Carbohydrate and training: Evidence-Based Supplement Guide

Carbohydrate is stored in muscle as glycogen, and enough of it lets you complete demanding training (PMID 29453741). Training low means deliberately training with less carbohydrate available, to boost the muscle's adaptations to endurance training (PMID 29453741). Training low raised markers of muscle adaptation in most studies, but performance did not always follow. Of 11 studies, 37 percent showed better performance and 63 percent showed no change (PMID 29453741). The fuel for the work required approach adjusts carbohydrate to the demands of the coming session (PMID 29453741). Its authors stress that training intensity should not be compromised (PMID 29453741). A joint position statement from three nutrition and sports medicine bodies states that well-chosen nutrition strategies enhance sporting performance (PMID 26891166). It advises referral to a registered dietitian for a personal plan (PMID 26891166).

1. **Match carbohydrate to the session ahead**, with more for demanding sessions and less for easy ones (PMID 29453741). 2. **Fuel your hardest sessions so the work gets done.** The approach aims to keep training intensity intact (PMID 29453741). 3. **Keep training low for specialist use.** It did not reliably improve performance in the studies reviewed (PMID 29453741). 4. **For a personal plan, see a registered dietitian**, as the joint position statement advises (PMID 26891166).

In training low studies, reduced carbohydrate was used for some sessions, often 30 to 50 percent of them, rather than all the time (PMID 29453741). The position statement covers nutrition across training and competition (PMID 26891166).

- **The fuel for the work required approach is a theoretical framework**, and the glycogen threshold it proposes is a hypothesis (PMID 29453741). - **Better muscle markers did not reliably mean better performance** in the training low studies (PMID 29453741). - **The position statement is a consensus document**, which weighs research and expert judgement rather than reporting one new trial (PMID 26891166). - **No dose appears in this guide.** Carbohydrate amounts depend on the person and the training, and are held for review with a registered dietitian or clinician. - **This guide has not been reviewed by a clinician.** `reviewStatus` above says so.

- **If you have a long-term health condition or take regular medicines, plan changes to how you eat around training with a clinician or registered dietitian.** - **Do not cut carbohydrate before hard sessions you need to complete.** The approach aims to keep training intensity intact (PMID 29453741).

No ingredient is linked from this guide. It covers how carbohydrate fuels training, and it does not point to a product.

| PMID | Title | | --- | --- | | 29453741 | "Fuel for the Work Required: A Theoretical Framework for Carbohydrate Periodization and the Glycogen Threshold Hypothesis" | | 26891166 | "American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance" |