Glucose uptake after resistance training of different intensities but of equal work volume.

High-intensity (HI) resistance exercise augments postexercise glucose uptake to a greater degree than low-intensity (LO) resistance exercise; however, few studies have equated the work volumes between intensity levels. The purpose of this study was to compare the effect of acute HI and LO resistance exercise of equal work volume on glucose uptake in resistant-trained men. Fifteen healthy male (22.9 +/- 3.8 years old), resistance-trained (6.7 +/- 3.9 years) subjects completed three treatment sessions: CON (no-exercise control), HI (3 x 8, 85% 10-RM), and LO (3 x 15, 45% 10-RM). HI and LO sessions consisted of eight exercises. Glucose uptake was measured the following morning by using the hyperinsulinemic euglycemic clamp technique. Glucose disposal was measured by analyzing the glucose infusion rate during the final 30 minutes of steady-state blood glucose concentrations. Insulin sensitivity was calculated by dividing the glucose infusion rate by the average insulin infusion. Results indicate that fasting blood glucose levels were not significantly different among treatment sessions (CON = 80.5 +/- 5.3 versus HI = 77.0 +/- 4.9 versus LO = 77.1 +/- 6.0 mg.dL). Glucose uptake was not significantly different among treatment sessions (CON = 11.3 +/- 3.0 versus HI = 11.7 +/- 2.7 versus LO = 11.4 +/- 2.8 mg.kg FFM.min). Insulin sensitivity did not change among treatment sessions (CON = 0.26 +/- 0.09 versus HI = 0.28 +/- 0.07 versus LO = 0.27 +/- 0.06 (mg.kg FFM.min)/(uU.mL)). The data indicate that the resistance training sessions did not modify acute insulin sensitivity. This may have been because of the high levels of fitness of the subjects, which allowed for the cellular adaptations for enhanced insulin sensitivity and glucose uptake that are unaffected by this volume of acute exercise.

Aerobic exercise alters postprandial lipemia in African American versus White women.

PURPOSE: To determine whether ethnicity influences postprandial lipemia after a bout of aerobic exercise. METHODS: Randomized crossover design. Healthy White (W; n=6) and African American (AA; n=6) women (age, W 27.0+/-3.3 yr, AA 21.6+/-1.4 yr; body-mass index, W 25.0+/-0.93 kg/m2, AA 25.8+/-0.79 kg/m2) participated in 2 treatments (control and exercise), each conducted over 2 d. On d 1, participants rested (control) or walked at 60% of maximal oxygen uptake for 90 min (exercise) and then consumed a meal. On d 2, after a 12-hr overnight fast, participants consumed an oral fat-tolerance test (OFTT) meal of 1.7 g fat, 1.65 g carbohydrate, and 0.25 g protein per kg fat-free mass. Blood was collected pre-meal and at 0.5, 1, 2, 3, 4, 5, and 6 hr post-OFTT and analyzed for triacylglycerol (TAG), glucose, and insulin. Areas under the curve (AUCs) were calculated for each blood variable. RESULTS: A significantly lower TAG AUC was observed for AA (0.86+/-0.24 mmol x L(-1) x 6 hr(-1)) after exercise than for W (2.25+/- .50 mmol x L(-1) x 6 hr(-1)). Insulin AUC was significantly higher for AA after exercise (366.2+/-19.9 mmol x L(-1) x 6 hr(-1)) than for the control (248.1+/-29.2 mmol x L(-1) x 6 hr(-1)). CONCLUSIONS: The data indicate that exercise performed approximately 13 hr before an OFTT significantly reduces postprandial lipemia in AA compared with W. It appears that AA women have an increased ability to dispose of TAG after exercise and a high-fat meal.

Physical activity and quality of life improvements before obesity surgery.

