Drink water before, during and after exercise helps improve physical performance. One of the most important functions of water is to reduce the excess heat produced when muscles work or exercise.
The water in the blood and extracellular spaces (outside the cell) is transported to the epidermis (surface layer of the skin) and evaporated by heat (sweating), decreasing and regulate body temperature.
If your water levels drop your performance also decrease..
A loss of just 2% of body weight can reduce muscle strength and aerobic capacity by at least 10%. The problem is that if you feel thirsty while you exercise, it means you’ve lost that 2% of liquids, thus, must constantly hydrate before you feel the sensation of thirst.
If you lose 2% was bad, if you lose 4% of water due to dehydration, your performance will be decreased by 30%, and can begin to experience headaches, cramps, loss of concentration, fatigue and dizziness.
The danger is when you suffer one severe dehydration, typical example in high-performance sports and prolonged duration. It occurs when lose between 8 and 10% water. This can result from heat stroke in the best case, to cardiac arrest and subsequent death.
How much water should I drink?
Suitably 500ml drink before exercise. Then it is advisable to go drinking between 125 and 250ml every 10-20 minutes of training. If it is warmer than usual lose more fluids, so you will need to drink more water than usual.
Upon completion of the training, as you did before, you should drink another 500ml. I know it sounds a lot, but I assure you that at a meeting of spinning 45 minutes you can lose up to 1.5 liters of water through sweating.
Is it better to drink water or sports drinks?
If you train less than 1 hour, water is the best drink when it comes to replenish lost body fluids.
The isotonic drinks or sports (containing carbohydrates and minerals) are more beneficial for athletes who perform high-intensity exercise and for more than one hour, as they help fight fatigue and maintain levels of blood glucose when levels of muscle glycogen (energy reserve) down.