Are we being drowned by overhydration advice on the Internet?

ABSTRACT

Objective: Because inappropriate recommendations about hydration during exercise appear widespread and potentially dangerous, we assessed the quality of a sampling of information currently available to the public on the Internet.

Methods: Internet searches using the Google search engine were conducted using the terms “hydration,” “hydration guidelines,” “drinking fluids” and “drinking guidelines” combined with “and exercise.” From the first 50 websites for each search phrase, duplicates were removed yielding 141 unique websites that were categorized by source and examined for specific hydration related information and recommendations.

Results: Correct endorsement was as follows (reported as percent endorsing the concept relative to the number of websites addressing the issue): some weight loss should be expected during exercise (69.5% of 95), fluid consumption during exercise should be based upon thirst (7.3% of 110), electrolyte intake is not generally necessary during exercise (10.4% of 106), dehydration is not generally a cause of heat illness (3.4% of 58) or exercise-associated muscle cramping (2.4% of 42), exercise-associated muscle cramping is not generally related to electrolyte loss (0.0% of 16), and overhydration is a risk for hyponatremia (100.0% of 61). Comparison of website information from medical or scientific sources with that from other sources revealed no differences (p = 0.4 to 1.0) in the frequency of correct endorsement of the examined criteria.

Conclusion: Prevalent misinformation on the Internet about hydration needs during exercise and the contribution of hydration status to the development of heat illness and muscle cramping fosters overhydration. In general, those websites that should be most trusted by the public were no better than other websites at providing accurate information, and the potential risk of hyponatremia from overhydration was noted by less than half the websites. Since deaths from exercise-associated hyponatremia should be preventable through avoidance of overhydration, dissemination of a more appropriate hydration message is important.

KEYWORDS:

• Dehydration
• exercise
• hyponatremia
• sodium
• water-electrolyte imbalance

Acknowledgments

This material is the result of work supported with resources and the use of facilities at the VA Northern California Health Care System. The contents reported here do not represent the views of the Department of Veterans Affairs or the United States Government.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Funding

This article has received no external funding.