Each week in my Research Update, I distill the latest sports science research into practical insights to help you improve your training, performance, and recovery.
In this week's update:
- Challenging existing carbohydrate intake guidelines
- A framework for fuelling before, during, and after training
-
How a low-carb diet can actually limit athletic performance
Carbohydrate Intake Guidelines for Athletes Are Evolving
This review revisited carbohydrate intake recommendations for endurance athletes, highlighting how the body can adapt to higher carb intakes than previously thought. It showed that absorption rates vary widely, that the traditional 2:1 glucose-to-fructose ratio may not be optimal (with some newer evidence supporting closer to 1:1), and that higher intakes (e.g., 90 g/hour) don’t guarantee full absorption. It also highlights that carbohydrate tolerance is trainable, meaning athletes can improve their ability to handle higher intakes over time. As a result, the authors suggest moving away from fixed intake targets toward more individualized strategies based on exercise demands.
My thoughts: This is a great update that challenges the existing carb absorption rules and shows how adaptable the body really is.
Some useful takeaways:
- Cyclists tend to tolerate higher intakes better
- 2:1 glucose-to-fructose may not be optimal anymore
- Just because you ingest 90g doesn’t mean you absorb it all
My suggestion is to try out several different levels of carb intake in training, and remember, you can train your gut to handle more over time.
The “4P’s” Framework for Fuelling Before, During, and After Training
This review introduced the “4Ps” framework—preparation, pre-exercise, performance, and post-exercise—to guide nutrition strategies across the full training and competition window. Preparation focuses on daily nutrition and glycogen availability, pre-exercise on topping up carbohydrates and fluids in the hours before, performance on fueling (carbs, fluids, electrolytes) during exercise, and post-exercise on rapid carbohydrate and protein intake to support recovery and adaptation. The framework emphasizes adjusting these based on the athlete, session demands, and environment.
My thoughts: This is a solid review with practical fuelling guidance based on current research.
A few things to keep in mind:
- Be careful with pre-hydration and don’t overdo it or go too close to competition (leave time for your fluid levels to normalize)
- Beet juice works best when nitrate content is known and consistent (like the 400mg dose in Beet It Sport Nitrate 400)
- Don’t overdo the caffeine, as it can tip the scale from helpful to disruptive quickly
Burning More Fat (and Less Carbs) Doesn’t Always Lead to Better Performance
This systematic review and meta-analysis examined low-carbohydrate and ketogenic diets in trained athletes and found that while these diets increase fat oxidation, they do not improve (and often impair) aerobic performance compared to higher-carbohydrate diets. Despite metabolic adaptations, the reduced ability to use carbohydrates during exercise appears to limit performance at higher intensities.
My thoughts: This confirms what most sports scientists already know. Keto diets shift the body toward burning fat, but working muscles still prefer carbs when intensity rises. If performance is the goal, a ketogenic bias doesn’t help you much.
That’s all for this week.
If you learned something new and are curious to know more, check out more articles and my growing list of weekly Blonyx Research Updates where I help you further improve your athletic performance by keeping you up to date on the latest findings from the world of sports science.
— That's all for now, train hard!
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