BACKGROUND Adjustments of carbohydrate intake and oxidation occur in both normal-weight and overweight individuals. Nevertheless, the contribution of carbohydrates to the accumulation of fat through either reduction of fat oxidation or stimulation of fat synthesis in obesity remains poorly investigated. OBJECTIVE The objective of this study was to assess the postprandial metabolic changes and...

the aim of the present study was to examine the effect of menstrual cycle on substrate metabolism, energy expenditure and performance during exhaustive incremental exercise in female students. for this purpose, 15 female students (mean age 21.17 ± 1.47 years, bmi 20.55 ± 1.71 kg/m2) participated voluntarily in this study. the design was adjusted in three stages: bleeding, follicular and the lat...

The aim of this study was to determine the relative exercise intensity that elicits maximal fat oxidation during walking in inactive and overweight men and women and evaluate any possible sex differences. Forty six healthy, sedentary, overweight men (age: 36.3 ± 1.3 years, body fat: 28.8 ± 0.8%, n = 28, mean ± SE) and women (age: 36.6 ± 1.8 years, body fat: 37.1 ± 0.8%, n = 18) participated in ...

The aim of this study was to determine the effects of exercise at different intensities on 24-h energy expenditure (EE) and substrate oxidation. Sixteen adults (8 men and 8 women) were studied on three occasions [sedentary day (Con), a low-intensity exercise day (LI; 400 kcal at 40% of maximal oxygen consumption) and a high-intensity exercise day (HI; 400 kcal at 70% of maximal oxygen consumpti...

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...

Skeletal muscle insulin resistance entails dysregulation of both glucose and fatty acid metabolism. This study examined whether a combined intervention of physical activity and weight loss influences fasting rates of fat oxidation and insulin-stimulated glucose disposal. Obese (BMI >30 kg/m(2)) volunteers (9 men and 16 women) without diabetes, aged 39 +/- 4 years, completed 16 weeks of moderate...

Fat oxidation during exercise is increased by endurance training, and evidence suggests that fat oxidation during exercise is impaired in obesity. Thus the primary aim of this study was to compare the acute effects of exercise on 24-h fat oxidation and fat balance in lean sedentary [LS, n = 10, body mass index (BMI) = 22.5 +/- 6.5 kg/m(2)], lean endurance-trained (LT, n = 10, BMI = 21.2 +/- 1.2...

OBJECTIVE The aim of the present study is to examine the differences in fat and carbohydrate (CHO) oxidation during walking and running between normal-weight and overweight/obese young adult men. METHODS 19 healthy, normal-weight (age = 21.9 ± 0.7 years, BMI = 22.6 ± 0.4 kg, n = 10) and overweight (age = 21.4 ± 0.6 years, BMI = 31.6 ± 1.1, n = 9) young men volunteered to participate in this s...

Short-term alterations in dietary carbohydrate (CHO) energy are known to alter whole-body fuel selection in humans, but the metabolic mechanisms remain unknown. We used stable isotope-mass spectrometric methods with indirect calorimetry in normal subjects to quantify the metabolic response to six dietary phases (5 d each), ranging from 50% surplus CHO (+50% CHO) to 50% deficient CHO (-50% CHO),...

BACKGROUND As part of the growing lifestyle diversity in modern society, there is wide variation in the time of day individuals choose to exercise. Recent surveys in the US and Japan have reported that on weekdays, more people exercise in the evening, with fewer individuals exercising in the morning or afternoon. Exercise performed in the post-prandial state has little effect on accumulated fat...