Daily water needs
• Urine – 1.2 litres
• Feaces – 0.75 litres
• Skin evaporation – 0.4 litres
• Respiration – 0.15 litres
• Total – 2.5 litres
An hour of exercise uses another 1-2 litres of water, depending on training intensity and weather conditions. If you eat enough vegetables and fruit, you can get from them 1-1.5 litres of water per day. Diets low on fruit and vegetables provide only about 0.3 litres of water each day. As the actual daily water needs are difficult to estimate, I advise to consume water by small quantities but frequently throughout a day. Basically, just keep sipping water, including the time when you are in a gym. You should not worry about consuming too much water as the body simply excretes any access, while your daily water needs are met. Only in extreme cases drinking too much water can have serious complications (something like running a marathon in very high temperatures and humidity without electrolyte (sodium) replacement can cause blood thinning). On the other hand, dehydration can cause a decrease of your training performance and often is the reason of annoying head-aches. You can easily assess your hydration levels by urine colour:
• Clear – hydrated
• Very pale yellow – hydrated
• Pale yellow – hydrated
• Yellow – mild dehydration
• Dark yellow – dehydration
Sports drinks, in my opinion, should be called sugar drinks. They fall into 3 categories:
• Hypertonic – more than 8 g of glucose and/or maltodextrin/100 ml. As hypertonic drinks contain more glucose than body fluids, absorption from the gut and rehydration is slower than if you drink just water.
• Isotonic drinks contain the same amount of glucose as body fluids – 4-8 g of glucose/100 ml, therefore absorption from the gut and rehydration is faster in comparison to drinking pure water.
• Hypotonic drinks contain less glucose than body fluids – less than 4 g of glucose/100 ml. Such drinks are also absorbed from the gut and rehydrate body faster than water on its own.
Sports drinks are not suitable for fat loss diets. If you are on maintenance or muscle gain diet and you feel the need for extra energy from sports drinks, make sure you in-calculate to your diet calories coming from the sugar.
Natural diuretics that encourage water loss from the body: coffee, tea, cola and other drinks that contain caffeine, also – alcohol. By the way, 1 g of alcohol has almost the same amount of calories as fat – 7 kcal.