Is sleep the best supplement for athletes?

Now you might be wondering: what on earth does sleep have to do with sports nutrition? Well, more than you think! Because while you invest in nutrition, training plans, and supplements, one of the most powerful recovery and performance factors is free and available every night. Yet, sleep is systematically underestimated by most athletes. In this article, I'll explain why sleep and sports nutrition are inextricably linked, and what you can concretely do about it.

What actually happens while you're sleeping?

Sleep feels passive, but your body is hard at work at night. Your muscles repair, your hormone balance is readjusted, and your energy reserves are replenished. These are precisely the things you as an athlete want to optimise, and they largely happen while your eyes are closed.

Your body produces the most growth hormone during the first few hours of sleep. This hormone plays an important role in muscle recovery and fat burning. Your reaction speed and coordination, things you really need during sport, are also adjusted at night. In short: sleep isn't a pause between two training sessions. It *is* part of your training.

Researchers studying sleep and sport are increasingly describing sleep as the most important recovery factor that exists. More important than nutrition, supplements, or active recovery. That is a strong statement, but the logic behind it is simple: all other recovery strategies only work optimally when sleep is in order. You can eat as well as possible, but if your body doesn't get the rest it needs at night, a large part of that work will not be utilised.

What does sleep deprivation do to your body?

You know what a bad night's sleep is like: you feel sluggish, have more cravings, and perform less well. But if that becomes a structural problem, the consequences are greater than most athletes realise.

When you don't get enough sleep, your stress hormone levels rise, making it harder for your body to recover from exertion and easier to store fat. At the same time, the hormones crucial for strength development and recovery decrease. No supplement can compensate for this.

Your appetite also gets out of sorts. You feel hungrier, specifically for quick carbohydrates and fatty foods, while your body doesn't need those extra calories at all. No matter how conscious you are of your diet, with chronic sleep deprivation, you're working against yourself.

And then there's the way your body handles carbohydrates. With a lack of sleep, this process is less efficient, meaning your energy levels throughout the day are more erratic and your recovery after a workout is slower. In short: sleep deprivation sabotages virtually everything you try to build with your diet and training.

In the short term, you notice this mainly in your performance: you're less sharp, make mistakes more quickly, and struggle to keep up. But research also shows what happens in the longer term when sleep deprivation becomes a habit. Athletes who structually sleep less than seven hours demonstrably build less muscle mass. Even if they eat enough protein and train regularly. The body simply needs sleep to process the training stimulus and translate it into adaptation. (Gorman et al., 2025 – https://pmc.ncbi.nlm.nih.gov/articles/PMC12263768/)

Furthermore, the risk of injury increases. This may sound surprising, but the link is clear: with a lack of sleep, your nervous system reacts more slowly, your coordination deteriorates and you are less able to move your body as you are accustomed to. Small inattentions that your rested self would never make, then suddenly become an ankle injury or a moment of strain. So sleep protects you not only from the inside, but also from the outside.

Finally, sleep plays a striking role in how you cope with exertion. Well-rested athletes perceive the same training as less strenuous than poorly rested athletes, while the objective load is exactly the same. (Frontiers in Physiology, 2025 – https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2025.1544286/fullIn other words: sleep literally makes training easier. Not by making you fitter, but because your body and mind are better able to cope with the load.

What has nutrition got to do with it?

This is where it gets interesting. Because while food cannot replace sleep, you can definitely influence it.

Protein for sleep. Muscles recover best at night when sufficient building blocks are available. Research by Maastricht sports nutritionist Luc van Loon shows that a protein-rich snack just before bed measurably increases muscle protein synthesis during the night. (Trommelen et al., 2023 – https://link.springer.com/article/10.1007/s40279-023-01822-3Think of quark, a glass of milk, or a plant-based alternative like soy drink. Not necessary every evening, but certainly worthwhile after a tough workout.

Magnesium. This mineral helps your muscles relax and plays a role in a good night's sleep. Athletes lose more magnesium through sweat than people who don't exercise, so the requirement is somewhat higher. You can find it in, among other things, nuts, seeds, legumes, and green vegetables. Nutritional research shows that a large part of the population already consistently gets too little magnesium. So, for athletes, it's extra worthwhile to be consciously aware of this.

Nutrition that supports your sleep rhythm. Your body naturally produces more melatonin in the evening: the hormone that signals it's time to sleep. Certain nutrients help with this. Bananas, oatmeal, nuts, and legumes contain substances your body uses for this purpose. Not a miracle cure, but a nice contribution. Interestingly, research also shows that cherry juice can slightly improve sleep quality in athletes, presumably due to the naturally occurring anti-inflammatory substances and melatonin precursors in sour cherries. (Vitale et al., 2021 – https://pmc.ncbi.nlm.nih.gov/articles/PMC8150598/Not something to rely on every night, but a nice example of how diet and sleep can intertwine.

Timing of your last meal. A heavy meal right before bed places a significant demand on your digestion, which can disrupt your sleep quality. At the same time, you don't want to short-change your body after an evening workout. A light, protein-rich snack about an hour before bedtime is a good compromise for most athletes.

Coffee and alcohol. Two things athletes often underestimate. Caffeine remains active in your body for a long time: a cup of coffee at three in the afternoon will still have an effect in the evening, even if you don't notice it yourself. And alcohol? It might help you fall asleep faster, but it significantly disrupts the quality of your sleep, meaning your recovery at night is much poorer than you might think.

Where do you start?

You don't need to change everything at once. Start with the basics: get enough sleep. For most adult athletes, that's seven to nine hours. And try to keep that consistent, even on weekends. Then, see if you can add something protein-rich before bed after a tough workout. And pay attention to when you have your last coffee.

Small adjustments, but they can make a noticeable difference in how you train, recover and feel.

Conclusion

The best investment you can make as an athlete costs no money and is available every night. Sleep is the foundation on which everything else rests: your nutrition, your training, your recovery. Look after it.

Would you like to know more about the basics of sports nutrition?

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