Drink, Don’t Drain
PREVENT A PERFORMANCE MELTDOWN BY PICKING THE RIGHT BEVERAGE FOR YOUR HYDRATION NEEDS.
In bold, bright lettering, a bottle exclaims “Quench your thirst!” from a supermarket shelf. Another brand claims to “hydrate better than water”. Inundated with a litany of drinks that promise effective rehydration, how can you tell the products that work from the ones that sabotage your efforts? When picking the right drink, observe how much you’re sweating. “You lose both water and electrolytes when you sweat,” says Dr Joanna Tan, senior dietician at Changi General Hospital. “Besides exercise intensity being a factor in sweat rates, active and physically fit individuals also tend to perspire less for a given activity, as their metabolic mechanism is more efficient.” So if you’re just returning to the gym or the track after a lay-off, you might have a bigger need for electrolytes. In making up for your lost ions, pay most attention to sodium. It exists as the majority of electrolytes in body plasma and performs the primary function of rehydration. “Sodium in fluid promotes both carb and water uptake in the intestines, helps cells retain water and stimulates thirst,” she says. By knowing our body’s needs, we can determine which of these five drinks you should be gulping down.
Sports drinks Also called isotonic drinks, these are the most powerful fluid replenishers, boasting a concentration of particles (osmolality) that mirror that of blood. “They replace fluids lost at an optimum rate, while supplying a carbohydrate boost to make up for depleted glycogen stores,” states Dr Frankie Tan, head and senior sports physiologist at the Singapore Sports Institute. For the optimum amount of sodium in a sports beverage, he recommends 40mg to 50mg for every 100ml.
Ideally, the percentage of carbs in isotonic drinks should be in the range of 4 to 8 per cent, says Dr Joanna Tan. This translates to 8g of carbohydrate per 100ml serving, or 2g every 100 calories. Any higher and the drink might instead further dehydrate the body while causing carb-induced distress such as nausea.
Water This alone is sufficient to replenish fluid loss for light to moderate exercises of less than 60 minutes, says Dr Joanna Tan. You can also pair water with a source of carbohydrate – an energy bar, for example – to sustain performance in higher-intensity exercises of up to one hour.
For workouts lasting more than 60 minutes, she says: “Rehydration with water alone will dilute the blood rapidly, cause heat cramping due to sodium losses and increase fluid deficit through urine.”
However, you can drink water to rehydrate after intensive exercise as long as you also consume food. Besides being able to hold more sodium than beverages while still remaining palatable, the sodium and carbohydrate content in solid food can also assist in the uptake of water, adds Dr Frankie Tan.
Coconut water We’re no longer confined to sipping pure coconut juice from the actual fruit, as the drink is now widely sold in conveniently packaged “tetra paks”. This natural beverage contains about 5g of carbs and 25mg of sodium for every 100ml. In theory, as pure coconut water has a lower concentration of both carbohydrate and sodium than sports drinks, it’s not as rapidly absorbed as the latter.
While a study published in Medicine & Science In Sports & Exercise showed coconut water replaces body fluids as effectively as a typical sports beverage (and slightly better than water), the results apply only to light exercise. Dr Frankie Tan also warns that drinking coconut water can upset the stomach.
There’s a clear- cut benefit to this fluid, though: It contains an abundance of heart-healthy potassium ions, as well as a dose of antioxidants that can combat the free radicals produced during physical exertion.
Fruit juice These have a higher carb and lower sodium content compared to sports drinks. “Their higher osmolality also affects the rate of fluid absorption, while the high fructose amount may cause stomach discomfort,” says Huang Liyan, sports dietician at the Singapore Sports Institute.
Energy drinks These contain additives – such as taurine and caffeine – that aim to provide drinkers with the perception of alertness. As many energy drink brands also market themselves as ideal fluids for athletes, they can easily be mistaken for sports drinks.
To identify such, read the nutritional label. At 11g to 15g per 100ml, the carb content of these beverages is too high to benefit physical performance, say our medical experts. “Energy drinks may cause even further dehydration, as the liquids move from cells into intestine, instead of the reverse,” warns Liyan.