Fruit Juice vs Sports Drinks: Which Rehydrates You Better Post-Exercise?
Could a glass of fruit juice be just as effective as a sports drink to rehydrate after exercise? A 2026 study compared a 100% fruit juice blend with a glucose-based sports drink and water after participants exercised in the heat and became dehydrated.
The researchers found no significant differences between the three drinks in their main measures of rehydration. However, the blood glucose responses were quite different, and three participants experienced diarrhoea after drinking the juice. Here's what the study found, and what it might mean if you're choosing a drink after exercise.
Key findings: 60-second read
- Similar rehydration results: The study found no significant differences between fruit juice, a sports drink and water for net water balance, urine volume or water retention.
- Different blood glucose responses: The sports drink produced the highest blood glucose response, followed by fruit juice and then water.
- Low blood glucose readings: At least one reading below the study's hypoglycaemia threshold was recorded in 75% of participants after water, 19% after fruit juice and none after the sports drink.
- Gut symptoms matter: Three participants were withdrawn after experiencing diarrhoea following the large volume of fruit juice.
- The practical message: This particular fruit juice blend may be an alternative for some people, but the study doesn't establish that juice is better than sports drinks or water for everyone.
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Why does rehydration matter after exercise?
When you exercise, particularly in hot conditions, your body loses fluid through sweat. If those losses aren't replaced, you can become dehydrated. Depending on the degree of fluid loss and the conditions, this can affect exercise performance, concentration, mood and your ability to regulate body temperature.
Water is often sufficient for replacing fluid after everyday exercise. Sports drinks add carbohydrates and electrolytes, particularly sodium, which can be useful during prolonged or demanding exercise and when substantial sweat losses need to be replaced.
Fruit juice is another possibility. It naturally contains carbohydrates and potassium, along with other nutrients. But does it actually help replace fluid as effectively as a sports drink?
What did the fruit juice rehydration study involve?
The study, published in the Journal of the International Society of Sports Nutrition in 2026, used a randomised cross-over design. Participants completed each of the three drink trials, allowing the researchers to compare how the same individuals responded to each beverage.
Seventeen healthy adults completed the study: 15 men and 2 women, with an average age of 28. Participants exercised in a hot environment until they had lost approximately 2% of their body mass through fluid loss.
The three drinks compared
- Fruit juice: A blend containing 76% watermelon, 20% pomegranate and 4% lime.
- Sports drink: A glucose-based commercial sports drink.
- Water: Plain drinking water.
After exercise, participants consumed enough of their allocated drink to provide a volume of water equivalent to 150% of the body mass they had lost. The drinks were consumed over one hour, and participants were then monitored for another four hours.
The researchers measured net water balance, urine production, water retention, blood glucose, thirst and gastrointestinal comfort.
An important detail: The study matched the amount of water supplied by each drink, rather than simply giving participants the same total volume of each beverage. This was intended to make the comparison of fluid replacement more meaningful.
Which drink rehydrated participants best?
The main finding was that the researchers did not detect statistically significant differences between the three drinks for net water balance, total urine volume or percentage of water retained.
In other words, under the conditions of this experiment, the fruit juice, sports drink and water produced broadly similar rehydration results.
Rehydration results
| Measure | Fruit juice | Sports drink | Water |
|---|---|---|---|
| Total urine volume | 1,266 mL | 1,338 mL | 1,394 mL |
| Water retention | 42% | 37% | 35% |
| Net water balance | No significant difference detected | No significant difference detected | No significant difference detected |
Values are group averages reported in the study. Differences in the main rehydration measures were not statistically significant.
The fruit juice group had the lowest average urine volume and highest average water retention, but those differences did not reach statistical significance. It's therefore potentially inaccurate to say that fruit juice rehydrated participants better than the other drinks.
This study did not detect a clear difference in the outcomes it measured.
How did fruit juice affect blood glucose compared with a sports drink?
This is where the researchers found more noticeable differences. The sports drink produced the highest blood glucose response, fruit juice produced an intermediate response, and water produced the lowest.
Despite having a similar carbohydrate content, the fruit juice and sports drink produced different blood glucose patterns. The researchers suggested that the types of carbohydrates in the drinks may help explain this difference.
Participants who recorded low or high blood glucose readings
| Blood glucose finding | Fruit juice | Sports drink | Water |
|---|---|---|---|
| At least one low reading | 19% | 0% | 75% |
| At least one high reading | 0% | 44% | 0% |
The study defined hypoglycaemia as a blood glucose reading below 3.9 mmol/L and hyperglycaemia as a reading above 7.8 mmol/L. Blood glucose data were available for 16 participants.
The researchers recorded at least one reading below 3.9 mmol/L in 12 participants after water, compared with three after fruit juice and none after the sports drink. Conversely, seven participants recorded a reading above 7.8 mmol/L after the sports drink, while none did after fruit juice or water.
The three drinks produced different blood glucose responses, even though their rehydration results were similar. The juice appeared to produce a middle-ground response in this particular experiment.
