UNLABELLED The glycemic index (GI) of a preexercise meal may affect substrate utilization and performance during continuous exercise. PURPOSE To examine the effects of low- and high-GI foods on metabolism and performance during high-intensity, intermittent exercise. METHODS Seven male athletes participated in three experimental trials (low-GI, high-GI, and fasted control) separated by appro...

Pre-exercise meals containing carbohydrates (CHO) are recommended to athletes, although there is evidence to suggest that a high fat meal prior to exercise increases utilisation of fats yet may not adversely affect performance. This study investigated the effect of a high fat and high CHO pre-exercise meal prior to high intensity intermittent exercise. Ten male recreational soccer players perfo...

background: fatty acids are an important source of energy for muscle contraction, particularly during longtime exercise. the objective of this clinical trail study was to determination effect of heparin infusion on lipids metabolism during submaximal exercise. methods: forty boy students performed astrand ergometery protocol for 20-minute on cycle ergometer in two separate occasions. stage1 wit...

Endurance exercise increases the use of endogenous fuels to provide energy for working muscles. Elderly subjects oxidize more glucose and less fat during moderate intensity exercise. This shift in substrate use is presumably caused by age-related changes in skeletal muscle, including decreased skeletal muscle respiratory capacity, because adipose tissue lipolysis and plasma fatty acid availabil...

Our group (Magkos F, Wright DC, Patterson BW, Mohammed BS, Mittendorfer B, Am J Physiol Endocrinol Metab 290: E355-E362, 2006) has recently demonstrated that a single, prolonged bout of moderate-intensity cycling (2 h at 60% of peak oxygen consumption) in the evening increases basal whole-body free fatty acid (FFA) flux and fat oxidation, decreases hepatic VLDL-apolipoprotein B-100 (apoB-100) s...

We examined the relationship between energy expenditure (in kcal) and epinephrine (Epi), norepinephrine (NE), and growth hormone (GH) release. Ten men [age, 26 yr; height, 178 cm; weight, 81 kg; O(2) uptake at lactate threshold (LT), 36.3 ml. kg(-1). min(-1); peak O(2) uptake, 49.5 ml. kg(-1). min(-1)] were tested on six randomly ordered occasions [control, 5 exercise: at 25 and 75% of the diff...

Not only increasing body carbohydrate (CHO) stores before exercise but also suppressing CHO oxidation during exercise is important for improving endurance performance. We tested the hypothesis that intensive high-fat ingestion in the early stage of recovery from exercise training (ET) for 2 d would suppress CHO oxidation during exercise by increasing whole body lipolysis and/or fat oxidation. I...

This study determined if the suppression of lipolysis after preexercise carbohydrate ingestion reduces fat oxidation during exercise. Six healthy, active men cycled 60 min at 44 ± 2% peak oxygen consumption, exactly 1 h after ingesting 0.8 g/kg of glucose (Glc) or fructose (Fru) or after an overnight fast (Fast). The mean plasma insulin concentration during the 50 min before exercise was differ...