Carbohydrate Availability Crucial for Runners Under Energy Deficit — image accompanying Marathon Handbook's report. Image accompanying Marathon Handbook’s report; reduced and presented for news commentary with the attributed report. View the complete source report.
Runners often focus on calorie balance, but carbohydrate availability is crucial. Marathon Handbook reports that low energy availability can lead to physiological changes. Runners may consume enough calories but lack sufficient carbohydrates for their training demands.
A study found that higher carbohydrate availability can mitigate some hormonal declines. Participants experienced less suppression of IGF-1 with more carbohydrate. However, body mass and IGF-1 still declined, and fuel use shifted towards fat. Read more everyday miles coverage.
The study highlights the importance of carbohydrate for high-intensity exercise and hormone regulation. Runners should consider carbohydrate needs relative to their training. Protecting carbohydrate may help during short-term energy mismatches, but restoring energy availability remains essential. Related: New Challenge to Help Runners Achieve 2025 Goals.
This original Runner World brief is based on reporting from Marathon Handbook. Visit the source for its complete reporting, context and any later corrections.
Reader questions
Questions about this report
What should runners know about Carbohydrate Availability Crucial for Runners Under Energy Deficit?
Low energy availability affects runners, but carbohydrate intake plays a key role. Runners often focus on calorie balance, but carbohydrate availability is crucial. Marathon Handbook reports that low energy availability can lead to physiological changes. Runners may consume enough calories but lack sufficient carbohydrates for their training demands.
When did Runner World publish this everyday miles brief?
Runner World published this brief on July 30, 2026. The underlying Marathon Handbook report was dated July 30, 2026.
Where can readers find the complete original report?
This summary is based on reporting from Marathon Handbook. The attributed source link in the article leads to the publisher’s complete report.
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