Getting enough quality sleep is crucial for muscle growth and recovery after intense exercise. The recommended amount of sleep for most adults is 7-9 hours per night. However, some people wonder if getting just 7 hours is sufficient to support muscle building when following a rigorous training program.
How Much Sleep Do You Need?
The amount of sleep needed can vary between individuals based on factors like age, activity level, and genetics. Here are some general sleep recommendations:
- Newborns (0-3 months): 14-17 hours
- Infants (4-11 months): 12-15 hours
- Toddlers (1-2 years): 11-14 hours
- Preschoolers (3-5 years): 10-13 hours
- School-age children (6-13 years): 9-11 hours
- Teenagers (14-17 years): 8-10 hours
- Adults (18-64 years): 7-9 hours
- Older adults (65+ years): 7-8 hours
As you can see, most health organizations recommend that adults get 7-9 hours of shuteye each night. But is the minimum end of that range enough when you are intensely training and trying to build muscle mass?
Muscle Growth Occurs During Sleep
Muscle growth does not solely occur during strength training workouts. In fact, experts suggest that the majority of muscle building happens during rest and sleep. This is because sleep provides the ideal environment for muscle recovery and the release of key hormones involved in muscle repair and growth, such as testosterone and human growth hormone.
During sleep, your levels of cortisol (a stress hormone) are lowered, allowing for enhanced muscle protein synthesis – the process of building new muscle tissue. Without enough quality sleep, cortisol remains elevated, impeding optimal muscle growth.
Lack of Sleep Impacts Muscle Building Hormones
Getting insufficient rapid eye movement (REM) and deep sleep can negatively impact hormones that play a role in muscle growth, including:
- Testosterone: Low levels are linked to reduced muscle mass and strength.
- Human growth hormone (HGH): Critical for muscle growth and tissue repair. Lower secretion is tied to less lean body mass.
- Insulin-like growth factor 1 (IGF-1): Works with growth hormone to increase muscle mass. Lower levels can impair protein synthesis.
Research shows that restricted sleep of less than 7 hours per night can significantly decrease circulating levels of these anabolic hormones, potentially inhibiting muscle gains.
The Importance of REM and Deep Sleep for Muscle
Non-rapid eye movement (NREM) deep sleep and REM sleep play important yet different roles in muscle recovery and growth.
During deep sleep:
- Blood supply increases to the muscles.
- Tissue growth and repair accelerates.
- Growth hormone is secreted.
During REM sleep:
- Protein synthesis ramps up in muscle fibers.
- The nervous system rests.
- Hormones like cortisol and testosterone are regulated.
Getting insufficient quality deep and REM sleep can hinder the muscle rebuilding process.
Sleep Deprivation and Muscle Atrophy
Not getting enough sleep has also been linked to muscle atrophy (shrinkage) and impaired muscle protein synthesis.
One study tracked the effects of sleep deprivation on 16 young men over 5 days. The men were allowed just 2 hours of sleep per night. Researchers observed significant decreases in their testosterone levels and muscle protein synthesis, as well as increased muscle atrophy.
Researchers concluded sleep debt has a detrimental impact on anabolic hormonal responses and muscle protein synthesis, even in young, physically fit men.
Studies on Sleep and Muscle Mass
Here is an overview of some other scientific research examining sleep and muscle growth:
- A study in the Clinical Journal of Sport Medicine found that NCAA basketball players gained more lean mass and strength during 5 weeks of extended sleep compared to normal sleep.
- Research published in SLEEP reports a strong correlation between sleep quality and muscle mass and strength in a group of collegiate football players.
- A study in the International Journal of Sports Physiology and Performance saw rugby players complete two weeks of reduced sleep (under 6 hours per night). Participants had significantly reduced testosterone levels, muscle recovery, and neuromuscular function.
Overall, the research clearly demonstrates that inadequate sleep negatively affects muscle and strength gains. But how little is too little when it comes to building muscle?
Is 7 Hours of Sleep Enough to Build Muscle?
For most adults, getting 7 hours of sleep per night is better than 6 or fewer hours. However, it still may not be optimal for supporting muscle growth and recovery, especially if you are training intensely.
Aim for 7 to 9 hours of high-quality sleep on a regular basis to feel well-rested and see the best muscle building results. Here are some tips that can help you achieve more deep sleep:
- Be consistent with your sleep schedule, even on weekends.
- Limit screen use before bedtime.
- Create a cool, dark, quiet sleep environment.
- Avoid stimulants like caffeine late in the day.
- Consider supplements that promote sleep, like melatonin or magnesium.
- Rule out sleep disorders like sleep apnea if poor sleep persists.
