By experimenting athletes can determine how much fluid they require to maintain weight and how much fluid intake they can tolerate without experiencing stomach cramps. The determination will be most accurate if the athlete is weighed before and after a typical workout. For every half kg lost , half liter of water should be consumed during exercise, which appears to be 800ml/hour. Therefore balance should be struck between fluid loss and fluid intake. Research has shown that relatively small volume at regular intervals can help prevent severe dehydration and bloating.
Although a large volume of ingested fluid (upto 600ml) increases emptying rate, gastric discomfort may result. Drinking 100-200 ml/10-15 minutes seems appropriate.
Drinking schedules should go as;
Two hours before exercise: 500-750ml
20 minutes before exercise: 250-500ml
During training; 150-250ml every 10-15min.
After training: replace water as 1.25 to 1.5 liters per 1kg of body weight lost
Drinks should be cool (5-10°C) to help promote rapid gastric emptying. Chilled fluids (6-12°C) empty from the stomach more quickly than 35°C, wrm ones and decrease body temperature .
The question is to drink water or some type of carbohydrate- electrolyte drink- body fuel, excess, and gatorade. For sports requiring less than 30 minutes of exertion, replacing the water lost in sweat is the primary concern because losses of body carbohydrate stores and electrolytes- sodium, potassium, chlorine and other minerals are not too great in such activities. Electrolytes are lost in sweat, but quantities lost in exercise of brief to moderate duration can be replaced later by consuming normal foods, like orange juice, potatoes and tomato juice.
For activities lasting more than 60-90 minutes of exercise, electrolyte replacement becomes increasingly important. Prolonged exercise results in large sweat losses and some fluid for sweating comes from the bloodstream. If plain water is used to replace fluid losses in the blood, the concentration of the essential electrolytes in the bloodstream may become too diluted. Therefore it is important to include small amounts of sodium and potassium in sports drinks to maintain blood volume.
Beverages containing various mixtures of nutrients such as carbohydrates and electrolytes are called nutrient beverages. The ideal athletic drink also should supply water to compensate for sweat losses during exercise. Dehydration due to excessive sweating causes gradual reduction in performance during exercise in the heat.
Large volumes of a low carbohydrate drink should be ingested in the heat, whereas smaller volumes be ingested with high carbohydrate content are advantages in cold weather. Including carbohydrates in sports drinks has been found to delay. Fatigue in endurance exercise. Three hour marathon space including carbohydrate improves endurance either by preventing great drops in glucose or provides an outside source of glucose for muscle use. Carbohydrate in the drink replaces carbohydrate used up during exercise/ practice/ competition. Sodium present also aids in glucose absorption.
The ideal sports drink to be used during exercise has a carbohydrate content of between 40-80g/L, and has NaCl content (400-120 mg/L). To fill the stomach, 6-8 mL/kg body weight each 15-20 min during exercise.Water is cheaper than sports drinks. They taste better than water. Therefore athletes may drink more than often.
Poor beverage choices include Caffeine and ALcohol
As caffeine is present in tea Caffeine is present in tea coffee and soft drinks it is a stimulant and diuretic so in hot environments it increases the risk of dehydration it serves as a CNS stimulant, reduces fatigue, increases alertness and boosts muscle capacity. The diuretic effect of caffeine was recently demonstrated in a study of 12 healthy German men and women who were usual coffee drinkers but abstained from drinking or eating anything containing caffeine for 5 days before the study. 6 cups of coffee led to training increase in 24 hour in urine excretion of 753 ml and negative fluid balance and decrease in body weight of 0.77 kg total body water decrease by 1.1 kg despite this level of dehydration only 2 subjects experience thirst.
For alcohol some athletes mistake that, they replace fluid and load upon carbohydrates by drinking beer. 12-ounce beer provides 16 gram carbohydrate, that is one third of carbohydrate in a glass of orange juice the same size. In addition to carbohydrates, beer also contains alcohol. Energy from alcohol breakdown generates heat, but does not fuel muscles work because alcohol is metabolized in the liver. It is hard to overstate alcohol's detrimental effect on physical activity. Alcohol is a diuretic that impairs the body's fluid balance making dehydration likely after exercise a person needs to replace fluid not lose them by drinking beer. Alcohol impairs the body's ability to regulate temperature making hypothermia or heat stroke more likely.
Alcohol also alters perceptions, slows reaction time, reduces strength, power and endurance and hinders accuracy, balance, eye - hand coordination and coordination in general all opposing optimal athletic performance. In addition, it deprives people of their judgment thereby compromising their safety in sports related fatalities and injuries involving alcohol and other drugs. Clearly alcohol impairs performance, but physically active people do drink on occasion.