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Lopez et al. 2009: Creatine and Hydration Status

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Study Overview

Citation: Lopez RM, Casa DJ, McDermott BP, Ganio MS, Armstrong LE, Maresh CM. (2009). Does creatine supplementation hinder exercise heat tolerance or hydration status?

A systematic review with meta-analyses. Journal of Athletic Training, 44(2), 215-223.

This systematic review with meta-analyses directly addresses one of the most persistent myths in sports nutrition: that creatine causes dehydration and heat intolerance.

The findings conclusively debunk this myth.

The creatine-dehydration myth — creatine actually improves hydration status

Study Design and Methods

Lopez and colleagues from the University of Connecticut conducted a systematic review of all available studies examining creatine’s effects on hydration status and heat tolerance.

They searched multiple databases for studies measuring total body water, fluid distribution, thermoregulation, sweat rate, and exercise heat tolerance in creatine-supplemented versus non-supplemented individuals.

Key Findings

Creatine Improves Hydration

The meta-analysis found that creatine supplementation actually increases total body water.

This is because creatine acts as an osmolyte — it draws water into muscle cells (intracellular water retention).

This is a beneficial effect, not harmful, as it increases the body’s water reserves and supports cellular function.

Total body water status in creatine-supplemented individuals compared to control groups

No Heat Intolerance

There was no evidence that creatine supplementation impairs thermoregulation or increases the risk of heat-related illness during exercise.

In fact, by increasing total body water, creatine may provide a slight buffer against dehydration during prolonged exercise in the heat.

No Increased Cramping Risk

The review found no evidence supporting the claim that creatine increases muscle cramping.

The mechanism for creatine-related cramping has never been established, and observational data from athletic populations using creatine does not show increased cramping rates.

(Kreider et al., 2017)

Origin of the Dehydration Myth

The myth likely originated from two misunderstandings. First, early observations that creatine increases body weight led to assumptions about water balance.

Second, a few anecdotal reports from athletes who experienced cramping while using creatine were attributed to the supplement without controlling for other factors (inadequate hydration, electrolyte imbalance, overtraining).

The irony is that creatine does increase water in the body — but inside muscle cells, which is beneficial.

Intracellular hydration supports muscle function, protein synthesis, and overall performance.

Practical Implications

  1. Creatine does not cause dehydration — This myth should be retired
  2. Normal hydration practices are sufficient — No special water intake protocol is needed
  3. Safe for hot climates — No increased risk of heat illness
  4. Safe for endurance exercise — No evidence of cramping risk
  5. May actually help — Increased intracellular water may buffer against dehydration

Malaysian Relevance

This finding is particularly important for athletes in tropical Malaysia where temperatures regularly exceed 30 degrees Celsius with high humidity.

Malaysian athletes, outdoor workers, and gym-goers can confidently use creatine without fear of dehydration — in fact, the increased total body water may be an advantage in Malaysia’s hot climate.

Typical Malaysian temperatures — creatine remains safe and may even help in hot conditions

Where This Fits in the Evidence

Lopez et al. (2009) is not a single trial but a systematic review with meta-analyses, which is why it carries more weight than the anecdotes it overturns. Pooling the available hydration and heat-tolerance studies, it found creatine raises total body water rather than depleting it, with no signal of impaired thermoregulation or increased cramping. That places the dehydration myth firmly on the wrong side of the evidence — a conclusion the ISSN position stand echoes. The wider safety literature is collected in our research library.

Sources and References

  • Lopez RM, et al. (2009). Does creatine supplementation hinder exercise heat tolerance or hydration status? JAT, 44(2), 215-223.
  • Kreider RB, et al. (2017). ISSN position stand. JISSN, 14, 18.

Further Reading

Sources & References

Full citations available in our Research Library.

References

  1. Lopez RM, Casa DJ, McDermott BP, Ganio MS, Armstrong LE, Maresh CM. (2009). Does creatine supplementation hinder exercise heat tolerance or hydration status? A systematic review with meta-analyses. *Journal of Athletic Training*. doi:10.4085/1062-6050-44.2.215 PubMed
  2. Kreider RB, Kalman DS, Antonio J, Ziegenfuss TN, Wildman R, Collins R, Candow DG, Kleiner SM, Almada AL, Lopez HL. (2017). International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. *Journal of the International Society of Sports Nutrition*. doi:10.1186/s12970-017-0173-z PubMed

Frequently Asked Questions

Does creatine cause dehydration?

No. Lopez 2009 showed creatine actually improves total body water and hydration status. The dehydration myth is one of the most persistent and incorrect beliefs about creatine.

Does creatine increase water retention?

Yes, but this is intracellular water retention — water stored inside muscle cells. This is beneficial, not harmful, and actually improves hydration status.

Should I drink more water when taking creatine?

Maintaining good hydration is always important, but creatine does not cause dehydration. Follow normal hydration guidelines — approximately 2-3 litres daily, more in hot climates like Malaysia.

This content is for educational purposes only and is not medical advice. Consult a healthcare provider before starting any supplementation.

Reviewed by T. Dinaiz, BSc (Molecular Biology), MSc (Biotechnology)

Reviewed against peer-reviewed research · Our editorial policy