Hydration is critical for maintaining endurance performance. Working muscles generate enormous amounts of heat. Without adequate cooling, in a little over five minutes of intense muscle activity, your body temperature could rise to life threatening levels. This rapid rise in temperature is prevented by our sweat mechanism. However body cooling has other repercussions, primarily loss of plasma volume. As little as a two percent loss in blood volume significantly decreases endurance performance, increases heart rate and increases fatigue. Two per cent isn’t much. Just three lbs. for a 150 lb. person. This is not an uncommon loss, especially when exercising in hot weather. Here are four simple hydration tips to help you maintain peak performance.
- You can’t totally replace the fluid you lose via sweating. It is not unusual to lose 32 oz. or more fluid per hour, especially in warm weather, your GI tract can only absorb 25 oz. per hour. If you try to match consumption with sweat loss you will get sick. During exercise your body can function well with a slight fluid deficit.
- It’s not about how much you drink but how much your body absorbs. For more efficient absorption consume smaller amounts of fluid more frequently and start your consumption a few minutes into your workout. With this regimen you will absorb more fluid.
- Water is not the best fluid for rehydration. Addition of salt improves the absorption of water significantly. Water follows the movement of sodium and other transporters such as simple sugars, protein, zinc and the amino acid, alanine. Studies have shown that the most effective sports drinks are those which contain multiple sodium transporters. For example Accelerade, which contains electrolytes, simple sugars and protein. Accelerade re-hydrates 15% more than a conventional sports drink and 40% better than water.
- Dehydration is cumulative. After a hard workout it’s essential that you fully rehydrate before your next workout. A small fluid deficit in your blood volume of 4-5 ounces can significantly reduce performance in a subsequent workout. The simplest way to measure your hydration state is to look at the color of your urine. It should be the color of pale lemonade.