The Crucial Role of Sleep
in Achieving Optimal Health

People will go to great lengths to ensure they have a smart and well structured exercise program, nutritional plan and supplementation regimen, yet they often forget about their sleep and sleep quality. Sleep is absolutely essential to survival and good health. 

Think about this – you can go through life eating pretty poorly and still live around 75 years – but if you don’t sleep, you won’t live much longer than a week. About 1 in 3 adults (and even more adolescents) don’t get enough sleep, which makes them more likely to have health problems like obesity, diabetes, heart disease, stroke, dementia, and cancer. They are also more likely to have trouble focusing at work/school. In addition, about 100,000 motor vehicle crashes every year in the United States are related to drowsy driving. Most adults also likely overestimate how much sleep they are actually getting, due to poor quality sleep. Let’s dive more into some of the benefits of getting a proper night’s sleep, and how sleep deprivation can affect your workouts, body composition, mood, and more. 

Workout Enhancement

Sleep gives the body time to recover, conserve energy, and repair and build up the muscles worked during exercise. When we are hitting our sleep goals, the body produces growth hormones. As children and adolescents, we need these growth hormones in order to grow into healthy adults. As adults, these growth hormones help us build lean muscle and help our body repair and recover from a hard workout. 

Five stages occur during sleep. Light sleep occurs during stages one and two, with deeper sleep occurring during stages three and four. Rapid-eye movement (REM) sleep occurs in stage five. Growth Hormone (GH) is secreted during stages three and four. If you are not achieving complete sleep cycles, GH secretion will diminish and influence your body’s recovery. A lower GH secretion will lead to a drop-off in exercise performance. 

Body Composition and Hormones

Studies show that adults who consistently sleep fewer than 7 hours each night are significantly more likely to be obese. In addition to this, the study also found that staying awake beyond midnight seemed to increase the likelihood of obesity. These associations depended on the dose, with the data showing later bedtimes and shorter sleeping hours result in greater levels of body fat gain. Wake-up time itself was not found to be associated with weight gain or rates of obesity. In children and infants, studies have shown that children who do not get sufficient sleep are more likely to be obese before the age of 10.

As far as hormones go, sleep deprivation has a pretty substantial effect on your appetite hormones. A study done on men showed that just two nights in a row of sleep deprivation (4-hour sleep nights) resulted in lower levels of leptin and higher levels of ghrelin. Leptin functions to inhibit hunger and regulate your body’s balance between food intake and energy expenditure. Ghrelin is the hunger hormone, it is released by the stomach when the stomach is empty and ready for food. You can see how a lower leptin level and a higher ghrelin level can contribute to weight gain. The men in the study reported higher overall hunger and more cravings for sweets. 

High concentrations of cortisol – a stress hormone – can positively or negatively affect sleep quality. One of cortisol’s main functions is to regulate how your body responds to stress. Essentially, when you experience stress, the adrenal glands release cortisol into the body which increases your blood sugar, giving you the energy boost you need to perform better during the stressful situation. Cortisol has other functions, including metabolism regulation through blood sugar regulation, maintaining blood pressure, reducing inflammation, and supporting the immune system. Cortisol and melatonin work together to make sure you are awake in the morning and ready for bed at night; however, sometimes things can go awry. Under normal circumstances, cortisol is highest in the morning when you wake up, and drops off gradually as the day goes by; melatonin follows an opposite pattern – it peaks while you are asleep, drops off in the morning, and starts its climb again in the evening. Under prolonged periods of stress, cortisol will remain elevated throughout the day, as opposed to dropping off in the morning like it should. An abnormally high level of cortisol at night will negatively affect your sleep.

Cat Sleeping in Bed under the covers

Some Tips for a Better Night’s Sleep

Making sleep a priority is very important for your overall health and wellbeing. Here are some tips for keeping your sleep environment beneficial to you:

  1. Consistency: Keeping a relatively consistent bedtime and wake time will help regulate your melatonin and cortisol levels.
  2. Light: Keep your bedroom extremely dark, to tell your body’s clock that it is time for sleep.
  3. Relaxation/Routine: Develop a pre-bedtime routine that is relaxing and familiar. Remember that screens/technology will disrupt your sleep.
  4. Temperature: Keep a slightly cool temperature in the room, between 66-72 degrees fahrenheit (around 67 is ideal).
  5. Stimulants: Eliminate stimulants like caffeine/nicotine, especially later in the day.
  6. Exercise: Exercising regularly will help improve your sleep habits. Just be careful not to exercise too close to bedtime, because it is stimulating.
  7. Fullness: Eating a dinner that makes you overly full can disturb your sleep, as well as eating too close to bedtime. 
  8. Supplements: There are a handful of supplements that can improve your sleep habits:
    • Phosphatidylserine (PS) is effective in cortisol regulation/suppression and can help to control evening cortisol levels, leading to better sleep quality. 
    • Magnesium Bisglycinate – low levels of melatonin are associated with low levels of magnesium. Magnesium is involved in more than 600 enzymatic reactions, supporting restful sleep, muscle relaxation, heart health, bone health, and nerve health.
    • Thorne has a Sleep Bundle that is a trio of bedtime supplements: magnesium bisglycinate, pharmaGABA-250, and melatonin. PharmaGABA-250 is a brain calming neurotransmitter.


In conclusion, the benefits of sleep extend far beyond merely feeling rested. They affect every aspect of our health: our physical, mental, and emotional well-being, influencing workout performance, body composition, mood, hormonal balance, and more. As you embark on your fitness journey, consider sleep not just as a necessity but as a powerful ally in achieving your goals.