Appetite, gut hormone and energy intake responses to low volume sprint interval and traditional endurance exercise.

Sprint interval exercise improves several health markers but the appetite and energy balance response is unknown. This study compared the effects of sprint interval and endurance exercise on appetite, energy intake and gut hormone responses. Twelve healthy males [mean (SD): age 23 (3) years, body mass index 24.2 (2.9) kg m(-2), maximum oxygen uptake 46.3 (10.2) mL kg(-1) min(-1)] completed three 8 h trials [control (CON), endurance exercise (END), sprint interval exercise (SIE)] separated by 1 week. Trials commenced upon completion of a standardised breakfast. Sixty minutes of cycling at 68.1 (4.3) % of maximum oxygen uptake was performed from 1.75-2.75 h in END. Six 30-s Wingate tests were performed from 2.25-2.75 h in SIE. Appetite ratings, acylated ghrelin and peptide YY (PYY) concentrations were measured throughout each trial. Food intake was monitored from buffet meals at 3.5 and 7 h and an overnight food bag. Appetite (P 0.05). Therefore, relative energy intake (energy intake minus the net energy expenditure of exercise) was lower in END than that in CON (15.7 %; P = 0.006) and SIE (11.5 %; P = 0.082). An acute bout of endurance exercise resulted in lower appetite perceptions in the hours after exercise than sprint interval exercise and induced a greater 24 h energy deficit due to higher energy expenditure during exercise

Comparing Distance-Based Vs. Time-Based Exercise Prescriptions Of Walking And Running For Improvement Of Cardiovascular Disease Risk Factors

The many benefits of participation in a regular physical activity program are well-documented (Haskell et al., 2007; Pate et al., 1995). Brisk walking and jogging are commodes of exercise that is easily measured and evaluated by a self-report method that is comin both clinical and research settings. Some research has suggested that walking for distance as opposed to walking for time may be a stronger predictor of overall amount of accumulated exercise or physical activity (Williams, 2012a). To our knowledge, research has not been conducted directly comparing a distance-based versus time-based brisk walking prescription for the improvement of cardiovascular risk factors. The primary purpose of this study was to compare walking/running for distance to walking/running for time as part of a weight loss intervention to assess similarities or differences. Another purpose was to evaluate included the feasibility of a previously published regression equation in predicting energy expenditure for walking or running for a one-mile distance before and after exercise weight loss intervention. This study folloa between-subjects, repeated measures design with each participant reporting for pre-intervention as well as post-intervention testing. Twenty-one overweight, but otherwise healthy participants [10 for distance-based (dist) group, 11 for time-based (time) group] were recruited but only 15 participants completed the study (9 time, 6 dist). Informed consent was obtained from the participants who fit the inclusion criteria based on the physical activity readiness questionnaire and body composition measurements using dxa. Participants were required to complete four testing sessions at the beginning of intervention and three testing sessions at the completion of intervention. Each testing session was separated by 24 hours. The time intervention group walked and ran for self-reported exercise time completed per day, and accumulated per week. The dist intervention group walked and ran for self-reported exercise distance completed per day, and accumulated per week. Each participant was measured for the following postabsorptive variables: lipid panel which included (total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglycerides), glucose, resting metabolic rate (rmr). Body composition, vo2 max, measured kcal/mile and predicted kcal/mile were also measured before and following intervention. A mixed-factor repeated- measures anova (rm-anova) was used to compare all cardiovascular disease risk-related dependent variables before and after intervention (body weight, body composition, blood lipids & glucose, rmr, vo2 max) for within-subjects and between-subjects comparisons. A mixed-factor repeated-measures anova was also used to compare weekly adherence rates to the exercise program. If interactions occurred, they were folloup with a sidak adjustment for multiple pairwise comparisons. Overall, the groups adhered to the exercise programs at similar rates. Significant interactions were shown for mean body weight loss between groups as well as mean blood glucose level (p \u3c 0.05). The dist group lost an average of 4.0 kg while the time group gained an average of 1.1 kg. The dist group exhibited a decline in their blood glucose level by an average of 10.5 mg/dl while the time group shoan increase in their blood glucose level by an average of 4.7 mg/dl. Additionally, running one-mile was significantly more expensive metabolically than walking the mile at both pre- and post-intervention. Also, excess post-exercise oxygen consumption was significantly greater in the five minutes following running compared to walking. To the best of the author\u27s knowledge, the present study is the first to directly compare a distance-based vs. A time-based exercise program for walking and running for improvement of risk factors of cvd. The results of the particular study would suggest that a distance-based exercise prescription of walking or running should provide a clinician or researcher with a closer estimation of overall ee and resultantly weight loss and reduction of particular risk factors for cvd

