填空题 For most average exercisers and athletes, sports drinks are not only a waste of your money, but more importantly, can actually worsen the health of most who use them. Less than one percent of those who use sports drinks actually benefit from them. Most sports drinks are loaded with things you DON'T want, like refined sugars, artificial colors and chemicals, none of which are in natural coconut water, which is a clear, light, refreshing liquid (95 percent water) extracted from young, green coconuts that have not reached maturity.
If you exercise for 30 minutes a day at a moderate to high intensity, fresh, pure water is the best thing to help you stay hydrated. It's only when you've been exercising for longer periods, such as for more than 60 minutes, or in the heat, or at extreme intensity levels, where you are sweating profusely, that you may need something more than water to replenish your body in order to keep your body's proper electrolyte balance. If your electrolytes fall out of balance, you can suffer severe medical problems. That is because electrolytes are inorganic compounds that become ions in solution and have the capacity to conduct electricity. They are important for electrical signaling-and of course your brain, heart, muscles and nervous system are all bioelectrical systems.
Besides plain water, coconut water is one of the best and safest options to rehydrate yourself after a strenuous workout. If you need the electrolytes, it will provide them. If you don't need them, then it certainly won't hurt you. And as you're learning, coconut water has a mountain of other health benefits in addition to rehydration, which no commercial sports drink in the world can provide. Depending on how much salt you've lost through sweating, you might even add a tiny pinch of natural Himalayan salt to your glass of coconut water.
One study in 2007 found sodium-enriched coconut water to be as effective as commercial sports drinks for whole body rehydration after exercise, with less stomach upset.
Coconut water is sterile when it comes out of the coconut, and extremely similar in composition to human blood plasma. These unique properties make it so completely compatible with the human body that it can be infused intravenously into your bloodstream. Physicians have actually used coconut water successfully as an intravenous fluid for more than 60 years, especially in remote regions of the world where medical supplies are limited and it has saved many lives. You can appreciate how safe and beneficial this natural beverage is, if it can be used intravenously!

单选题 During heavy exercise, electrolytes are lost in sweat. These electrolytes must be ______ to keep the electrolyte concentrations of the body fluids constant.
A. retained B. reduced C. returned D. replaced

单选题 Coconut water is a natural isotonic beverage, with the same level of ______ as we have in our blood.
A. medical saline B. electrolyte balance
C. blood plasma D. intravenous fluid

填空题 Most sports drinks are just another industry wheeze, with the unwanted junk and unnecessary ingredients such as ______.

填空题 Water is generally sufficient for ______, but for longer sessions, such as for more than 60 minutes, or at extreme intensity levels, an isotonic sports drink is recommended.

填空题 It is more than 60 years that coconut water has been used as ______ in some developing countries where medical supplies are limited.