Water plays a fundamental role in maintaining human health, as it represents a major component of the body and is involved in numerous physiological processes. It contributes to temperature regulation, nutrient transport, metabolic reactions, and the elimination of waste products through perspiration and urine. Proper hydration is therefore essential not only for athletic performance, but also for overall health and wellbeing (Thomas et al., 2016).

Daily hydration requirements vary depending on age, sex, climate, and level of physical activity. In general, adults are encouraged to consume adequate amounts of fluids throughout the day, coming not only from drinking water but also from foods and other beverages.

Water remains the primary source of hydration, but isotonic drinks are frequently used in sports and endurance activities because they also contain carbohydrates and electrolytes such as sodium and potassium. These components help replace nutrients lost through sweating and may support energy availability during prolonged exercise (Maughan, 2004). Most isotonic beverages contain approximately 6–8% carbohydrates, usually in the form of glucose, fructose, or sucrose, which allows for relatively rapid absorption and energy supply during exercise (Jeukendrup et al., 1997).

Research suggests that isotonic drinks can improve hydration and physical performance during long-duration or high-intensity activities, particularly in endurance and intermittent sports such as running, cycling, football, basketball, or rugby (Baker et al., 2015; Jeukendrup, 2011). Carbohydrate-electrolyte beverages may help maintain glycogen stores, delay fatigue, and support electrolyte balance, which is important for proper muscle function and exercise capacity (Jensen & Richter, 2012).

However, isotonic drinks are not necessary for everyone. For individuals performing light or moderate physical activity lasting less than one hour, water is generally sufficient to maintain hydration (Thomas et al., 2016). Similarly, people engaged mainly in recreational fitness or strength training may experience limited additional benefits from sports drinks (Escobar et al., 2019). In some situations, regular consumption of isotonic beverages may also contribute unnecessary caloric intake, which could negatively influence weight-management goals (Dragusin & Horswill, 2019).

Other beverages may also contribute effectively to hydration. Research on beverage hydration has shown that drinks such as milk, fruit juices, and oral rehydration solutions can sometimes provide equal or even superior rehydration effects compared to standard sports drinks because of their electrolyte composition (Maughan et al., 2016). Furthermore, moderate coffee consumption does not appear to cause dehydration in habitual coffee drinkers, contrary to common belief (Killer et al., 2014). Palatability is another important factor, as pleasant-tasting beverages may encourage individuals to drink larger volumes of fluids during exercise (Passe et al., 2000).

In conclusion, isotonic drinks may represent a useful hydration strategy for athletes involved in prolonged or intense physical exercise. Nevertheless, for most people engaging in moderate daily activity, water remains the simplest, healthiest, and most appropriate hydration option. Fluid intake should always be adapted to the intensity and duration of exercise, environmental conditions, and individual health objectives.

References

Baker, L. B., Rollo, I., Stein, K. W., & Jeukendrup, A. E. (2015). Acute effects of carbohydrate supplementation on intermittent sports performance.

Dragusin, I. B., & Horswill, C. A. (2019). Does sport-drink use during exercise promote an acute positive energy balance?

Escobar, K. A., VanDusseldorp, T. A., & Kerksick, C. M. (2019). Carbohydrate intake and resistance-based exercise: Are current recommendations reflective of actual need?

Jeukendrup, A. E. (2011). Nutrition for endurance sports: marathon, triathlon, and road cycling.

Jeukendrup, A., Brouns, F., Wagenmakers, A. J., & Saris, W. H. (1997). Carbohydrate-electrolyte feedings improve 1 h time trial cycling performance.

Killer, S. C., Blannin, A. K., & Jeukendrup, A. E. (2014). No evidence of dehydration with moderate daily coffee intake: A counterbalanced cross-over study in a free-living population.

Maughan, R. J. (2004). The sports drink as a functional food: formulations for successful performance.

Maughan, R. J., Watson, P., Cordery, P. A., Walsh, N. P., Oliver, S. J., Dolci, A., Rodriguez-Sanchez, N., & Galloway, S. D. (2016). A randomized trial to assess the potential of different beverages to affect hydration status: Development of a beverage hydration index.

Passe, D. H., Horn, M., Stofan, J., & Murray, R. (2000). Palatability and voluntary intake of sports beverages, diluted orange juice, and water during exercise.

Thomas, D. T., Erdman, K. A., & Burke, L. M. (2016). Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and athletic performance.