We all know the importance of hydration during exercise, but do we really know how to measure it? As most people know, sweating leads to fluid and electrolyte loss. If we don’t replace the lost fluids or electrolytes we become dehydrated, leading to muscle fatigue, confusion, lack of coordination, inability to regulate heat and heat exhaustion.
It is important to know how to measure your water loss as it varies person to person, you can do this by weighing yourself before and after exercise and checking the colour of your urine. and ensure you are hydrated prior to exercise. The darker the colour the more dehydrated you are. The ACSM guidelines for dehydration and weight loss are as follows:
Well hydrated: -1 to +1% (body weight (bw) change), Minimal dehydration: -1 to -3% (bw change), Significantly dehydrated: -3 to -5% (bw change), Severely dehydrated: -5% (bw change)
As stated above, prior to exercise you should check the colour of your urine and weigh yourself. If your urine is dark to very dark, be sure to hydrate as follows at least four hours prior to exercise: 16-20 fluid oz (450 - 570 ml) water or carbohydrate (5-8%) sports drink. Then 10-15 minutes prior to exercise take on 8-12 fluid oz (230-340 ml) of water.
During exercise for under 60 minutes you should take 3-8 fluid oz (85-230 ml) water. For over 60 minutes exercise you should ingest a carbohydrate/electrolyte sports drink 3-8 fluid oz (85-230 ml) every 15-20 minutes. DO NOT CONSUME more than 1 lt per hour of fluids!
When you have completed your exercise, be sure to weigh yourself to determine how much fluids you should ingest within 2 hours. ACSM guidelines suggest 20- 24 fluid oz (570-680ml) for every pound lost.
Be careful not to overhydrate as this can lead to a potentially lethal condition so do not ingest more than 1 litre per hour of fluids. If you suspect you have over-hydrated contact your GP to begin tests.
I hope this helps to keep you hydrated this spring and summer.
If you have any questions about sports injuries and rehabilitation, please contact me at sara@prestigesportinjury.co.uk
