SLEEP CONSIDERATIONS FOR ATHLETES
From the perspective of a strength athlete, acute performance is particularly relevant when we look at the biological effects of sleep. We need to be able to perform in training. We know that having consecutive nights of poor sleep can impact strength endurance negatively in big compound movements e.g. our ability to sustain load across multiple sets in higher rep ranges. However, this isn’t the case with isolation style movements e.g. accessories like leg extensions, tricep pushdowns etc. Several studies have suggested that top end strength isn’t negatively impacted by this consecutive reduction in sleep, however, many of these studies weren’t done with strength sports in mind, and the tasks required of the participants were basic movements as opposed to complex movements like a high RPE 1x3 barbell squat or bench press.
Another consideration when we’re considering the impacts of sleep is injury risk. Spending time out from training, as well as injury itself can be an incredibly high hurdle to have to jump over in a training career. In this case, prevention is very much better than healing! Over time, not getting enough sleep predisposes athletes to musculoskeletal injuries - there hasn’t been enough research conducted to prove a definitive type of sleep pattern associated with increased musculoskeletal injury, but anecdotally we can say that there’s definitely a relationship there between not getting enough sleep and increased incidence of injury.
On top of taking time off for injury, the last thing we want to do is take time off training due to being unwell - especially when timing of training is key when leading into a competition. Knowing this, it’s important for us to consider the impact of sleep on immune function! Several studies have shown that individuals inoculated with a virus such as rhinovirus exhibited symptoms to a greater degree than their counterparts if they didn’t get enough sleep. This can be seen in individuals who are vaccinated too - getting adequate sleep is key for maintaining good immune function - having a better immune system will help you train more consistently as you’ll be taking less time off from being unwell.
Powerlifting is a weight class based sport - ignoring the impacts of sleep on body composition and bodyweight would leave a fairly large stone unturned. For example, people who have had insufficient sleep are likely to eat on average 250 kcal more a day than their well rested counterparts. Lack of sleep doesn’t necessarily impact energy output in the short term e.g. the next day, but it can impact the balance of our hunger hormones. Saying that, there are very few studies out there that have looked directly at the relationship between sleep and body composition. The current research isn’t very clear on the impact of restricted sleep on our hunger hormones, there looks to be a potential for it to change the ratios between leptin and ghrelin rather than being the cause for absolute increases or decreases in either. However, several studies have observed a general response in people experiencing sleep restriction - there is a general increase in sympathetic activity in their nervous system. Once consequence of this is increased gluconeogenesis and glycogenolysis - if this process is left unopposed it can contribute to hypoglycemia and in turn contribute towards insulin resistance. The net result here is systemic insulin resistance. On top of our physical health, sleep is vital for our mental health and cognition. Pretty much all aspects of cognition and mood drop when we experience restricted sleep i.e. going to bed too late and waking up early for consecutive days. Over time if we experience poor sleep quantity and quality it can contribute towards mood disorders and conditions like depression which bring about their own challenges.
SLEEP QUALITY
When we’re talking about sleep health, we’re not only talking about getting enough sleep - it’s an important dimension of sleep health, however, there are several other important dimensions to consider e.g. sleep timing - is sleep occurring at a time of day where your body isn’t primed for sleep? If so, the amount of sleep you get and the quality of the sleep you get will likely be compromised.
There are several subdivisions to sleep quality:
Sleep Duration:
The total amount of time spent sleeping each night is a fundamental aspect of sleep quality. Both insufficient and excessive sleep durations can impact our overall well-being.
Sleep Continuity:
This refers to the uninterrupted and smooth progression through the different sleep cycles. Factors like waking up frequently during the night or experiencing disruptions can affect sleep continuity.
Sleep Onset Latency:
The time it takes to fall asleep after getting into bed. A prolonged latency period suggests difficulties in initiating sleep.
Sleep Efficiency:
Sleep efficiency is the ratio of time spent asleep to the total time spent in bed. Higher sleep efficiency indicates a more consolidated and effective sleep.
Sleep Architecture:
This involves the structure and organisation of sleep cycles, including the distribution of REM (rapid eye movement) and non-REM sleep stages. Each sleep stage plays a unique role in the overall restorative process of sleep.
Wake After Sleep Onset (WASO):
WASO represents the total time spent awake during the night after initially falling asleep. Elevated WASO can be indicative of sleep disturbances.
Number of Awakenings:
The frequency of waking up during the night is another aspect to consider. Excessive awakenings may affect sleep continuity.
Daytime Sleepiness and Fatigue:
Assessing how alert and energetic we feel during waking hours can provide insights into the restorative quality of our sleep.
Subjective Sleep Quality:
Self-reported assessments of sleep quality can offer valuable information. This includes rating sleep on a scale or describing our perceived sleep experiences.
