Simple Things - Sleep: The Forgotten Recovery Method Part 1

Recently I've been having trouble sleeping...

Slightly embarrassing... But gets the point across

Everyones had it, those nights when you've had your bath, sipped away your warm milk or Horlicks, got yourself all nicely tucked up into a clean bed and started counting sheep... But realised once you've number crunched enough sheep to fill Wales and New Zealand, its just not going to happen for you. Well during one of these nights, I did some research and found some really interesting stuff out about the effects that limited or low-quality sleep has on performance and recovery.

I decided to start off with something fairly easy-going and up beat and build my way up (didn't want to drop off whilst researching now did I...), so I took a look at a couple of articles on Dr. Marco Cardinale's blog. I really like the infographics that Dr. Cardinale puts out there, they're simple, thought provoking and the one he's publicised on this topic was particularly intriguing, take a look;

http://marcocardinale.blogspot.co.uk/2012/07/sleepless-night-infographics.html

Now, I know its not written with a specific focus on sports performance, but I wanted to draw attention to a couple of the dramatic points made and look at them in more detail with regards to training and performance.

1. Driving on less than 5 hours sleep is like driving with a Blood Alcohol Content of 0.05g.

Before I discuss this further in order to put it into context I think it's important to be aware that the UK drink driving limit is 0.08g/100ml of blood. This means driving on less that 5 hours sleep can be compared to a 100kg rugby player having a shot of tequila before jumping into the car. Now, I've dramatised that a bit, I'm not going to lie, initially I found it difficult to believe that this was true. But after looking into the effects of sleep deprivation on cognitive function I found that in comparative studies between the sleep deprived and alcohol intoxicated, a BAC of 0.05g was the lowest figure I could find! One unnerving study found that in groups of truck drivers, 28 hours sleep deprivation caused similar dips in cognitive function (measured through an assessment of their ability to stay in lanes) as having a BAC of 0.1g! Although it did explain a couple of things...

On a serious, simple, sporting note... If you compete in a sport that requires decision-making, quick reactions, auditory or visual accuracy, logical reasoning or memory then these types of drop in cognitive function can be devastating to performance. And if nothing else, these findings should highlight the attaining an appropriate amount of sleep is key in order to perform maximally. If you compete in a sport that doesn't involve any of these things you can have as many late nights and early starts as you'd like, but I'd be interested to hear what sport it is and whether or a feeling of Dutch courage is an asset!

2. Lack of sleep lowers testosterone levels on average by 10-15%.

I almost felt the sudden silence and horrified gasps from all you Alphas out there when reading that statement! - "Drop in Testosterone, I'll spend all day in bed" - "I'll spend two..." - Now I appreciate, I've pulled these numbers and statistics from something akin to a glorified cartoon referencing websites. But after tracking down the original research articles these claims are based on, and reading around similar studies, I was blown away by their findings. Putting aside the fact that lack of sleep does seem to cause a drop in daytime serum testosterone levels by a magnitude of around 1/10th for a second, its also been shown that lack of sleep has the potential likelihood of increasing evening serum cortisol, whilst decreasing the rate of glucose clearance by something in the region of 1/3rd in a healthy, sleep deprived populous. These studies weren't conducted on athletic populations, but the impact these changes could have on performance development are large, not to mention their effect on libido! Even looking from a very basic perspective it's clear to see the effect of decreased testosterone or increased resistance to insulin, two highly anabolic substances, coupled with increased levels of cortisol, a highly catabolic hormone, are likely to clear an put the body at greater risk of atrophy. There may be a handful of situations where this might be desirable in sport, but not many... If consistent over time, this could contribute to decreases in lean muscle mass and lead to a decrease in the performers ability to generate force, but at the very least would limit the gains made through training. And the last thing any athlete or coach wants is to see development plateau due to burning the candle at both ends.

3. Sleeping an average of less than 6 hours increases lifetime heart-attack risk by 50%.

Just a short note on this point, as it's a chilling statistic supported by information from World Health Organisation on the benefits of physical activity on health... The implications, that a lack of sleep can have serves as a reminder that although the battle for performance development is always raging, simple things like not getting enough sleep can have much wider implications than just negative effects on performance on the field, court, or battlefield.

At the end of the day, you could complete the perfect, complicated as hell training program individually tailored to your needs, monitor and evaluate training loads down to the gram or millilitre per minute, take all the recommended cocktail of after exercise supplements, and eat the holy-grail of perfectly balanced diets (not necessarily in that order), but without sufficient sleep you won't have the foundation to build these factors on. It's simple, when you're playing the game of inches, with all of those little 1% improvements up for grabs around you, facilitating effective recovery and preparation through sleep (something you have much more control over than the factors above) has to be close to the top of the list of things to get right.

If you're interested in taking a deeper look into the effects changes in  sleep patterns has on performance, take a look at these sources and sites for more information;

Dr. Marco Cardinale's Blog - http://marcocardinale.blogspot.co.uk/

DURMER, Jeffery and DINGES, David. (2005). Neurocognitive Consequences of Sleep Deprivation. Seminars in Neurology, 25 (1), 117 - 129.

LEPROULT, Rachel and VAN CAUTER, Eve. (2011). Effect of 1-week of Sleep Restriction on Testosterone Levels in Young Men. The Journal of the American Medical Association, 305 (21), 2173 - 2174.

SPEIGEL, Karine., LEPROULT, Rachel. and VAN CUATER, Eve. (1999). Impact of Sleep Debt on Metabolic and Endocrine Function. The Lancet, 354 (9188), 1435 - 1439.

And in the end, half way through writing these references during my late night research session I nodded off. Funny that...

If you enjoyed this post, keep an eye out for Part 2 of this article, looking at methods to improve sleep quality. Don't miss out! Simply sign up for email notifications to be kept up to date with all new posts and information that become available, as well as follow me on Twitter @GaryHuttAD

Yours in Strength,

Gary