The fact that sleep is important is nothing new, but do we really know why is that so and what does scientists and researchers have to say about it. Read below to understand the importance of sleep and what are the steps that you could take to improve your quality of sleep.

Before we get into the topic lets understand what Sleep Deprivation means. According to American Academy of Sleep Medicine :-

Sleep deprivation occurs when an individual fails to get enough sleep. The amount of sleep that a person needs varies from one person to another, but on average most adults need about seven to eight hours of sleep each night to feel alert and well rested. Teens need an average of about nine hours of sleep per night, and children need nine hours of nightly sleep or more, depending on their age.

Now that we have a little understanding of Sleep Deprivation, let’s see what science has to say on the effects of it on our workout and nutrition.

Sleep Deprivation and it’s impact on Cognitive and Neurological Functions

Multiple research show that when sleep deprived the body tends to give up when it would otherwise normally be physically capable of pushing further (3). Furthermore researchers have proven that sleep Deprivation causes lack of Cognitive Functions and increases your chances of Mistakes (1,2). With increased chances of mistakes, you increase chances of injury. 

Reduced Sleep and Fat gain

A 2010 study done by Nedeltcheva AV and colleagues shows that the test subjects in group B that slept for 8.5 hours even though lost the same amount of weight as the second group A that slept for 5.5 hours but group A preserved more muscle mass during their diet phase compared to group B(4).

Other than just preserving more muscle mass, lack of quality sleep leads to increased Ghrelin levels and Reduced Leptin which increases hunger and leads to weight gain (6).

Impact of Sleep Deprivation on Muscle Growth

In a study on the effects of sleep deprivation and cortisol secretion the results showed a reduced cortisol secretion during sleep (7). Cortisol being a Catabolic hormone, is not what you’d want in high amounts.

Sleep deprivation causes a reduction in testosterone levels as well, In fact, a 2015 paper found that:

Day-to-day testosterone levels were significantly decreased by 10 to 15% in young men who underwent just 1 week of sleep restriction to 5 hours per night (10).

Not just the quantity but the quality of sleeps also governs your muscle growth too. Sleeping during the day rather than the usual Night hours can cause an increase in cortisol and reduction in testosterone (9).

Now that we know how important sleep is to reach our fitness goals, the question arises on what should I do to get a better sleep. We have mentioned some of the recommendations AASM(American Academy of Sleep Medicine) :-

    1.  At least 7 Hours of sleep at night.
    2.  Make environment sleep friendly. Hygienic and  Dark room, with less disruptive noise as possible would promote better quality of sleep
    3.  Keep Bedroom at a cooler temperature that suits you
    4.  Exercise Regularly
    5.  Avoid Heavy and spicy meals before bed.
    6.  Avoid stimulants before bed

References :- 
  1. Alhola, P., & Polo-Kantola, P. (2007). Sleep deprivation: Impact on cognitive performance. Neuropsychiatric Disease and Treatment, 3(5), 553–567.,
  2. Jeffrey S. Durmer1, David F. Dinges2,Neurocognitive Consequences of Sleep Deprivation

3. Van Helder, T., Radomski, M.W. Sleep Deprivation and the Effect on Exercise Performance. Sports Medicine 7, 235–247 (1989).

4. Nedeltcheva AV, Kilkus JM, Imperial J, Schoeller DA, Penev PD. Insufficient sleep undermines dietary efforts to reduce adiposityAnn Intern Med. 2010;153(7):435–441. doi:10.7326/0003-4819-153-7-201010050-00006

5. S. R. Patel Reduced sleep as an obesity risk factor

6. Taheri S, Lin L, Austin D, Young T, Mignot E (2004) Short sleep duration is associated with reduced leptin, elevated ghrelin, and increased body mass index. PLoS Med 1(3): e62.

7. ELLIOT D. WEITZMAN, JANET C. ZIMMERMAN, CHARLES A. CZEISLER, JOSEPH RONDA, Cortisol Secretion Is Inhibited during Sleep in Normal Man, The Journal of Clinical Endocrinology & Metabolism, Volume 56, Issue 2, 1 February 1983, Pages 352–358, 

8. Gambineri, A., Pelusi, C. & Pasquali, R. Testosterone levels in obese male patients with obstructive sleep apnea syndrome: Relation to oxygen desaturation, body weight, fat distribution and the metabolic parameters. J Endocrinol Invest 26, 493–498 (2003).

9. Rafael Luboshitzky, Ziva Zabari, Zilla Shen-Orr, Paula Herer, Peretz Lavie, Disruption of the Nocturnal Testosterone Rhythm by Sleep Fragmentation in Normal Men, The Journal of Clinical Endocrinology & Metabolism, Volume 86, Issue 3, 1 March 2001, Pages 1134–1139, 

10.  Leproult R, Van Cauter E. Effect of 1 week of sleep restriction on testosterone levels in young healthy menJAMA. 2011;305(21):2173–2174. doi:10.1001/jama.2011.710

11.  Kitsaras G, Goodwin M, Allan J, Kelly MP, Pretty IA. Bedtime routines child wellbeing & development. BMC Public Health. 2018;18(1):386. Published 2018 Mar 21. doi:10.1186/s12889-018-5290-3