Q: Watching my grandchildren playing sport these days seems to involve very frequent drinks of water for all those taking part. This also happens at the gym I go to. Is it necessary? We never used to do this in the past.
A: This certainly seems to be the current habit, but it is probably no more than a habit as there is very little science to confirm that drinking during sport is necessary unless you are involved in endurance sport going on for many hours.
One of the key features of the amazing human body is its ability to adjust fluid content and body salt concentrations within tiny margins.
Related: How much water do we really need to drink?
If you are doing sport and sweating heavily the body makes adjustments to loss of fluid elsewhere.
If you drink a litre or two of water then again adjustments are made and any excess of fluid is automatically lost through sweating, urine and other methods.
Faced with this marvellous machinery it is hard to know why it has become fashionable to drink during sport.
It is undoubtedly driven on by elite athletes, footballers and rugby players all seen taking drinks on our televisions.
Part of this is a misunderstanding of biology and in part due to pressures from the drinks industry and the associated advertising.
The drinks industry tends to market sugary drinks for sport, again there is no evidence that either the sugar or the fluid are necessary for a normal length football match, a gym session or similar.
If you are a marathon runner or an endurance athlete then the situation is different, the rest of us can rely on our bodies to make the necessary adjustments and to take fluids as and when our bodies say.
A case of listening to our bodies rather than to the advertisers or habits of others.
Related: Stay hydrated with our tips