Article on Hydration by Ian Fergus

It has always seemed strange that in football nutrition has generally been low on the priority list, if it has featured at all. Every club expects the players to train, but it hardly seems worthwhile insisting on this if the opportunities offered by good nutrition are neglected.

One of the key areas where nutrition can have a direct impact on performance is in the area of hydration. There is good evidence that players who become dehydrated are more susceptible to the negative effects of fatigue, including loss of performance and increased risk of injury. There is also growing evidence that excessive sweat losses, especially high salt losses, can be a factor in some of the muscle cramps that affect players in training and competition.

Recently, however, a number of clubs have recognised that hydration is important and that no single strategy suits all players in all environments. This has led to an assessment of individual needs so that a personal drinking strategy can be put in place. This practice appears to have gained ground overseas, where pre-season training typically takes place in extreme heat and involves two sessions per day. In recent years, several of the top football clubs now have monitoring strategies in place.

Zero-cost analysis

At its simplest level, weighing of players before and after training gives an indication of their level of dehydration and risk of heat illness. This takes account of both the amount of sweat lost and the amount of fluid drunk and gives the net balance. There will be a small amount of weight loss due to the fuels used to produce energy (mostly carbohydrate, with a bit of fat), but this amount is relatively small. There will also be water loss from the lungs and loss through the skin. Broadly speaking, a weight loss of 1kg represents a net loss of 1L of body fluid. Also 1% dehydration is believed to affect 10% of your concentration levels.

A slightly better measure is obtained if the player is weighed before and after training or competition and his (or her) drinks bottle is also weighed before and after, assuming that all players drink from their own bottles and that anything that is taken from the bottle is swallowed and not spilled/poured over the head/spat out. If the decrease in weight of the drinks bottle is added to the decrease in weight of the player, we get the actual sweat loss. We also get a measure of the player’s drinking behaviour.

All of this is easy to do, and all it requires is a set of kitchen scales to weigh the drinks bottles, a reliable set of scales to weigh the players, and a bit of organisation. The cost is effectively nil – just a bit of time and effort on the part of one of the backroom staff. I hope this is beneficial to you.

IAN FERGUS,    YOUTH FOOTBALL COACH