Sleep is crucial. It’s one of Maslow’s hierarchy of needs, ranked at the base of the hierarchy and a critical biological component for human survival. Alongside shelter, food, and water, sleep is considered essential for our daily functions. As the ways that we work and live evolve, sleep has started to take a backseat to social media, late-night shifts, socializing at the bar, and more. Ultimately, this has caused a significant impact on public health.
What about strength? Increased exercise performance and success in the gym is tied to a lot of things, but sleep is one of the main building blocks of a well-rounded athlete. Unfortunately, too few adults are getting the sleep that they need, and that’s being reflected in how we train.
Let’s dig into what sleep debt is, how it affects us, how it affects our training, and what we can do to improve our sleep health overall.
Why is sleep so important?
Sleep has our brain cycling through repeating periods, alternating between two distinct modes: REM and non-REM sleep. During sleep, the body is an anabolic state and gradually restoring the skeletal, muscular, immune, and nervous systems. As a whole, sleep helps us to process the things we learned over the day, removes toxins built up in our brain as we’re awake, and prepares us for the next day.
Sleep is also critical to recovery when we train.
Sleep is when muscle growth occurs. You may have heard that rest days are when your muscles grow, which is partly true, but the bulk of the biological work that is needed to repair your muscles and grow stronger happens majorly when you’re asleep. Those micro-damages you caused to your muscle tissue are flooded with chemicals while you sleep – chemicals called “reactive oxygen species.” The inflammatory response kicks in, at what point your body initiates a response to remove damaged cells/tissues, reduce inflammation, and begin the process of repair and replacement. With the constant stress of training, muscles grow – and that growth happens when you sleep.
Sleep is also critical in your recovery if you are injured. Whether it’s a simple muscle strain to a bone injury, deeper stages of sleep will promote blood flow, which then brings along additional nutrients and oxygen to promote the recovery and repairing of muscles and regenerates cells. Your pituitary gland also releases growth hormones while you sleep, which can aid in muscle repair and growth. Finally, prolactin, which regulates inflammation, is also released when sleeping. If you lack sleep, you’re more likely to experience body inflammation. This can make injury recovery take longer and risk further injury during a time of healing.
What is sleep debt?
Sleep debt is essentially the difference between the sleep you need and the sleep that you’re getting. If you sleep 5 hours a night and you need 8 according to your age category, you have a sleep debt of 3 hours. If you sleep 4 hours the next night, now you have a sleep debt of 7 hours. Because sleep debt is cumulative, it adds up over time and can begin to negatively impact your health.
A recent study showed that 1 in 4 adults aged 18-34 and 1 in 3 adults aged 35-64 are not getting enough sleep. Over half of adults have difficulties going to sleep or staying asleep, and about a fifth of adults do not find their sleep refreshing.
Cumulative sleep debt overtime can result in:
- Increased sedentary time when awake
- Chronic stress
- Poor mental health
- Weakened immune system
- Poor physical performance
- Lack of efficiency and focus during the day
- Lack of learning capabilities
What’s even more alarming is that cumulative sleep debt can put otherwise healthy adults at higher risk of the following conditions:
- Heart disease
- Hypertension
- Diabetes mellitus
- Obesity
- Cardiovascular disease
Research has shown that even if you don’t feel tired all the time, you could still very well be impacted by sleep debt. See, your body is great at adapting to stressors and trying to readjust to its preferred homeostasis, so it might make you feel as though you aren’t sleepy at all. But in the background, you’ll still be suffering from significant declines in both your physical and mental performance.
As you can see, the consequences of sleep debt are very real. With some occupations and roles, sleep debt can be very difficult to avoid. This is especially true for shift workers, new parents, and caregivers.
How does sleep quality affect exercise performance?
Good quality sleep has been associated with greater muscle strength/exercise performance. This is, in part, due to the recovery portion we’d mention previously, but it’s also great for cognitive function. Increased cognitive function helps you think better, retain things better and, yes, remember those very specific cues your coach gave you the last time you tried a new movement.
Inadequate sleep has also been associated with adverse metabolic health outcomes. For those of us training on inadequate sleep, the actual impacts and benefits of resistance exercise and training is significantly reduced – therefore limiting our capabilities.
Have you ever tried to train on too few hours of sleep? It’s pretty tough to pull yourself out of bed and head to the gym. Besides the actual motivational factor, there’s real research behind the consequences of inadequate sleep and exercise performance. So, if you want to start seeing improvements and effective performance, get your recommended 7-9 hours of sleep!
How do we improve our sleep health?
For those of us who have become chronically sleep deprived, it’s very difficult to re-adjust and get back to a healthy sleep schedule. It isn’t going to happen overnight, but to avoid the consequences of sleep debt, it’s important to learn how to improve your sleep hygiene and how much sleep you need.
Here are some tips.
Figure out how much sleep you need. This varies from person to person, but typically ages 20-60 need about 7-9 hours a night, where teenagers might need 8-10. Within those ranges, everyone benefits from a different amount. You might feel best with 7 hours, but your partner might need all 9. It varies.
Follow a set bedtime routine. Try to go to bed and wake up at the same time each day. If you start to feel sleepy at a specific time, listen to your body and adhere to those times. If you need to set an alarm in the morning to ensure you wake up at a specific time, do that! You might be able to adjust to a point where you no longer need an alarm.
Exercise. Whatever you do for your training, exercise can promote healthy sleep. Remember that overtraining can worsen your sleep quality as well, so make sure you aren’t doing too much. Also note that the times of day when you train can impact your sleep, so figure out what works best for you with some trial and error.
Avoid caffeine too late in the day. Caffeine is a great tool for training and an everyday routine for some people but having it too late in the day can affect your sleep. Even if you’re still able to sleep with caffeine in your system, there’s no telling if that sleep is restorative or not.
Keep an optimal bedroom environment. Keep the temperature a little below room temp, replace any uncomfortable sheets or pillows, and remove all sources of distraction (including electronics!)
Sleep debt has started to impact our entire population, but it doesn’t have to be what holds you back in your training – or your life. With a few small adjustments and attention to your sleep hygiene, you can get back on track and slowly start to chip away at that sleep debt. Your body will thank you!