Specially designed sports drinks are intended to help athletes and games professionals to recoup the fluid loss and achieve fast recovery of the fatigued muscles. They are supposed to replenish the electrolytes, carbohydrates and other nutrients lost through sweating the body during exercise. Electrolyte replacement promotes proper re-hydration, critical to delay the onset of fatigue and carbohydrates are important in enhancing performance. There are isotonic, hyper tonic and hypo tonic types of sports drinks, though most athletes prefer isotonic drinks as they are similar to body fluids in terms of tonicity, containing about 13-19 gm sugar per an 8 oz serving. Many soft drinks can serve as sports drink as they are also more or less isotonic but without some of the special nutrients added to the latter during manufacture.
Why sports drinks? Why not water? Many may be wondering if water can do the job for people in tropical climates for quenching their thirst, why athletes cannot take water to compensate for water loss through perspiration. Some believe that taking 4-6 oz of water for every 15-20 minutes exercise should be adequate for making up water loss. But along with water, body also loses electrolytes like chloride, calcium, magnesium, sodium and potassium which if not compensated can be harmful. Electrolytes control osmosis of water between the body compartments and maintain acid-base balance. Sodium and potassium will reduce urine output, enable fluid to empty quickly from the stomach, promote absorption from GI tract and encourage fluid retention. Generally sports drinks do not hydrate better than what just plain water does but presence of flavor and good taste makes one drink more. During exercise there is increased uptake of blood glucose by muscles which is compensated by the liver which provides glucose from glycogen and lactate.
Energy drinks and sports drinks are relatively new to India but their market is estimated to be of the order of Rs 500 crore and knowledgeable pundits feel it could double in the next 2 years. Whether this will turn out to be true remains to be seen in this country dominated by 'nimbu pani' and an assortment of traditional thirst quenchers. The recent emphatic claims that chocolate flavored milk can be as effective as, if not better than, most expensive sports drinks in the market are bound to damage the prospects of this particular industry which is in its nascent stage in the country. According to a few scientific studies, those drinking chocolate milk were found to have significantly lower levels of creatinine kinase which is an indicator of muscle damage. Added to this, cocoa and milk have a plethora of nutrients not found in sports drinks. Mix of high quality protein and carbohydrate in milk is believed to be ideal in refueling exhausted muscles after a rigorous workout. Milk also provides minerals like calcium, potassium and magnesium that, both recreational exercisers and elite athletes, need to replace after strenuous activity. Many studies involving athletes, cyclists, foot ballers and others have confirmed the effectiveness of milk to combat muscle fatigue after their physical activity. Sports drinks are also affected by the adverse publicity linking their consumption to tooth erosion.
Ultimate choice vis-a-vis consuming post-exercise drinks will depend on the consumer. It is felt that a lean person, not vulnerable to put on weight, can opt for flavored milk which gives 226 kC and 32 gm of sugar per serving of 8 oz (whole milk) or 158 kC and 24 gm of sugar (skimmed milk). In contrast a sports drink contributes to only 50 kC and 13-15 gm of sugar and heavily built consumers may be better off with these products to guard against putting on unwanted weight. For normal people going through light impact activities like short run, walking, garden work, swimming etc, of less than 60 minutes duration, consumption of plain water is considered good enough for re-hydration. Choice is yours!