Buzz
"Get plenty of rest" is timeless advice for anyone preparing for a big race or event. But what happens if you stayed up late choosing the perfect shoelaces, only to wake up early to make it to the start line on time? Could this hurt your chances of performing well?
The Impact of Sleep Deprivation on Exercise Performance
You’re probably aware of the mental side effects of sleep deprivation: irritability, poor decision-making, and the overwhelming urge to crawl back into bed. But these parts of your brain aren't necessarily needed for running or exercising. What's more, exercise itself can help shake off some of these effects—making the relationship between sleep deprivation and exercise performance more complex.
Lack of sleep might slow you down. A study published in the European Journal of Applied Physiology found that men who stayed up all night covered slightly less distance in a 30-minute treadmill test compared to when they were well-rested. The difference was small: 3.86 miles versus 3.75 miles, on average. In contrast, a similar study with male cyclists published in Aviation, Space, and Environmental Medicine found no difference in the distance covered, though sleep-deprived cyclists felt their performance had suffered.
When it comes to aerobic activities like running or cycling, the difference in performance due to lack of sleep is typically minor or negligible. The same holds true for partial nights of sleep, not just full all-nighters. A review published in Physiology and Behavior concluded the following about partial sleep deprivation:
Aerobic sports (such as distance running) and anaerobic sports (like sprinting): the difference in performance after poor sleep is usually 'marginal,' and you may not even notice it.
Repeated anaerobic activities, such as weightlifting: Increased fatigue.
Sports requiring concentration and strategy: Decision-making ability is impaired.
Precision sports, including those involving aiming at a target: You’ll likely make more mistakes.
This aligns with the classic runner's rule: Don't stress about your sleep the night before a race, as long as you're well-rested beforehand.
Another factor influencing performance is the time of day. Athletes tend to perform better in the afternoon or evening than in the morning. Sleep deprivation can diminish this afternoon performance boost. A martial arts study published in the Journal of Strength and Conditioning Research showed that athletes performed better in strength and muscle power during judo competitions in the afternoon when well-rested, but their performance in both morning and afternoon events was the same when sleep was cut short. While many runners race in the morning, other sports are scheduled later in the day, and long endurance events like triathlons may have multiple start waves. If you can choose your start time, it’s better to opt for the afternoon—if you’ve had a good night’s sleep beforehand.
What to do if you find yourself having to skip sleep before an important event
There are times when you just know you’ll miss sleep, particularly when your race begins early. Think about whether you can realistically get to bed on time or if you'll likely be occupied with traveling, prepping, or just too excited to rest early.
If you're aware you'll miss sleep the night before your event, try to catch up earlier in the week. For a major event like a marathon, you'll likely already be reducing your exercise, staying hydrated, and perhaps loading up on carbohydrates. Make sleep a priority during this period. With some extra hours of sleep banked, that one bad night won't make much difference.
Adjust your bedtime earlier by thinking about a study involving basketball players published in the journal Sleep. These athletes didn’t feel sleep-deprived initially, but when they stayed in bed for at least 10 hours each night, their sprint times improved, their shooting accuracy increased, and they experienced better physical and mental well-being.
If you're faced with choosing between missing sleep early or late, the judo study offers insight: waking up early caused more significant declines in afternoon strength than staying up late. So, if you have to travel, for example, it might be more beneficial to arrive at your destination during the night and get a few hours of sleep, rather than waking up early and spending your morning traveling.
When you finally wake up, the same tips that get you through your workday will still apply. Avoid hitting the snooze button (those extra ten minutes won’t really help) and instead, get some sunlight right away and enjoy a healthy breakfast that’s tried and true.
Your breakfast should likely include coffee, and here’s why: First, caffeine helps you wake up—plain and simple. Second, caffeine boosts performance in endurance events and sports. You should never try anything new on race day, but if pre-run caffeine worked for you during training, use it on race day as well. Stick to a similar amount you’re accustomed to (keep in mind some energy gels and drinks already contain caffeine), and don’t forget: coffee will make you poop, so time it wisely.
Finally, caffeine can also help combat some mental effects of sleep deprivation. It might help you make better decisions (which is crucial if your event involves strategy). As for its impact on accuracy in sports, the results are mixed: caffeine helped rugby players, but didn’t show the same effect for tennis players.
When to skip a workout
Planning for a race is one thing, but what do you do when you’re just too worn out for your regular workout?
If you wake up feeling exhausted on a day with an important workout, such as a long run leading to a marathon, think of it as a race. Even if the workout feels difficult, remember that you can still gain benefits from it. You can take it easy if needed, just focus on completing the workout.
On those groggy days, you're often at your peak in the morning, but by evening, you tend to fade both mentally and physically. This may mean it’s best to work out in the morning rather than later. But if you have the chance to work out in the morning, you could also opt for a longer sleep or perhaps take a rejuvenating nap later on.
In most situations, your first step should be to ask yourself why you're feeling so tired. If you're tired occasionally, skipping a workout won't make much of a difference. However, if skipping workouts becomes a regular habit, it may be time to rethink your schedule. You might have a major workout planned for a day with other pressing deadlines, and in that case, either move the workout or, ideally, manage your time better to avoid frequent all-nighters.
Illustration by Tara Jacoby.