Sleep Disorders:
The presence of sleep disorders, such as insomnia, sleep apnea, or restless legs syndrome, can significantly impact sleep quality and should be considered when evaluating overall sleep health.
Environmental Factors:
Consider the impact of the sleep environment, including noise, light, temperature, and comfort. An optimal sleep environment contributes to better sleep quality.
Sleep-Related Behaviours:
Factors like caffeine or alcohol consumption, screen time before bed, and irregular sleep schedules can influence sleep quality.
Emotional Well-being:
Emotional factors, such as stress, anxiety, or depression, can affect sleep quality. Addressing underlying emotional issues may contribute to improvements in sleep.
By considering these subdivisions, we (and healthcare professionals) can gain a more nuanced understanding of sleep quality and identify areas for improvement. It's essential to approach sleep quality assessment from a holistic perspective, considering both objective measurements and subjective experiences.
So now that we know what to look at when considering sleep quality - what would be a good checklist to determine whether our sleep is adequate? Don’t worry, we’ve got you sorted:
☐ We’re good at intuitively knowing if we’re sleeping well. Do you feel well rested?
☐ Do you wake up feeling refreshed?
☐ Do you have good cognitive function and mental clarity through the day?
☐ Are you feeling sleepy at roughly the same time each evening?
☐ Are you falling asleep within 30 minutes or less from when you get into bed to sleep?
☐ Are you waking up in the night and staying up for less than 30 minutes each night?
☐ Would you or are you waking up roughly the same time each day without an alarm?
☐ Are you getting anywhere between 7-9 hours sleep each night on average?
ACROSS A DAY WHAT CAN I DO TO SET MYSELF UP FOR GOOD SLEEP?
patterns of exposure to daylight
The first thing we’d look at are your patterns of exposure to daylight - this is because of your body's internal clock - it shapes the time of your biology e.g. when you feel sleepy, when you feel most alert, when you feel strongest in the gym, when your immune system is most powerful against pathogens e.g. the common cold. The timing of this clock is effectively set by light exposure - this isn't just the sun, this is also relatively intense light with short wavelengths, but if we’re comparing it to something, its like midday sun outside on a relatively bright day. Using this knowledge, if you expose yourself to this kind of light between 2 hours before you’d normally be waking up and 2 hours after you’d naturally wake up - you can shift your natural waking time to be slightly earlier. And conversely if you expose yourself to that kind of light later in the day e.g. 3-4 hours before you’d usually go to sleep and 2 hours after you’d fall asleep - that will tend to shift your body’s clock later. The relevance of this is that if you’re someone who stays up late, you may benefit from exposing yourself to this kind of light earlier in the day to effectively anchor your body clock to an earlier point and allow you to fall asleep earlier - potentially prolonging your sleep opportunity in the evening and in turn getting more total sleep and experiencing the benefits of that sleep! It’s also worth noting that spending time outdoors each day has a positive effect on regulating our body clocks - the timing isn’t a huge issue, but most of us don’t spend any significant amount of time outdoors - a good place to start would be to aim for 60 minutes of outdoor time each day. If you’re stuck indoors due to your work - know that sitting by a window is a good alternative option.
EXERCISE TIMING
Another aspect to look at is exercise - one relevant factor here to look at is the timing of your training - did you know that a key determinant of how strong you are across a 24hr period is actually your core body temperature? Your core body temperature tends to reach its peak in the late (biological clock) afternoon - which for a lot of people is close to 5pm. If we compare the amount of force that someone can produce when they are at their higher body temp readings e.g. 5pm compared to their lowest point e.g. 5am - on average we’re looking at an 8% difference in how much force someone can produce. We still need to be mindful of training very late though, especially if we’re expecting to sleep soon after. A recent meta analysis suggested that training within 4 hrs of bed didn’t have any meaningful impact on sleep - however, the types of training performed in the studies looked at didn’t reflect a similar style to strength athletes or bodybuilders. When we train as strength athletes, it’s not only the acute stimulus from lifting weights which is going to increase sympathetic nervous system hormones and adrenaline, noradrenaline etc., it’ll raise core body temp and increase cortisol production- all of which may contribute towards you being awake further into the night. But when you train you’re also exposing yourself to bright lights in the gym, loud music etc - all of which can negatively affect your sleep - in an ideal world we’d look to not perform any training any later than 3-4 hours before needing to go to sleep.
Training no closer than ¾ hours before bed isn’t a luxury that everybody has - so what can we do to speed up the rate at which we calm down after training? Using strategies like this may help us fall asleep faster and in turn have more opportunity for better, more productive sleep.
mENTAL STRESS
Another variable to consider is mental stress - a lot of the time we aren’t entirely in control of the events in our lives that cause us stress, however, we can definitely take measures to limit our exposure or mitigate damage here. E.g. If you find current news events distressing, you are in control of when you check the news. Another example is if you know you need to perhaps have a difficult conversation with someone, consider having that conversation in the middle or earlier on in your waking day rather than close to when you’re going to bed. Pre bed worry or rumination is a main contributor to a lot of peoples struggle to get to sleep.
