How Training and Diet Together Affect Metabolism and Endurance During Exercise in Humans

Maximal oxygen uptake increased by 11% in both carbohydrate-rich and fat-rich diet groups after 7 and 8 weeks of endurance training.

• Time to exhaustion improved significantly in the carbohydrate-rich diet group, increasing from a mean of 35 minutes to 102 minutes after 7 weeks.
• The fat-rich diet group also showed increased endurance time, reaching 77 minutes after 8 weeks, but this was still less than the carbohydrate-rich group.
• Muscle glycogen breakdown rate during exercise was reduced by half in both diet groups after 7 and 8 weeks of training.
• Respiratory exchange ratio decreased in the fat-rich group after 7 weeks, but stabilized around 0.87 for both groups after 8 weeks.
• Plasma noradrenaline concentration and heart rate were higher in the fat-rich diet group compared to the carbohydrate-rich group at both 7 and 8 weeks.
• Ingesting a fat-rich diet during endurance training may hinder endurance improvements due to suboptimal adaptations.

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