How Important is Sleep?
Sleep isn't just a luxury; it's a cornerstone of health, recommended by the American National Sleep Foundation to last 7-9 hours per night for adults. While many athletes focus on stretching or nutrition for recovery, sleep is often forgotten. Studies show that less than 8 hours of sleep increases the risk of injury by 1.7 times. Consistently short sleep can impact recovery and increase the risk of fatigue-related injuries. Beyond sleep hours, the quality of your sleep is equally crucial. If you're dieting or trying to lose weight, compromising on sleep can dramatically reduce fat loss while increasing the loss of lean mass (muscle and bone mass).
What Does Sleep Actually Do?
During sleep, our bodies are busy at work:
- Restoring immune and endocrine functions
- Revitalising the nervous system
- Enhancing memory and learning capabilities
The Cost of Sleep Deprivation:
Skipping sleep can lead to:
- Diminished performance and increased perceived effort of workouts
- Slower recovery and decreased growth hormone release
- Impaired cognitive functions including memory, decision-making, and skill acquisition
- Fluctuations in hormones like testosterone and increased hunger due to higher ghrelin levels.
Sleep and Weight Loss
Research by Nedeltcheva et al. (2010) highlights the significant impact of sleep on weight loss efforts. In the study, participants with only 5.5 hours of sleep lost 55% less fat and 60% more lean body mass than those who slept for 8.5 hours. Notably, the sleep-deprived group felt hungrier, likely due to elevated levels of the hunger hormone ghrelin. If you're dieting, proper sleep is vital for maximising fat loss, minimising lean mass loss, and maintaining a higher resting metabolic rate.
Sleep Deprivation and Hormone Regulation
For men, less than 5 hours of sleep can lower your testosterone levels by 10-15%, particularly affecting your peak hours from 2pm to 10pm. This drop can lead to loss of muscle mass, mood changes, and problems with sexual function. For women, chronic lack of sleep throws off hormonal balance, raising stress hormones like cortisol and lowering key hormones like oestrogen and testosterone. These imbalances worsen fatigue and affect mood and focus, taking a toll on overall health and performance.
Sleep is more than just rest; it's a powerful enhancer of your physical, cognitive, and metabolic functions. Make it a non-negotiable part of your health regimen to ensure you get the most out of your training and nutrition.
References:
Wild, A. (n.d.). Your body bible: Pro edition. Wild Physio Fitness. Retrieved from https://wildphysiofitness.au/products/your-body-bible-ebook-pro-edition
Bunn, J., & Easley, D. (2024). Chronic sleep loss and hormonal dysfunctions in female athletes. Digital Commons of Western Kentucky University. Retrieved from https://digitalcommons.wku.edu/icsksrw/2024/Keynotes/5/
Nedeltcheva, A. V., Kilkus, J. M., Imperial, J., Schoeller, D. A., & Penev, P. D. (2010). Insufficient sleep undermines dietary efforts to reduce adiposity. Annals of internal medicine, 153(7), 435–441. https://doi.org/10.7326/0003-4819-153-7-201010050-00006
image source: https://www.pexels.com/photo/photo-of-person-holding-alarm-clock-1028741/