OBJECTIVE: To examine quality of life (QOL), physical activity (PA), and physical activity readiness (PAR) among gastric-bypass surgery (GBS) candidates. METHODS: The SF-36v2, International Physical Activity Questionnaire, and a stages-of-change measure assessed QOL, PA, and PAR respectively across 2 presurgical visits. RESULTS: Increases in mental QOL, PA, and PAR were observed across visits. Sufficiently physically active participants reported significantly higher physical QOL than did insufficiently physically active participants. CONCLUSIONS: Findings demonstrating positive presurgical changes in PA and PA readiness as well as the association between PA and QOL warrant increased efforts to promote PA adoption and maintenance among GBS candidates.

Resistance exercise and postprandial lipemia: The dose effect of differing volumes of acute resistance exercise bouts.

INTRODUCTION: Resistance exercise has been shown to reduce postprandial lipemia, but no dose-response effect has been established. PURPOSE: The purpose of this study was to determine whether prior resistance exercise exhibited a dose-response effect on postprandial lipemia, while controlling for energy balance. METHODS: Subjects were healthy resistance-trained men (n = 4) and women (n = 6) aged 23.4 +/- 2.5 years. Subjects participated in 4 different treatment conditions consisting of control (no exercise), 1 set, 3 sets, and 5 sets of 8 resistance exercises in a repeated-measures design. On day 1, each exercise was performed at 75% of the subject's 1-repetition maximum for 10 repetitions. This was followed by consumption of a postexercise meal equal in caloric volume designed to maintain energy balance. On day 2, after a 12-hour overnight fast (approximately 13 hours postexercise) in the General Clinical Research Center, subjects consumed a high-fat meal consisting of 1.7 g fat, 1.65 g carbohydrate, 0.25 g-protein per kilogram of fat-free mass and equal to 95 kJ of energy per kilogram of fat-free mass. Blood collections occurred before meal, and at 0.5, 1, 2, 3, 4, 5, and 6 hours after meal consumption and were analyzed for triacylglycerol (TAG), glucose, and insulin concentrations. The lipemic response was evaluated as the area under curve (AUC) for TAG versus time. Glucose and insulin AUCs were also calculated. RESULTS: No significant differences were observed among treatments for postprandial lipemia (mmol/L per 6 hours) as measured by the TAG AUC (control 2.96 +/- 0.79, 1 set 2.52 +/- 0.60, 3 sets 2.61 +/- 0.59, 5 sets 2.45 +/- 0.58). Similarly, no differences were observed for insulin or glucose AUC or for insulin sensitivity between treatments. There was a sex effect with TAG AUC significantly lower in women for control, 1 set, and 3 sets. Conclusion The results of this investigation suggest no dose-response attenuation of the postprandial lipemic response to a high-fat meal after previous resistance exercise.

A conceptual application of health behavior theory in the design and implementation of a successful surgical weight loss program.

Obesity (BMI > or =30 kg/m(2)) is recognized as a primary risk factor in the pathogenesis of several leading causes of morbidity and mortality, most notably hypertension, diabetes, and coronary artery disease. Despite numerous preventive approaches, the number of Americans who are overweight and obese has reached pandemic proportions and continues to increase. Moreover, the "fat are becoming fatter" as evidenced by the increasing prevalence of morbidly obese individuals (BMI > or =40 kg/m(2)). For the morbidly obese individual with potentially life-threatening comorbidities, the support for and use of surgical treatment options as a corrective mechanism is growing. Weight reduction results for bariatric surgery average 30-80% of excess body weight, depending on the length of the follow-up and the surgical technique. The demonstrated effectiveness of surgical treatment as a weight-reduction method coupled with the increasing prevalence of severe obesity is certain to increase the popularity of surgical treatment options. With this increased popularity, comes a responsibility for health-care professionals to guard against patients' perception of surgical treatment as a panacea. To counter this possibility, three recommendations are presented as components of a treatment paradigm by a multidisciplinary team of health professionals, which incorporate surgical and non-surgical treatment components, increase patient responsibility, promote lifelong health behavior change and effect permanent weight loss.