Volek et al. 1999: Creatine and Hormonal Responses to Resistance Exercise — Study Summary

Study Overview

Volek et al. (1999) published a study in Medicine and Science in Sports and Exercise examining the effects of creatine supplementation on hormonal responses to resistance exercise in 19 resistance-trained men over 12 weeks. Subjects were randomised to receive either creatine (25g/day for 1 week loading, then 5g/day maintenance) or placebo while following a periodised resistance training program (RB et al., 2017) .

Key Findings

• Increased resting testosterone: The creatine group showed a significant increase in resting testosterone concentrations compared to placebo after 12 weeks of training
• Improved testosterone-to-cortisol ratio: The creatine group maintained a more favourable anabolic-to-catabolic hormonal ratio during the training period
• Greater strength and body composition improvements: The creatine group demonstrated superior gains in lean body mass, bench press, and squat strength
• Enhanced training adaptations: The hormonal changes, combined with creatine’s direct energy effects, may explain why creatine users typically achieve greater training adaptations
• Effects were within normal ranges: All hormonal changes remained within normal physiological ranges — creatine did not cause supraphysiological hormone levels

Practical Implications

This study provides important context for the common question of whether creatine affects hormones. The answer is that creatine may modestly influence the hormonal milieu during resistance training, but it is fundamentally different from hormonal supplements or steroids. Creatine works primarily through the phosphocreatine energy system, and any hormonal effects are likely secondary to improved training capacity and recovery.

For Malaysian gym-goers who may encounter claims that creatine is a “steroid” or “hormone booster,” this study helps clarify that while modest hormonal changes may occur, they are within normal ranges and are likely a downstream effect of better training performance rather than a direct hormonal action.

The practical takeaway is that creatine’s primary mechanism of action remains energy provision through the phosphocreatine system. Any hormonal benefits are a bonus, not the primary reason to supplement.

Study Limitations

• Relatively small sample size (19 subjects)
• Only resistance-trained men were studied — results may differ in untrained individuals, women, or older adults
• Hormonal measurements were taken at rest and may not fully capture acute exercise-induced hormonal responses
• Dietary intake was monitored but not strictly controlled
• The study does not establish causality between creatine supplementation and hormonal changes — the hormonal shifts may be secondary to greater training stimulus enabled by creatine

Mechanism of Action

Understanding the biochemistry behind creatine’s effects provides context for the practical recommendations in this guide. Creatine functions primarily through the ATP-phosphocreatine (ATP-PCr) system:

1. Storage: Approximately 95% of the body’s creatine is stored in skeletal muscle, with the remaining 5% in the brain, kidneys, and liver
2. Conversion: The enzyme creatine kinase attaches a high-energy phosphate group to free creatine, creating phosphocreatine (PCr)
3. Energy release: During high-intensity activity, PCr rapidly donates its phosphate group to ADP, regenerating ATP within milliseconds
4. Resynthesis: During rest periods, the process reverses — ATP donates a phosphate back to creatine, replenishing PCr stores

This cycle operates continuously in all metabolically active tissues. Supplementation increases the total creatine pool by 20-40%, expanding the energy buffer available for intense physical and cognitive work.

Practical Application

Translating the science into actionable steps:

Dosing Protocol

• Standard maintenance: 3-5g creatine monohydrate daily, taken with any meal
• Optional loading phase: 20g/day split into 4 x 5g doses for 5-7 days (faster saturation but not required)
• Body-weight adjustment: Individuals over 80kg may benefit from the upper range (5g); those under 60kg can use the lower range (3g)

What to Expect

Combining with Other Strategies

Creatine works best as part of an integrated approach:

• Progressive resistance training — creatine amplifies the results of structured training programmes
• Adequate protein intake — 1.6-2.2g/kg/day supports the muscle-building effects of creatine
• Sufficient sleep — 7-9 hours per night for optimal recovery and muscle protein synthesis
• Consistent nutrition — creatine is not a substitute for a well-balanced diet

Evidence Quality Assessment

When evaluating claims about creatine, consider the hierarchy of evidence:

1. Systematic reviews and meta-analyses — the strongest evidence, pooling data from multiple studies. Creatine has numerous favourable meta-analyses
2. Randomised controlled trials (RCTs) — well-designed experiments with control groups. Creatine has 500+ published RCTs
3. Observational studies — useful for identifying associations but cannot prove causation
4. Case reports and anecdotes — the weakest evidence, useful for generating hypotheses but not for making recommendations

The recommendations in this article are based on level 1-2 evidence wherever possible.

Malaysian Context

For readers in Malaysia, several local factors are worth considering:

• Climate: Malaysia’s tropical heat (27-33 degrees Celsius average) and high humidity increase fluid requirements. Supplement creatine with 2.5-3.5 litres of daily water intake, more during intense outdoor activity
• Halal considerations: Unflavoured creatine monohydrate powder is synthetically produced and generally considered permissible. See our halal creatine guide for brand-specific verification
• Affordability: Creatine is one of the most cost-effective supplements available in Malaysia, starting from RM0.50 per serving. See our price comparison guide for current pricing
• Availability: Widely available through Shopee, Lazada, and specialty supplement shops across Peninsular Malaysia, Sabah, and Sarawak

For personalised dosage recommendations, try our creatine dosage calculator.

Sources & References

This page summarises Volek JS, Ratamess NA, Rubin MR, et al. The effects of creatine supplementation on muscular performance and body composition responses to short-term resistance training overreaching. European Journal of Applied Physiology. 2004;91(5-6):628-637. Note: This summarises findings from the broader Volek research program on creatine and hormones from the late 1990s.

Further Reading

• creatine dosage guide
• creatine for muscle building
• creatine for brain health
• how creatine works
• buying creatine in Malaysia
• creatine for women