Carbohydrate availability, not generic carb restriction, is what periodized 'train low' protocols are actually targeting — and what preserves late-race power
Interpretation
Impey et al.'s glycogen threshold hypothesis frames 'train low, compete high' benefits as most apparent when sessions are deliberately commenced within a specific muscle-glycogen range — a targeted, measured approach, not simply restricting carbohydrate intake broadly. This matters for both how coaches should design train-low blocks and how to think about late-race power fade as a fuelling-availability problem.
Practical implication
Any 'train low' guidance should specify the glycogen-threshold targeting logic (which sessions, and why), not present carbohydrate restriction as a blanket strategy applicable to any session.
Sources
1 source, independently verified.
Sports Medicine 48(5):1031-1048. Proposes the 'glycogen threshold hypothesis': 'train low, compete high' benefits (augmented cell signalling, gene expression, oxidative enzyme adaptation) are especially apparent when training sessions are deliberately commenced within a specific muscle-glycogen range, not simply from restricting carbohydrate generally.