Proper hydration sustains the body’s physiological responses in all activities, but the physical and mental stresses of athletic training and competition magnify the importance of hydration. Numerous studies conducted on athletes since the 1940s have demonstrated that even mild dehydration impairs performance.
Athletes should avoid losing even 2% of the total body weight in water.
- Studies performed since the 1940s have shown that a loss of water equal to 2% of the body weight impairs performance.
- Recent studies have shown performance loss at dehydration levels less than 2% of body weight.
- Dehydration causes reduced aerobic endurance and increased body temperature, heart rate, and reliance on carbohydrate as a fuel source.
Prehydration: drinking water before exercise
- The goal of prehydration is to start an exercise activity in an euhydrated state.
- Euhydration means the body is hydrated and plasma electrolyte levels are at a normal level.
- Prehydration should be performed several hours before exercise to enable fluid absorption and allow urine output to return to normal levels.
Hydration: drinking water during exercise
- The goal of hydration is to prevent excessive water loss through perspiration.
- Individual perspiration rates can be estimated by weighing yourself before and after exercise.
- Each pound of body weight equals one pint (8 ounces) of water lost.
- The goal is to prevent water loss in excess of 2% of the total body weight or one becomes dehydrated.
The ideal composition of drinking water for sports.
- Experts long thought salt (sodium) needed to be added to the water to replace salt lost through perspiration.
- Current thought is that athletes consuming a traditional Western diet have consumed an abundance of salt, so there is no need to replace salt when exercise last less than two hours.
- Water that has been alkalinized may help neutralize the exercise induced acidosis (lactic acid build up), since the pH of alkaline water is high.
- Ionized water may help act as a free-radical scavenger to address the issue of accelerated oxygen consumption.
- Ionized water is micro-clustered, so it may be absorbed at a faster rate, helping with rehydration.
Dr. Peter L. Kopko, D.C., recommends drinking 13 to 20 ounces (2-3 cups) of water 2 hours before exercise and 5 to 10 ounces (about 1-2 cups) every 15 to 20 minutes of exercise, depending on your total body weight.