Effect of food intake on exercise fatigue in trained and untrained subjects

The effects of carbohydrate and fat intake on exercise-induced fatigue was investigated in 30 untrained - ( {Mathematical expression} of 40.6±2.7 ml · kg^-1 · min^-1) and 24 trained-subjects ( {Mathematical expression} of 52.3±2.7 ml · kg^-1 · min^-1) performing a 34 km march with a 25 kg backpack. Marching time was 8 1/2 h and 6 1/3 h in the untrained and trained-subjects respectively. The subjects were divided into 3 dietary groups. One group had free access to sugar cubes, the second group was offered almonds and the third one served as a control. Triglyceride levels decreased by 65 mg · dl^-1 in untrained, and by 115 mg · dl^-1 in trained subjects, while blood glucose remained at normal levels. In the untrained subjects, ingestion of almonds delayed the subjective sensation of exhaustion, while 50% of the controls and the sugar consuming subjects complained of exhaustion. The data suggest that ingestion of food containing fat delays exercise induced exhaustion or fatigue to a greater extent than does carbohydrate ingestion.