CAFFEINE INTAKE
Your nutrition is also a variable to consider when looking to optimise your sleep - first focus here: caffeine. The way that caffeine affects our sleep is twofold: one mechanism is that if you’re consuming caffeine very late in the day, there’s a little bit of evidence to show that you can in fact shift your bodys internal clock a little later. The second mechanism is the fact that caffeine is an adenosine receptor antagonist. Adenosine is a neurotransmitter that promotes sleep and relaxation. Throughout the day, adenosine levels gradually increase in our brains, leading to a sense of drowsiness and the drive to sleep. This build-up of adenosine is part of the body's natural sleep-wake regulation. When you consume caffeine, it competes with adenosine to bind to its receptors. By doing so, caffeine effectively inhibits the sleep-promoting effects of adenosine. With adenosine receptors blocked, the usual signals of fatigue and drowsiness are blunted. This results in increased alertness, improved mood, and a sense of wakefulness, making it a popular choice to combat sleepiness and enhance focus. WHilst these effects are fantastic during the day and during training - they are not conducive to quality sleep. In order to avoid these impacts on sleep, we’d look at setting a ‘caffeine curfew’ of 8 hours before sleep - yes, if you’re going to bed at 10pm that means no more caffeine after 2pm! So what about dose? How much caffeine should we be looking at taking? There is a dose response relationship between caffeine intake and strength and power performance, so if we’re purely focused on the acute performance benefits we’d get from taking in caffeine - it would make sense to err on the higher end of caffeine intake - somewhere between 3-6 mg caffeine per kg of bodyweight - for an 80 kg athlete that's anywhere between 240 mg to 480mg. However, on a regular day to day basis we’d look to keep that number closer to the 3 mg/kg body weight figure and ideally not consumed within 8 hours of sleep!
eATING BEFORE BED
The other aspect of nutrition is what we eat and drink during the day - as well as our macronutrient layout. Ultimately the goal is to go to bed neither hungry nor full. Eating causes our core body temperature to rise and become higher than it otherwise would be. This is important to note because a drop in our core and brain temperature helps you fall asleep - eating too much too close to sleep can negatively affect our ability to sleep well at night. The inverse - going to bed hungry - isn’t great either. Hunger promotes food seeking behaviour and does lead to some hormonal changes that contribute to the nighttime wakefulness that athletes in later ends of deficit phases can experience. Finishing your final meal of the day no later than 2 hours before bed is a good place to start. Some of you may be thinking: but wait! I have 5 meals to get in during the day! I have a protein serving strategically before bed!
If your sole goal is recovery and maximising muscle accrual - then yes, this meal before bed may indeed have its place, but we’d recommend keeping it to just protein and not much else.
SETTING UP YOUR SLEEP SPACE FOR SLEEP QUALITY
Limiting blue light exposure
Same bed time each day
Set your bedroom up to be cool, dark, and comfortable
Look to control noise - e.g. use earplugs to block noise out or a fan to drown out distracting noise.
Keep your bedroom dark - opt for a blackout blind or an eye mask if your area suffers from light pollution and keep devices that emit light covered or turned off.
Invest in a quality mattress - generally speaking, heavier individuals will need firmer mattresses with greater levels of support. If you struggle with getting too hot in the night, know that spring mattresses are more effective at wicking away heat than foam mattresses.
You need to give yourself time to wind down at the end of the day. We’re talking 1-2 hours to wind down - in this time aim to:
Start to reduce the light you’re exposed to - e.g. dimming the lights, especially overhead lights.
Step away from stress
Having a hot shower or bath 1-2 hours before bed - this works to raise the temp of your skin by a few degrees which in turn triggers cooling of your body and dropping of your core temperature quicker than it would otherwise before bed - leading to you falling asleep slightly faster.
Listen to relaxing music, or read a book.
If you watch TV, watch something familiar and entertaining but not stressful, and be mindful of time passing - only one episode!
Put your phone into sleep or do not disturb mode. And stay off it!
In the realm of strength sports, optimising sleep is pivotal for peak performance and overall health. Understanding the specific impact on strength sports, injury prevention, immune function, and body composition underscores its significance. We can assess sleep quality through various dimensions to target improvements effectively - a practical checklist is a good place to start. Implementing daily habits, such as managing light exposure, optimising training timing, and addressing mental stress, all contribute toward fostering improved sleep. Recognizing the symbiotic relationship between sleep and sport specific success positions sleep optimization as an indispensable component of any plan. Embracing evidence-based strategies and cultivating a sleep-conscious lifestyle empowers us to enhance both performance and our health!