How Do We Really Fuel Athletic Performance?
In this episode of the Dr. Shawn Baker Podcast, Professor Tim Noakes, a world-renowned sports scientist and medical doctor, joins Dr. Baker to dismantle long-standing dogmas regarding carbohydrates, muscle glycogen, and athletic performance.
The Glycogen Myth [00:03:06]
Professor Noakes argues that the traditional "carbohydrate loading" story, which has dominated sports science for over 50 years, is "utterly wrong." His recent research suggests that muscle glycogen is largely irrelevant to exercise performance.
The Two Pools of Carbohydrate [00:04:25]
Noakes identifies two distinct pools of carbohydrates in the body:
- Muscle Glycogen: Historically viewed as "jet fuel," Noakes argues this pool is actually a storage adaptation to handle glucose overloads (excess of 250g/day) and does not limit performance [00:08:12].
- Liver/Blood Glucose: This pool is critical. Fatigue occurs when blood glucose falls, triggering the brain to slow the body down to protect itself [00:06:00].
Performance and Hypoglycemia [00:14:01]
Noakes points out that many studies "proving" carbohydrate benefits are flawed because they are designed to make the control group hypoglycemic.
- If blood glucose is maintained (even at lower levels in keto-adapted athletes), exogenous carbohydrates offer little to no performance benefit for activities under two hours [00:14:31].
- For ultra-endurance events (over two hours), Noakes suggests a "minimum effective dose" of only 10 grams of carbs per hour to prevent hypoglycemia [01:01:06].
Benefits of Low-Carb/Carnivore for Athletes [00:33:52]
Dr. Baker and Prof. Noakes discuss why high-performance athletes are increasingly turning to meat-based diets:
- Reduced Inflammation: High-carb diets can drive visceral fat and systemic inflammation, leading to joint pain and slower recovery [00:35:22].
- Weight Management: Reducing carbs helps eliminate "hidden" visceral fat, which can make athletes leaner and more powerful without losing muscle mass [00:54:34].
- Injury Prevention: Young contact-sport athletes on carnivore diets report fewer soft tissue injuries and faster recovery times [00:34:00].
Hydration and Sodium [00:29:51]
Noakes touches on his work from Waterlogged, debunking the need for aggressive electrolyte and water consumption.
- It is nearly impossible to "lose" enough sodium through sweat to cause hyponatremia; rather, hyponatremia is almost always caused by over-drinking fluid [00:31:51].
- He advocates for "drinking to thirst" rather than following rigid hydration schedules [00:28:54].
Summary Table: Key Takeaways
| Concept | Traditional View | Prof. Noakes' View |
|---|---|---|
| Muscle Glycogen | Essential fuel for high intensity | An "escape route" for excess glucose |
| Carb Loading | Necessary for peak performance | Zero benefit in controlled studies [00:05:39] |
| Fatigue | Caused by "running out of fuel" | A brain-derived sensation to prevent hypoglycemia |
| Keto Adaptation | Impairs high-intensity output | Takes ~4 weeks; performance eventually matches high-carb |
Watch the full interview on YouTube: How Do We Really Fuel Athletic Performance?