Signs You May Need More Sleep
Here are some signs and symptoms that you should be getting more shuteye to properly support muscle gains:
- Need an alarm to wake up in the mornings
- Require long naps, especially after exercise
- Dozing off during sedentary tasks
- Feeling irritable and having mood swings
- Lack of motivation to work out
- Excessive soreness after training
- Increased illness frequency
- Constantly feeling fatigued
- Plateau in strength or muscle mass
The Effect of Sleep on Exercise Performance
In addition to reducing muscle growth and impeding recovery, inadequate sleep can also hinder your gym performance. Research shows that restricted sleep negatively impacts:
- Exercise capacity
- Sports-specific performance
- Cognitive function and reaction time
- Motivation and perceived exertion
This means you’ll have a much harder time completing your workouts or lifting your heaviest weights if you are chronically sleep deprived. Give your body the rest it requires to perform at its best.
Sleep Needs for Athletes and Active People
Being physically active requires more sleep than average. Athletes and people who train intensely should aim for:
- 8-10 hours per night for adults
- 9-10 hours per night for teens
For example, a study published in Clocks & Sleep saw a group of college basketball players extend their sleep to 10 hours per night for 5-7 weeks. They demonstrated improved sprint times, reaction time, free throws, and 3-point field goals.
Napping to Support Muscle Growth
Napping during the day may be beneficial for muscle building in those who do intense weight training. Some research shows that naps can support muscle protein synthesis when paired with proper nighttime sleep.
One study in Medicine & Science in Sports & Exercise examined young men who did resistance training at night followed by either no nap or a 1-2 hour nap the next day. Muscle protein synthesis was significantly increased in the nap condition compared to no nap.
Limiting naps to 30 minutes prevents excessive daytime sleepiness. Longer naps may interfere with nighttime sleep quality if taken too late in the day.
Sleep Extension for Muscle Growth
Some studies have looked at extending nighttime sleep beyond the normal 7-8 hours. When given the opportunity for extra sleep, participants experienced increases in athletic performance and muscle.
For example, a study in the European Journal of Applied Physiology saw a group of recreational athletes improve their sprint time, reaction time, and self-rated vigor after two weeks of 10 hours in bed per night.
Trying a short sleep extension trial of 9-10 hours per night can help determine if more sleep may boost your gains. This strategy should be paired with appropriate nutrition and training to optimize muscle growth.
Ideal Sleep Range for Muscle Growth
Based on the research, the ideal sleep range for muscle hypertrophy is:
- 7-9 hours per night for general muscle building.
- 9-10 hours per night for dedicated athletes and bodybuilders.
Aim for your minimum sleep target each night, allowing for flexibility based on individual needs. Getting lower amounts occasionally is fine, but chronic restriction can impede gains.
Connect Sleep and Nutrition for Muscle Growth
Along with proper sleep, paying close attention to nutrition can maximize your muscle building results. Some strategies include:
- Eat sufficient calories in a slight surplus to aid growth.
- Prioritize protein intake to provide amino acids for muscle protein synthesis.
- Time nutrient intake around exercise to optimize recovery.
- Avoid drastic cuts that lead to lean tissue loss.
- Supplement with creatine, beta-alanine, etc.
Sleep and nutrition work closely together to fuel gains. Lacking in either area can short circuit results.
The Role of Cardio and Sleep for Muscle
Including some cardiovascular exercise in your training is important for muscle building. Benefits of cardio include:
- Enhances recovery between intense lifting days.
- Keeps excess body fat in check.
- Improves conditioning to sustain strength training.
- Boosts blood flow to deliver nutrients.
However, excessively long or intense cardio can negatively affect strength and muscle goals. Make sure you get enough rest and sleep to avoid overtraining.
Other Lifestyle Factors Impacting Muscle and Sleep
Some other lifestyle factors that can influence both sleep and muscle growth include:
- Stress management: High stress impairs sleep and elevates muscle-wasting stress hormones like cortisol.
- Substance use: Alcohol, marijuana, and other substances can interfere with deep sleep cycles and testosterone production.
- Hydration: Dehydration from sweating during workouts can disturb sleep. Drink enough fluids throughout the day.
- Travel: Frequent time zone changes from traveling can disrupt circadian rhythms and sleep-wake cycles.
Optimizing these areas promotes quality sleep and prime muscle building capacity.
While adults require 7-9 hours of sleep per night on average, hitting the bare minimum end of that range may not suffice for dedicated gym goers and athletes.
Muscle growth and repair processes occur predominantly during sleep. Getting adequate deep and REM sleep is critical for optimal recovery and release of anabolic hormones.
Chronic sleep restriction can reduce muscle protein synthesis, increase protein breakdown, lower key hormones, and impede strength and endurance.
For most, focusing on 7-9 hours nightly allows for sufficient muscle building sleep. Athletes and serious trainees benefit from aiming for a minimum of 9-10 hours. This can be complemented by brief, strategic napping.
While individual needs vary, prioritizing quality sleep is a research-backed way to boost muscle hypertrophy results when combined with proper nutrition and exercise.