People following a low or high glycaemic index (GI) diet are more likely to have better endurance performance compared to those on a low carb diet, academics have said.

A new study has found that individuals on a carbohydrate-rich low-GI diet (LOW-GI) had higher values in the graded exercise test, a reduced energy intake, good maintenance of glycogen stores, an improved five-kilometre time trial (TT) performance and decreased blood lactate concentrations during exercise.

People on a low carbohydrates and high fat (LCHF) diet did improve fat oxidation in the incremental test, but the meal plan did impact their training adaptions at higher intensities, carbohydrate oxidation and muscle glycogen restoration, the research has reported.

In addition, the findings have shown that those on a carbohydrate-rich high-GI diet (HIGH-GI) had better intensities and more muscle glycogen content, but their fat oxidation reduced after 10 weeks.

According to the study, the LCHF diet can trigger health complications, despite its benefits for body composition and fat oxidation.

People on a LOW-GI diet are more likely to have an improved metabolic flexibility because of their facilitation of fat utilisation and their reduced plasma lactate concentrations.

Experts say that carbohydrates are vital for people who want to complete long sessions of endurance exercise.

Full glycogen stores and optimal metabolic flexibility are crucial for maintaining high endurance performance.

Read the full study in the journal Sports Medicine.

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