yes, this really is a must-do.

Next, establish a consistent sleep schedule. “The best thing you can do to improve your sleep quality and quantity is go to bed and wake up at the same time every day,” says Harris. Your circadian rhythm regulates your body processes over each 24-hour period, so when you wake up and fall asleep at the same time each day, your body begins to recognize when it’s supposed to rise and rest each day, helping you fall asleep more quickly and wake up feeling more energized. 

3 Tips For Hacking Your Sleep For Better Muscle Gains 

Once you’ve got the basics down, you can support your fitness goals while you sleep to an even greater degree by implementing a few smart hacks. Here are three science-backed tips for improving muscle growth while you sleep. 

1. Stop working out at Least Three Hours before bed

Everyone has different preferences around when they like to sweat. But if possible, you want to be leaving the gym at least three hours before you’re planning to snooze—especially if you exercise vigorously, says Harris. “After exercise, it takes time for your body temperature and heart rate to return back to normal,” she explains. This, then, impacts your sleep.

Indeed, one study published in the journal Sports Medicine found those that did high-intensity interval training before bed had a hard time falling asleep. The study found that the delay was caused, in part, by the fact that their heart rates were still more than 20 beats per minute faster than their resting heart rate an hour after exercise. 

Read More: 4 Post-Workout Game-Changers for Maximum Muscle Recovery

If the very tail end of the day is the only time you can fit in a workout, consider opting for a lower-intensity workout like steady-state cardio, yoga, or moderate lifting, instead. The researchers behind that study also found that moderate-intensity exercise shortly before bed did not negatively impact sleep. 

2. Avoid alcohol

Drinking alcohol does a doozy on your ability to dream. “It impacts your sleep quality and quantity,” says Winter. In fact, one 2018 study published in the Handbook of Clinical Neurology linked alcohol consumption with chronic sleep disturbances, less slow-wave sleep, and more rapid-eye-movement (REM) sleep than normal. Meanwhile, a second study published in Nutrition & Metabolism found that consuming alcohol before bed cuts down on the release of human growth hormone and testosterone while you’re asleep. 

If you are going to drink, Harris says it’s best to give yourself three hours between when your lips last touch the bottle and when your head hits the pillow. This gives the body time to metabolize some of the alcohol in your system, she explains. 

3. Snack on casein 

Got a late-night sweet tooth? Do your muscles a favor and make your evening snack one that packs a casein protein punch. 

A type of protein that comes from milk, casein protein is a slower-digesting protein compared to other protein sources, like whey. Because it takes longer to digest than other protein supplements, casein protein feeds your body with smaller amounts amino acids for a sustained period of time, according to research published in Nutrients. 

The body uses amino acids to repair the microtears shorn into your muscle fibers during exercises—and because casein takes longer to digest, it gives your body access to the tools it needs to recover all throughout the night, Harris explains. “The result is greater muscle recovery,” she says. 

Indeed, in a 2017 review published in Sport and Exercise Nutrition, those who consumed 40 grams of casein protein before bed saw a 22 percent higher rate in overnight muscle protein synthesis compared to those who did not. 

For a serving of casein in a dessert-like form, Harris recommends making casein pudding by mixing together a serving of casein protein powder with five to 10 ounces of almond milk or milk. Let the mixture sit in the fridge for a few minutes to thicken before chowing down.