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Sleep plays a key role in people’s health in general and, besides, it is an essential biophysiological variable for athletes.
Football has evolved a lot in recent years, and the physical demands are increasingly higher. In addition to proper planning of training, nutrition plays a fundamental role in helping athletes to achieve the optimal sporting performance. Specifically, among many other variables, nutrition on the days around the match can condition performance both during and in subsequent workouts. However, there is still much controversy as to which nutritional strategies really are scientifically supported and which are not. Therefore, it could help to assess the opinions of experts in this field in order to present the most recommended nutritional strategies.
Within this context, the UEFA panel of experts – which includes FC Barcelona nutritionist Dr Antonia Lizarraga, as well as other coaches, scientists, doctors, nutritionists and, in general, professionals from the world of football – has drawn up a series of football-related nutritional recommendations, including for the moments before, during and after a match, which have been published in the prestigious British Journal of Sport Medicine.1
Given the importance of carbohydrates for performing actions at high intensity, before a game it is essential to try to “fill” the glycogen stores to the maximum. To do this, training the day before a match should normally be light, and players should try to ingest a high amount of carbohydrates (6-8 g/kg) to promote the replacement of muscle and liver glycogen. That amount of carbohydrates would be equivalent to 420-560 grams per day for an average 70 kg athlete, and could be achieved by increasing the intake of foods such as fruits, pasta, rice, potatoes and bread throughout the day (considering, for example, that a dish of boiled rice is equivalent to approximately 60 grams of carbohydrates, that a banana contains about 30 grams of carbohydrates, or that two slices of bread contain approximately 25 grams of carbohydrates), and can also be supplemented with sports supplements (bars, carbohydrate drinks, etc.). In addition, when several games are played in a short period of time (48-72 hours), this high carbohydrate intake should be maintained on the days in between.
On the other hand, hydration must also be controlled before matches by monitoring body weight, perception of thirst, colour of urine, osmolarity and specific gravity of urine, trying to get players as hydrated as possible ready for the start of the game. Solely basing intake of fluids on the perception of thirst may not be enough, so planning the intake individually (based, for example, on each player’s sweat rate) could be advisable to ensure optimal hydration.
In order to achieve the highest possible glycogen levels, on match day it is advisable to maintain that intake of 6-8 g/kg of carbohydrates, including a carbohydrate-rich meal 3-4 hours before kick-off (1-3 g/kg, equivalent to 70-210 grams of carbohydrates for an average 70 kg athlete, which can be achieved for example with a large dish of pasta or rice, a banana and one or two slices of bread). This is especially important to keep glycogen levels in the liver high, as they can drop overnight. This pre-game meal should include foods that are easily digestible to avoid gastrointestinal problems, but to a certain extent the players’ usual habits need to be respected so that they feel comfortable. Players also need to arrive for the game in a good state of hydration, ingesting 5-7 mL/kg of liquid in the 2-4 hours prior to kick-off (approximately half a litre of water for a 70 kg player).
Keeping carbohydrate intake high during games can help improve physical as well as technical and cognitive performance. For example, various studies have observed that an intake of 30-60 g/h during a match, or 60 g before each half, can be beneficial strategies (considering, for example, that a litre of isotonic drink contributes around 60 g of carbohydrates, or that a 60-gram bar can contain about 40 grams of carbohydrates).2 Therefore, experts recommend ingesting 30-60 grams before warming up and another 30-60 grams at half-time, with sports supplements (especially carbohydrate drinks) possibly being a good alternative to reduce gastrointestinal symptoms. In addition, merely gargling a carbohydrate drink (without actually swallowing it) could be beneficial for performance by stimulating receptors in the oral cavity and producing positive effects on the central nervous system,3 which could be a potentially beneficial alternative for players who suffer from gastrointestinal symptoms.
As for hydration, this varies between players as also does sweat rate, which varies on average between 0.5 and 2.5 L/h.4 Indeed, it has been suggested that players should avoid dehydration that involves a loss of more than 2-3% of body weight, and should also try to avoid over-hydration that leads to an increase in body weight. These strategies, both carbohydrate intake and hydration, should be practiced in training sessions and lower-priority games so that they can be perfected and individualised in as much detail as possible, thus getting athletes used to them.
Once the game is over, we must not forget the important role of nutrition for promoting recovery as quickly as possible. In order to replenish the glycogen stores, players should aim for an intake of 1 g/kg of carbohydrates per hour for 4 hours after the game (i.e. 70 grams for a 70 kg athlete), which is usually done by ingesting sports drinks and/or in the changing room followed by some food in the stadium, on the road, and at home. These intakes must also be accompanied by liquid to facilitate rehydration. It is important to note that sometimes, especially when games are played at night, it can be harder to get proper carbohydrate intake immediately after the match. In these cases, special attention must be given to the intake in the subsequent 24 hours, which should be 6-8 g/kg during the following day and which should be maintained for the following 48-72 hours in the event of there being several games in a row.
However, in addition to carbohydrates, it is important to control protein intake to promote post-exercise muscle recovery, ingestion of 20-25 grams of protein being recommended every 3-4 hours after exercise (which can be achieved, for example, with about 100 grams of chicken breast or just over half a litre of milk). Furthermore, although more studies are needed in this regard,5 growing evidence suggests that other interventions such as the intake of polyphenols from cherries could improve various recovery factors such as performance and even inflammatory markers, as confirmed by a recent meta-analysis.6 Finally, the intake of antioxidants like vitamin C or E could reduce oxidative stress and limit the body’s endogenous antioxidant response, which is necessary for muscle adaptations to occur with training.7 Therefore, the intake of antioxidants must be regulated according to individual objectives at each moment of the season, since in some cases it can limit adaptations to training but in situations where there are several matches in a row and where quick recovery is needed (and not muscular adaptations) it could be beneficial.
Player nutrition before, during and after games can have a major influence on in-game performance, as well as on subsequent workouts. Before and during the game, the main goal will be to maintain the proper state of hydration and to try to arrive for the game with the glycogen stores as full as possible, and also to supply carbohydrates during the game to avoid depletion. After the game, not only should players re-hydrate and recover glycogen levels as quickly as possible, but it is also advisable for them to ingest proteins to promote muscle recovery and thus performance in subsequent sessions.
Pedro L. Valenzuela