Did the fruit juice cause digestive problems?
There was an important downside. Three participants were withdrawn from the study after experiencing diarrhoea following the fruit juice trial.
The researchers suggested that the large fructose load may have contributed. Participants consumed approximately 2.3 litres of the juice over one hour, providing an estimated 136 grams of carbohydrate, including around 68 grams of fructose.
The study mentioned that when a large amount of fructose is consumed in a short period, some may not be absorbed in the small intestine. Furthermore, this may contribute to gastrointestinal symptoms, including bloating and diarrhoea. However, the study did not establish the exact cause of the symptoms.
Why this matters: The three participants who experienced diarrhoea were excluded from the final analysis of gastrointestinal comfort. This means the apparently similar comfort scores among the remaining participants don't tell the whole story about how well the juice was tolerated.
The authors suggested that future studies should spread fluid intake over a longer period and consider including food, which would better reflect how people typically rehydrate after exercise.
What are the limitations of the study?
The study had a useful cross-over design, but there are several reasons to be cautious when applying its findings more broadly.
- Small sample: Only 17 participants completed the study, and 15 were men. The findings may not represent the responses of women or the wider population.
- Three withdrawals due to diarrhoea: These participants were unable to complete the fruit juice trial, which is relevant when considering the drink's gastrointestinal tolerance.
- Unusually large fluid intake: Participants consumed around 2.3 litres over one hour. This is not how many people would normally drink after exercise and may have contributed to the digestive symptoms.
- No food during the rehydration period: Participants remained in the laboratory without eating during the five-hour measurement period, which differs from typical post-exercise recovery.
- Limited real-world conditions: Participants exercised in a controlled laboratory setting and then rested. The findings may not translate directly to athletes continuing to train, work or move around after exercise.
- Unmeasured fluid losses: The researchers acknowledged that ongoing sweat and other fluid losses during the rehydration period were not included in their calculations.
There was also a relevant funding and disclosure detail. The study was supported through a partnership involving the University of Leicester and Innate-Essence Limited, the company that supplied the fruit juice. The authors reported that the company had no involvement in data collection, analysis or interpretation. This doesn't invalidate the findings, but it's useful context when assessing research.
So, is fruit juice a good alternative to sports drinks?
This study found that a particular 100% fruit juice blend produced similar rehydration results to a glucose-based sports drink and water after exercise-induced dehydration. The drinks did, however, produce different blood glucose responses.
The interesting takeaway is that a sports drink isn't necessarily the only way to replace fluid and carbohydrates after exercise. But the study was small, the fluid intake was unusually large, and some participants experienced significant digestive symptoms.
If you're interested in optimising your rehydration strategies post-exercise, it's best you seek professional assistance from your relevant health professionals.
- Grant
Frequently Asked Questions
Can fruit juice rehydrate you as well as a sports drink?
In this 2026 study, a specific watermelon, pomegranate and lime juice blend produced no significant differences from a glucose-based sports drink or water in the main measures of post-exercise rehydration. The result applies to the conditions and drinks tested, not necessarily every fruit juice or exercise situation.
Is water enough to rehydrate after exercise?
For many everyday exercise sessions, water alongside normal meals is sufficient. Longer or more intense exercise, heavy sweating and short recovery periods may increase the need to replace sodium and carbohydrates as well as fluid.
Why did some participants have low blood glucose after drinking water?
The study recorded blood glucose readings below 3.9 mmol/L in 12 of the 16 participants with glucose data after the water trial. Water contains no carbohydrate, but this finding does not mean water routinely causes clinical hypoglycaemia or that everyone needs a carbohydrate drink after exercise.
Why did fruit juice cause diarrhoea in some participants?
Three participants experienced diarrhoea after consuming a large volume of fruit juice over one hour. The researchers suggested that the high fructose intake may have contributed, although the exact cause was not established.
Is fruit juice better than a sports drink for blood glucose?
In this study, fruit juice produced a lower blood glucose response than the glucose-based sports drink. It also produced fewer readings above the study's hyperglycaemia threshold. This does not establish that fruit juice is the better choice for every athlete or recovery goal.
Should I replace sports drinks with fruit juice?
Not necessarily. Fruit juice may be an option for some people, but the right drink depends on exercise duration, sweat losses, carbohydrate and electrolyte needs, digestive tolerance and personal preference. This study alone is not enough to recommend a universal switch.
One key insight from this research
The three drinks produced similar results for the main measures of rehydration, but quite different blood glucose responses. Replacing fluid and supplying energy are related, but they aren't exactly the same thing.
Original research
Juett, L. A., van der Wolf-Ong, J., Gyamfi, P. A., Ebrahim, S. D., Codd, E. B., Pugh, C. F., Funnell, M. P., Hough, J., Varley, I., & Clayton, D. J. (2026). Post-exercise rehydration: a randomized cross-over trial comparing a 100% fruit juice, a glucose-based sports drink, and water. Journal of the International Society of Sports Nutrition.
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