In one of my recent blogs, I wrote about the importance of rest and recovery and how this can help improve your performance (stress + rest = growth - illustrated in the book Peak Performance; do yourself a favour and read this book). One of the best, and most under-rated, ways to attain this is by attaining quality sleep.
In today’s world we succumb to staying up much later than expected to meet deadlines, scrolling through our Facebook feeds, watching “one” more episode (which turns into multiple) of your Netflix series, etc. But by repeatedly missing out on quality sleep, we are doing more damage to our body than we may realise. It is important to get the right amount of rest every night and maximise the benefits that can arise from sleep.
There are recommendations that have been established per age brackets (in the table below). However, these do not account for the amount of physical activity one completes in a day/week. Because of this, I recommend runners/readers who consistently place themselves under a lot of stress (e.g. running at least more than 30mins/day) to have more hours of sleep under their designated age bracket.
Guidelines taken from Hirshkowitz et. al, 2015
The hormones that set us up for adaptations:
One of the major reasons why we sleep is not only to turn our brains off, but provide us with hormones and chemicals necessary to aid your muscles (including your brain) in the recovery process. Growth Hormone (GH) is a major example of this, and relevant to runners, powerlifters, all athletes alike. GH, simply put, helps us grow and advance our athletic abilities on the track, predominantly released when sleeping by our pituitary glands.
Many athletes have been caught in the past using GH in their quest to become number one, or maintain that position. Lance Armstrong is one example (even though he was using EPO [and probably other banned substances] as well throughout his Tour de France career).
Load, intensity, duration and type of endurance exercise will influence the levels of Exercise-Induced Growth Hormone (EIGH) that is released when sleeping (Godfrey, Madgwick & Whyte, 2003). This doesn't mean that you can go hard for all of your runs just because your pituitary gland will release more GH. There are other key systems in the rest/recovery process that will influence your recovery time (regardless if awake/asleep), and can potentially be responsible for injury if you consistently go hard in every training session.
GH is just one example of the hormones/chemicals released. Our inflammatory process can also kick in whilst asleep, which also helps our muscles grow and adapt to changes we experience in exercise (Mullington, Simpson, Meier-Ewert & Haack, M 2010). I am not going to do into a whole lot of detail as to why, as the science can be quite complicated, and I do not intend on writing an essay about the whole process after we exercise.
The important point here is that sleep helps us get to the next level in our performance, and the only things it requires are reasonable quantity and good quality.
Finding out how much sleep you actually need:
How much sleep you need will depend on a few factors, and they all intertwine with each other. These include:
Age - The younger you are, the more hours you’ll need to sleep, as per the table shown above. However, that doesn’t mean you go from 10 hours of sleep whilst in high school, to averaging 5 hours through university, for example. Slowly reduce the number of hours you are sleeping per day if you plan to reduce your hours of sleep, whilst keeping in mind the guidelines that have been established by sleep and medical professionals.
Amount of activity - just like when marathon runners take up to 2 weeks off training after competition, the more you do in a day, the more you’ll need to sleep. If you have a full day from 6am-8pm (including training, work, driving, anything that requires your attention and focus), then you’ll most likely need to rest up a bit more than you think. The amount of activity we really do in a day is most likely one the most underrated aspect of our lives, as we think that some parts of our daily routine simply are not classified as being stressful.
Intensity - this mixes in with the point I just made. If you are going at 100% from dawn till dusk, then there is no need to be trying to do extra work before going to bed. Let it be tomorrow’s problem, give your brain the rest it deserves (even if you think that it doesn’t need a whole lot of it). But this doesn’t mean that if you have a few days off you can average a whole lot of less sleep over the coming days. Remember, try to do everything in moderation.
Quality is just as important as quantity:
Now that you have a rough idea on how many hours of sleep you should be aiming to attain, and how it's impacted by your activity, I think it's important to understand having quality sleep. It's just like training, if you consistently miss the pace/s that are set for you by your coach then you aren’t going to achieve optimal performance when it comes to race day. Disturbed sleep can come from a few things. Poor dietary habits, caffeine ingestion <4 hrs prior to sleep, chronic pain, etc. (Cosio, 2015). The important thing here is that you act upon these factors to improve your sleep quality. Seek out medical advice if you need, do what you have to do to get that quality sleep.
The evidence shows that whilst GH won’t be influenced by the amount of sleep you get every night, there is data to suggest that inflammatory molecules released during sleep, which is apart of the recovery process (e.g. Interleukin-6), can remain elevated during the day (Redwine, Hauger, Gillin, & Irwin, 2000). This could potentially lead to a few consequences, the main one being fatigue (Grygiel-Górniak & Puszczewicz, 2015).
The more tired you are the worse you perform, and we all want to perform at our best whether it be on the track, on a Parkrun or that assessment/job task. So by attaining quality sleep, you’ll also be able to maximise your chances at improving your performance.
Although some of this blog was a bit science-y, I am hoping you guys understand the importance of getting the right amount of quality sleep. You’ll notice how this is part 1. The second part of this blog-series will cover strategies you can implement into your own daily living to help you get these quality hours to improve your performance, both on & off the track.
Keep up the running team,
Cosio & Lin (last updated August 2015). Disturbed Sleep: Causes and Treatments. [accessed 4/07/2020]. Retrieved from: https://www.practicalpainmanagement.com/pain/other/co-morbidities/disturbed-sleep-causes-treatments#:~:text=There%20are%20several%20potential%20causes,medications%2C%20and%20certain%20psychiatric%20conditions.
Hirshkowitz, M., Whiton, K., Albert, S. M., Alessi, C., Bruni, O., DonCarlos, L., ... & Neubauer, D. N. (2015). National Sleep Foundation’s sleep time duration recommendations: methodology and results summary. Sleep health, 1(1), 40-43.
Godfrey, R. J., Madgwick, Z., & Whyte, G. P. (2003). The exercise-induced growth hormone response in athletes. Sports medicine, 33(8), 599-613.
Grygiel-Górniak, B., & Puszczewicz, M. (2015). Fatigue and interleukin-6–a multi-faceted relationship. Reumatologia, 53(4), 207.
Mullington, J. M., Simpson, N. S., Meier-Ewert, H. K., & Haack, M. (2010). Sleep loss and inflammation. Best practice & research Clinical endocrinology & metabolism,24(5), 775-784.
Redwine, L., Hauger, R. L., Gillin, J. C., & Irwin, M. (2000). Effects of sleep and sleep deprivation on interleukin-6, growth hormone, cortisol, and melatonin levels in humans. The Journal of Clinical Endocrinology & Metabolism, 85(10), 3597-3603.