Elite footballers face increasing physical demands, with matches often extending beyond 90 minutes. To combat fatigue, athletes are turning to liquid carbohydrate supplements to replenish glycogen, the primary energy reserve for muscles. A study found that players consuming liquid carbohydrate between games improved performance, covering more ground and maintaining higher heart rates with less muscle soreness. Although not all players benefit equally, those who do have significant advantages, underscoring the importance of tailored nutrition and recovery plans.
Elite football is more intense than ever before – practice schedules are more punishing, competition is fiercer and in international tournaments such as Euro2024, games increasingly go into extra time, extending play from 90 minutes to 120 minutes.
“The demands of this sport are very high,” says Georgios Ermidis, a sports scientist at the University of Southern Denmark who has studied the physiology behind football for more than a decade. And while “there is more of a breakdown in the body after a football game compared with other sports like basketball,” Ermidis says that there are surprisingly few data on how back-to-back 120-minute games affect a footballer’s recovery.
So what can players do to stay on top of their game through an extra 30 minutes on the pitch? For years, elite footballers have been guzzling liquid carbohydrate. Pasta and rice come to mind when most of us think of carbohydrate, but athletes rely on “very sweet” drinks or gels full of simple carbohydrates that can be absorbed quickly to replenish glycogen, the muscles’ in-house energy storage system, Ermidis explains.
Although the benefits of carbohydrate drinks during a 90-minute game are well documented, Ermidis says that no one had ever quantified what kind of boost carbohydrate beverages can give players facing back-to-back 120-minute games. Ermidis and colleagues set out to determine whether they could find a difference between players who sipped carbohydrate and those who did not – both in their performance on the field and in their cells.
Like drinking 14 servings of spaghetti
As part of a broader study on extended football game play funded by UEFA, researchers recruited 20 male footballers in Greece to play two 120-minute games with a three-day break in between – about the time allowed for recovery during tournament play.
To determine how carbohydrate drinks affect in-game performance and recovery, all 20 players were asked to drink chocolaty beverages between their first and second games. Some were zero-calorie placebos, and some contained 48.3 grams of carbohydrate (for reference, a serving of spaghetti has about 31 grams). The players downed one drink right after the first match and eight more with meals over the next several days until the second match. For the players who received the active drinks, this is the carbohydrate equivalent of 14 servings of spaghetti in four days.
Ermidis and his colleagues gathered extensive data on the footballers’ performance during both games. GPS tracked the speed and duration of their movements on the pitch, while tests on the sidelines including sprints and jumps assessed the players’ abilities before the game, after 90 minutes and at the 120-minute mark to determine their rate of fatigue. The players were even weighed throughout the game to track their sweat loss.
The researchers also collected biological samples to see how the players fared at the cellular level. At the same time points, the scientists collected blood samples and small biopsies of a muscle in players’ dominant legs. “It was maybe the most demanding study I have ever done,” Ermidis says, referring to the time pressure to collect all the data and samples from 20 players simultaneously without interrupting the flow of the game. “We needed a lot of manpower.”
Carbohydrate drinks are worth it – especially for super responders
Analysing this wealth of data revealed that the extra carbohydrate helped players to recover for the second 120-minute game, Ermidis says.
Footballers who had not received the carbohydrate supplements fared worse in the second game than the first – they covered less ground and had fewer accelerations and decelerations, and their heart rate was lower. The players who drank the carbohydrate supplements suffered none of these penalties, Ermidis says. In contrast, carbohydrate supplementation did not seem to affect high-intensity running distance, sprinting distance or sweat loss.
Perhaps most importantly, Ermidis says, the carbohydrate supplements helped players to rebuild their stores of muscle glycogen, “the main fuel we lose after prolonged exercise.” The researchers inspected individual muscle fibres for glycogen under a microscope and found that 64% were partly or completely full by the time of the second game among players who drank the carbohydrate supplement versus 58% in the placebo group.
Analysis of the blood samples found more chemical signals of inflammation and decreased immune system activity among players who did not receive the carbohydrate supplements – a phenomenon documented in other sports but now observed for the first time in football, Ermidis says. And from the players’ perspective, footballers who drank the extra carbohydrate were less likely to report getting sore after the game.
Although the average effects were modest, Ermidis says that pulling apart the data further suggests that some players may benefit more than others from extra carbohydrate. This was especially evident based on the muscle biopsies, he adds. “For some reason, some people’s bodies seem to react better,” Ermidis says.
Although it was not the focus of their study, Ermidis says that the results underscore how much recovery differs for different players. The sideline tests and biological samples showed that some players were “ready to go for another 120 minutes” after the 72 hours of recovery, whereas others clearly needed longer for their bodies to catch up. “Individuality is important,” he says.
In the future, tests like these could help coaches to decide which players to start and which to hold back for the next game, Ermidis adds.
Even if not everyone is a super-responder, Ermidis says that elite athletes should all be drinking carbohydrate. “I had in the past one or two players who thought that carbohydrate drinks were a bad idea – they thought they would gain weight and it would not help them in the game,” he explains. But with proper education – and the help of these new data – he hopes to dispel those doubts.
“If there is a player at the moment who does not take carbohydrate in-game, I think it will be clear in his performance. It will be a problem for him,” Ermidis says.
