Benefits
Rehydration after exercise
In three small crossover trials in active adults who lost about 2 to 3% of body weight through exercise, coconut water restored body weight and fluid balance about as well as a carbohydrate-electrolyte sports drink, and in two of them about as well as plain water. It was not better than the sports drink. One of the trials was funded by a coconut water brand.
High potassium content
A cup of coconut water provides roughly 400 mg (packaged, unsweetened) to 600 mg (fresh) of potassium, a useful share of the adequate intake of 3,400 mg a day for men and 2,600 mg for women. It is a convenient drink for adding potassium to the diet, but people with kidney problems or on potassium-raising medicines should limit large amounts.
Endurance exercise hydration
In 19 experienced cyclists, drinking coconut water instead of an equal-calorie sports drink during a 90-minute ride gave the same 20 km time trial performance, heart rate and sweat loss. Its sodium content is lower and varies by brand, so long or very sweaty sessions may call for added salt.
Stomach comfort while rehydrating
In one trial, fresh coconut water caused less nausea and fullness than a sports drink or water and was easier to drink in large amounts. In another, funded by a coconut water brand, participants felt more bloated and had more stomach upset with coconut water. Tolerance seems to vary by person and product.
Mechanism of action
Potassium-rich electrolyte mix
Coconut water is much higher in potassium than in sodium. Fresh coconut water has about 250 mg potassium and 105 mg sodium per 100 g; packaged unsweetened versions have about 165 mg and 26 mg. In one rehydration trial, coconut water needed added sodium before it beat plain water significantly.
Natural sugars
A cup contains roughly 6 to 10 g of natural sugars. In the rehydration trials, blood glucose rose with coconut water and with sports drinks but not with plain water, and in a cycling trial blood glucose ran slightly lower with coconut water than with a sports drink.
Clinical trials
Randomized, single-blind crossover comparing bottled water, pure coconut water (VitaCoco), coconut water from concentrate and a carbohydrate-electrolyte sports drink. Funded by VitaCoco. (Kalman et al. 2012, J Int Soc Sports Nutr)
12 exercise-trained men who lost about 2% of body weight in 60 minutes of treadmill exercise.
All four drinks restored hydration similarly, with no differences in fluid retention or later treadmill time to exhaustion. Participants felt more bloated and had more stomach upset with both coconut waters.
Randomized crossover comparing fresh young coconut water, a carbohydrate-electrolyte drink and plain water over a 2-hour recovery. (Saat et al. 2002, J Physiol Anthropol Appl Human Sci)
8 healthy men who lost about 2.8% of body weight exercising in the heat.
Weight regained was 75% with coconut water, 80% with the sports drink and 73% with water, with no significant differences. Blood sodium, chloride and osmolality did not differ. Coconut water caused less nausea and fullness and was easier to drink in large amounts.
Crossover comparing plain water, a sports drink, fresh young coconut water and sodium-enriched coconut water over a 2-hour recovery. (Ismail et al. 2007, Southeast Asian J Trop Med Public Health)
10 healthy men who lost about 3% of body weight running in the heat.
Rehydration was 58% with water, 65% with plain coconut water, 68% with the sports drink and 69% with sodium-enriched coconut water; only the sports drink and the sodium-enriched version were significantly better than water. Plasma volume recovered with all three non-water drinks. The sodium-enriched version caused less nausea and stomach upset than water or the sports drink.
Randomized crossover comparing coconut water with an equal-calorie commercial sports drink during 90 minutes of cycling at 70% of peak power, followed by a 20 km time trial. (O'Brien et al. 2023, Sports (Basel))
19 experienced cyclists (15 men, 4 women).
There were no significant differences in time trial performance, power, heart rate, sweat loss or other measures. Blood glucose was slightly lower with coconut water.