Isotonic Drinks & Gels: What the Science Actually Shows
Isotonic drinks and gels are among the most widely used sports supplements in endurance athletics. Their core purpose is straightforward: deliver carbohydrates and electrolytes quickly and in an easily absorbed form during exercise. But is the evidence for their benefits as solid as the marketing suggests?
Primary Evidenced Benefits
The strongest evidence supports isotonic drinks for maintaining athletic performance during prolonged exercise. Sodium- and potassium-containing drinks slow the risk of hyponatraemia during very long efforts. Carbohydrate-containing gels deliver fast glucose that working muscles need in the later stages of a session.
OstroVit Isotonic Drink 1500g Pirn and PowerBar Iso Active 600g Sidrun are good examples of products combining both electrolytes and carbohydrates in a single serving β available at maxfit.ee.
One meta-analysis found that carbohydrate ingestion during exercise improves endurance performance compared with water alone (Jeukendrup & Chambers, 2010).
Secondary and Emerging Effects
Some studies suggest that mouth rinsing with a carbohydrate solution β without swallowing β may improve performance in shorter high-intensity sessions, likely through a brain-mediated mechanism (Chambers et al., 2009). This is an interesting finding, but its practical application for everyday athletes remains limited.
Electrolytes may help prevent muscle cramps during prolonged exertion, although the precise mechanism of exercise-induced cramping is still being studied.
Where the Evidence is Weak
For short sessions under 60 minutes, most research shows no clear advantage of isotonic drinks over plain water. That said, there is also no evidence of harm β the question is mainly one of need versus cost.
Many popular gels contain colorants and flavorings with limited long-term study data, though no short-term safety signals have been reported.
Who Gains Most
- Endurance athletes training for over 60β90 minutes per session
- Marathon runners and triathletes who want to avoid energy dips
- Athletes training in hot conditions with high sweat rates
- People who train fasted in the morning
OstroVit Isotonic 500g Apelsin is a practical single-serving option for sessions lasting over 45 minutes.
Realistic Expectations
Isotonic drinks and gels are not miracle products β they complement solid nutrition and hydration habits rather than replacing them. For the recreational athlete whose sessions are under 60 minutes, water is usually sufficient. For longer efforts, replenishing carbohydrates and electrolytes becomes meaningfully relevant for sustaining performance.
FAQ
Can isotonic drinks be consumed daily?
Regular use is safe, but these products contain sugars and calories. Non-athletes do not need them on ordinary days β water serves the same hydration purpose without the extra calories.
What is the difference between isotonic drinks and energy drinks?
Isotonic drinks are designed to support hydration and carbohydrate replenishment during exercise. Energy drinks contain caffeine and other stimulants and serve a different purpose.
When should I take a gel during training?
Most guidelines recommend taking a gel every 30β45 minutes during long endurance sessions, always consumed with adequate water.
References
Jeukendrup, A. E., & Chambers, E. S. (2010). Oral carbohydrate sensing and exercise performance. Current Opinion in Clinical Nutrition and Metabolic Care, 13(4), 447β451. https://pubmed.ncbi.nlm.nih.gov/20453646/
Chambers, E. S., Bridge, M. W., & Jones, D. A. (2009). Carbohydrate sensing in the human mouth: effects on exercise performance and brain activity. The Journal of Physiology, 587(8), 1779β1794. https://pubmed.ncbi.nlm.nih.gov/19237430/
Maughan, R. J., & Shirreffs, S. M. (2010). Development of hydration strategies to optimize performance for athletes in high-intensity sports and in sports with repeated intense efforts. Scandinavian Journal of Medicine & Science in Sports, 20(Suppl 2), 59β69. https://pubmed.ncbi.nlm.nih.gov/20840563/
