During sleep, hormones are released that support different bodily functions, including our growth, strength, and other aspects of our physical development.
The body uses this time to repair tissue and restores energy levels – improving coordination, boosting reaction times, increasing mental and physical stamina, and even making us faster.
The NHS says good sleep also helps to recover faster from injury, boost our immune system and maintain weight.
Sleep also improves memory and learning, with a lack of sleep making it harder to concentrate and retain information.
“If you want to push the mind, you need to detoxify your mind. How do you detoxify? You can only detoxify with a good sleep,” said Menon.
“Sleep makes all the difference. When they get onto the pitch or the training, we can see the decision-making scale, clarity, and even the way they breathe – everything changes.
“The timing, the sense, the teamwork – everything comes with this deep state of clarity. That is the mental detoxification. The proper brain detoxification only can come through sleep.”
Sleep specialists, like Menon, say they can identify players who have not slept well or not recovered properly simply by their appearance.
At an elite level where marginal gains can make the difference between winning and losing, wellness coaches are being brought in to educate players and find an edge.
The NHS says adults require between seven and nine hours of sleep per night, but Menon and other coaches say duration alone is not the most important part of sleep hygiene.
“Sleep, it’s not about the time, [it is about] the quality. The day you are not sleeping well, your creativity is missing,” Menon says.
“Football is all about creativity and [the] uncertainty is so high because the lifespan of the footballer is very short. Even the manager. Because if [the manager] is not performing, he is out. If the team is not performing, [the manager] is out.
“If one player is getting injured, all the stress is coming to the medical team and the manager is also getting the stress because my specific player is not available.”
Azpilicueta knows all too well about the importance of sleep, saying: “It’s a big part in performance and now you try to get every detail and the competitive advantage on the highest level. The margins are very thin and it’s very tight, so every club wants to make the most of it.”
It is common for footballers to play late at night and also travel back home after away matches. Azpilicueta cites one game in particular as an example, when he thought he’d scored the winner in a 4-4 draw against Ajax in 2019.
“Really bad,” Azpilicueta said of his sleep that night. “Because it was my first time I scored two goals in a Champions League game.
“The comeback, after all the emotions and the red cards and more than the goal, you have the emotion and that emotion doesn’t go away from you.
“And then just being disallowed by VAR, that gives you a bit of the momentum. But [after] that, it’s harder to sleep at night.”