Learning from Paul Greenhaff
The scientist who proved creatine works—and showed why it doesn't work for everyone
The Story
In the early 1990s, creatine was a mystery substance. Bodybuilders swore by it. Scientists weren't sure why it worked—or if it really did.
Paul Greenhaff, a professor at the University of Nottingham, set out to answer the question properly. Using muscle biopsies and precise measurements, he didn't just confirm that creatine works—he figured out why it works, how to make it work better, and why it fails for some people.
His discoveries transformed creatine from gym folklore into one of the most studied and validated supplements in sports science.
Who is Paul Greenhaff?
| Credential | Detail |
|---|---|
| Role | Professor of Muscle Metabolism, University of Nottingham |
| Known For | Creatine transport mechanisms, the "responder vs. non-responder" discovery, carnitine metabolism |
| Collaborations | Gatorade Sports Science Institute, Lonza Ltd, MRC/BBSRC funding |
| Recognition | 30+ years continuous research funding; Senior Editor, Journal of Physiology |
Greenhaff bridges basic biochemistry and commercial sports nutrition. His lab has shaped the formulation of supplements used by athletes worldwide.
What ISP Students Learn
Lesson 1: Creatine Works—But Not By Magic
Creatine is stored in your muscles as phosphocreatine (PCr). During short, intense efforts (sprints, heavy lifts), your body uses PCr to rapidly regenerate ATP—the energy currency of cells.
More creatine stored = faster ATP regeneration = better performance in explosive efforts.
What Greenhaff proved:
- Creatine supplementation increases muscle creatine stores by 20-40%
- This translates to real performance gains in high-intensity, short-duration activities
- The effect is measurable through muscle biopsies, not just gym PRs
What this means for young athletes: Creatine isn't magic—it's chemistry. It helps with power sports, not endurance.
Lesson 2: Insulin Drives Creatine Into Muscles
Greenhaff's breakthrough: creatine doesn't just float into muscle cells. It requires active transport that's enhanced by insulin.
His studies showed that taking creatine with 90-100g of carbohydrates increased muscle creatine uptake by 60% compared to creatine alone.
The carbs spike insulin, which activates the sodium-potassium pump that drives creatine into cells.
Practical refinement: Later research showed that 50g carbs + 50g protein works just as well (the amino acids help trigger insulin). This reduces the sugar load while maintaining effectiveness.
What this means for young athletes: If you use creatine, take it with a meal containing carbs and protein—not just water.
Lesson 3: Some People Are "Non-Responders" (And That's Okay)
Greenhaff's most nuanced contribution: discovering that 20-30% of people don't respond to creatine.
Through muscle biopsies, he found that non-responders typically have:
- High baseline creatine levels already (often meat-eaters)
- Lower percentage of Type II (fast-twitch) muscle fibers
- Muscles that are already near their storage ceiling
If you're already "full," supplementation can't add more.
Conversely, the best responders tend to be:
- Vegetarians/vegans (lower dietary creatine intake)
- People with higher proportions of fast-twitch fibers
- Those with lower baseline stores
What this means for young athletes: If creatine doesn't seem to work for you after 4-6 weeks, you might be a non-responder. That's not failure—it's individual variation.
Lesson 4: Nutrients Don't Work in Isolation
Greenhaff's philosophy: a supplement's effectiveness depends entirely on the hormonal and metabolic environment in which it's taken.
Creatine with carbs works better than creatine alone. Protein timing matters relative to training. The same nutrient can have different effects depending on when and how it's consumed.
"A supplement is not merely a molecule acting in isolation; its efficacy is dictated by the hormonal environment in which it is introduced."
What this means for young athletes: Context matters. When you eat something matters almost as much as what you eat.
Key Takeaways
| Lesson | One-Liner |
|---|---|
| Creatine is proven | It increases muscle stores and improves short, intense performance |
| Take it with food | Carbs + protein enhance uptake by 60% |
| Non-responders exist | 20-30% of people won't benefit—individual variation is real |
| Context matters | The same nutrient works differently in different conditions |
How This Shows Up at ISP
Paul Greenhaff's research shapes supplement education in the Bio Skill Tree:
- Creatine is taught as one of the few proven supplements (alongside caffeine and nitrate)
- We teach the "take with food" protocol, not dry scooping
- Individual variation is emphasized—not everyone responds the same
- The "responder/non-responder" concept teaches that personalization matters
When ISP students learn about supplements, they learn what actually works—and why—not marketing claims.
Beyond Creatine: The Carnitine Breakthrough
Greenhaff's later work showed that carnitine supplementation can work—but only with a specific protocol:
- 1.36g L-carnitine + 80g carbs, twice daily, for 24 weeks
- Result: 21% increase in muscle carnitine
- Effect: 55% less glycogen used during low-intensity exercise; reduced lactate at high intensity
This challenged the dogma that oral carnitine doesn't increase muscle levels. It does—but it requires a long, consistent protocol with carbs.
Learn More
"Biological variability is a primary determinant of nutritional efficacy."