How does sleep optimize exercise recovery, reduce muscle soreness, and enhance performance? Wondering what the link is between exercise and sleep? We are going to expand upon our last blog because I believe it is essential for long and fruitful training.
No Rest For The Wicked
I believe in sleep so strongly that I am willing to place a bet that I technically can’t prove and would require a study beyond my current abilities, but trust me I am probably right. Let’s take two identical individuals (genetic clones perhaps) and give them identical training programs, and identical nutrition. We will allow Clone 1 all the supplements they desire: creatine, BCAA’s, Whey protein, fat burners, pre/intra/post workout supplements, caffeine and melatonin; but restrict their sleep to 5-6 hours per night. Furthermore, Clone 1 can use any and all recover modalities that they desire, ice, e-stim, cryotherapy, thera-guns, and a full arsenal of foam rollers (bumpy and smooth, soft and hard) and lacrosse balls. Clone 2, on the other hand, isn’t allowed any special supplements or recovery modalities whatsoever, but we will allow them 8-10 hours of sleep per night. I would bet my bottom dollar that after 10 weeks of strict adherence to this protocol, Clone 2 would progress leaps and bounds ahead of Clone 1. Clone 2 would have increased muscle mass, strength, cardiovascular conditioning, and improved cognitive function. Don’t believe me? Keep reading!!
The Proof is in the Pudding
David Dinges is one of, if not the leading expert in sleep research at The University of Pennsylvania. He conducted research that aimed to answer three questions:
- How long can a human go without sleep before their performance begins to suffer?
- Is that individual aware that their performance is impaired?
- How many nights of full sleep will it take for performance to recover?
In his study, Dr. Dinges had four different groups of individuals, under varying levels of sleep deprivation, press a button in response to a light stimulus for 10 minutes each day, for fourteen days. Group 1 went 72 hours straight with no sleep, group 2 was allowed 4 hours sleep each night, group 3 was allowed 6 hours sleep each night, and group 4 was allowed a full 8 hours sleep. Dr. Dinges study provided a few key results.
- 10 days of 6 hours of sleep per night was equivalent to staying up for 24 hours straight and resulted in a 400% decrease in performance (No that was not a typo!!).
- Each night of less than optimal sleep resulted in a decrease in performance, with no signs of a plateau.
- Each group that was sleep deprived severely underestimated the decrement in their performance.
- Following 3 nights of as much sleep as the participants wanted, their performance was STILL below baseline (So no, you can’t catch up on your sleep on the weekend).
A similar study by a lab in Australia took two groups of individuals; group one got drunk to the legal driving limit, group 2 was simply deprived of sleep for a single night. Both groups performed a test assessing cognitive ability and both groups did equally poorly. In other words, staying awake for 19 hours will result in the same cognitive impairment as a legally drunk driver. What is it about sleep that makes it so powerful and such an essential pillar of human performance?
Is Sleep for The Weak?
If you think about it from an evolutionary perspective, sleep is terribly disadvantageous. 3,000 years ago humans could die from SO many different things. One day you wake up and you go gather some berries near camp and you get stung by a scorpion. Boom, dead. You go for a nice walk down the Sahara with some of your tribe members and you get attacked by a saber tooth tiger. Boom, dead. When we sleep we are completely vulnerable for 8-10 hours of the day, yet it still is an essential process, why?
Most of our hormones are released in a cyclical manner, and on a gradient. Meaning that an increase in one hormone usually will result in a decrease in another. For example, our cortisol levels are at their highest point in the morning when we wake up. Levels rise gradually to suppress melatonin secretion and allow our body to wake. The opposite is true for melatonin and cortisol at night. When the sun goes down and night begins to set in, melatonin levels begin to rise and cortisol begins to fall to coax us into a pleasant night of sleep. One hormone, in particular, that is conducive to performance is testosterone. Most of the secretion occurs at night and can be depicted as such:
→ ↑Sleep→ ↑Testosterone→ ↑Muscle Protein Synthesis→ ↑Muscle mass
Increased muscle mass is often associated with increased performance, regardless of the sport or endeavor. On the other hand, if we don’t get the sleep we require, the above depiction would look more like this:
→ ↓Sleep→ ↓Testosterone→ ↓Muscle Protein Synthesis→ ↓Muscle mass
Most of this release in testosterone occurs in the hours right before we go to sleep, then peak during the deepest portion of our sleep (REM sleep). If sleep is so important, what impedes us counting sheep?
The Sleep Slayers
So what crushes our sleep? If I go to sleep at 12am and wake up at 8am, I still get my full 8 hours, right? Yes and no, not all sleep is equal, and there are three main culprits that can hinder our sleep:
- LED and electric light- Our eyes are sensitive to light across the entire visible spectrum, meaning that any light will suppress melatonin secretion, and thus sleep, to some degree. But they are especially sensitive to light in the 400-500nm wavelength. This wavelength is otherwise known as blue light. Blue light tells your brain that it is daytime and to postpone our melatonin cocktail for as long as 3 hours. LED-powered electronics and light bulbs emit light at this and can suppress melatonin secretion up to 50% while in use.
- Caffeine- Good Ol’ Joe (fun fact, as I type this I am sipping on a cup of black coffee with one Splenda and it is delicious). Caffeine is a beautiful vixen that can lift you up, or be your undoing. Caffeine works in a somewhat simple way, it inhibits receptors in your brain that indicate tiredness or sleep-pressure (our pressure to sleep). If we drink caffeine too close to bedtime, that pressure to sleep can be postponed for 8-10 hours following our last cup.
- Alcohol- Contrary to popular belief, alcohol does not help one get a good night’s sleep. Alcohol acts as a sedative and inhibits sections in our brain that provide consciousness and thought. If one person punched another and knocked them out, you wouldn’t say they fell asleep, right? You would say they are unconscious. These are two different phenomena and do not produce the same results. To put in other words, sleep involves unconsciousness, but unconsciousness does not necessarily involve sleep, but rather the absence of consciousness.
Work Hard Sleep Hard
I hope I was able to convince you that sleep is one of the best contributors to sports performance that you can utilize. If you were wondering how you can optimize your sleep and reap its benefits, check out my previous blog “How To Maximize Recovery”, where I go over ways to achieve a deeper, more restful sleep. If you have any questions, feel free to reach out!
BS Exercise Science
“Coach Jon, Irvine Strength and Conditioning Coach who is an athlete himself and someone I recommend to my patients. He knows what he is doing and his attention is on the proper form and injury prevention is what I love about him.”- Dr. Shakib
- Leproult R, Cauter EV. Effect of 1 Week of Sleep Restriction on Testosterone Levels in Young Healthy Men. PubMed 21: 2173-2174, 2015.
- Griggs RC, Kingston W, Jozefowicz RF, Herr BE, Forbes G, Halliday D. Effect of testosterone on muscle mass and muscle protein synthesis. J Appl Physiol 1: 498-503, 1989.
- Testosterone, aging, and the mind. Harvard Health Publishing. Jan 2018
- Luboshitzky R, Herer P, Levi M, Shen-Orr Z, Lavie P. Relaionship between rapid eye movement sleep and testosterone secretion in normal men. J Androl 6: 731-7, 1999.
- Walker M. Why We Sleep: Unlocking The Power of Sleep and Dreams. 1st ed., New York, 2017.