A Comparison Of Energy Expenditure And Prediction Equations During Walking Or Running Corrected For One Mile In Normal Weight And Overweight African American, Asian, And Caucasian Adults And Cross-Validation Of The Equations

The prevalence of obesity is rapid across the world. Knowledge of the actual energy expenditure (EE) of walking and running can lead to a more precise exercise prescription which may lead to an obesity reduction or avoidance. Limited research has focused on EE during walking and running. Therefore, the aims of this study included developing ethnic based cross validated EE prediction equations for African American, Asian and Caucasian adults, and a multiple regression equation developed that included all three ethnic groups. Also, the energy expenditure among these three ethnic groups was compared. A total of 224 subjects, including 71 Caucasians, 68 African Americans and 85 Asians were recruited to test EE through indirect calorimetry. Analysis of variance (ANOVA) was used for over- all significance with post Hoc Scheffe test to compare EE in three groups (normal weight walkers, overweight walkers and runners). Multiple regression analysis was employed for EE prediction, and a dependent t-test and chow statistical test were used to cross-validate. The results shothat EE in runners was significantly higher than that in normal weight walkers in African Americans. When EE was expressed relative to body weight, similar difference was observed between walkers and runners in both African Americans and Asians. When EE was expressed relative to fat free mass, normal weight walkers expended less energy than runners, both among African Americans and Asians. Furthermore, EE in African Americans was significantly higher than that in Caucasians and in Asians. Three EE prediction equations were developed specifically for African Americans, Asians, and the three ethnic groups. Through cross-validation, all the three equations were valid and they were all recommended to apply for calculating EE during walking or running one mile. The overall prediction equation was: EE=0.978 bw-4.571 gender (m=1, f=2)+3.524 ethnicity (Caucasians=1, AA=2, Asians=3)+32.447 (r=0.77; see=12.5 kcalâ·mile-1)

Energy cost and return for hunting in African wild dogs and Cheetahs

African wild dogs (Lycaon pictus) are reported to hunt with energetically costly long chase distances. We used high-resolution GPS and inertial technology to record 1,119 high-speed chases of all members of a pack of six adult African wild dogs in northern Botswana. Dogs performed multiple short, high-speed, mostly unsuccessful chases to capture prey, while cheetahs (Acinonyx jubatus) undertook even shorter, higher-speed hunts. We used an energy balance model to show that the energy return from group hunting and feeding substantially outweighs the cost of multiple short chases, which indicates that African wild dogs are more energetically robust than previously believed. Comparison with cheetah illustrates the trade-off between sheer athleticism and high individual kill rate characteristic of cheetahs, and the energetic robustness of frequent opportunistic group hunting and feeding by African wild dogs

Doctor of Philosophy

dissertationThe purpose of this study was to determine whether 12 weeks of high dose (26 kcal/kg/week) or low dose (13 kcal/kg/week) endurance exercise is more efficacious for losing body weight, fat mass, and waist circumference and for temporarily elevating resting energy expenditure (REE) after a single bout of exercise in healthy yet sedentary, overweight, premenopausal women. Twenty-four volunteers were randomly assigned to either a high or low dose of exercise and completed 12 weeks of endurance training. Twelve-week changes in body weight, body composition, and waist circumference were not different between high dose and low dose exercise groups. Additionally, there were no group differences for change in postexercise REE (19-hour to 43-hour REE) after a single bout of prescribed exercise (5.2 kcal/kg versus 2.6 kcal/kg). However, there was substantial individual variability in the change in body weight (-3.9 to +3.2 kg), fat mass (-4.1 to +4.2 kg), waist circumference (-5.0 to + 3.3 cm), and postexercise REE (-341.0 to +645.4 kcal/day) in response to exercise training. Correlational analyses determined that average exercise energy expenditure accounted for 25% and 31% of the variability in the change in fat mass and waist circumference, respectively. Average exercise energy expenditure also accounted for 24% of the variability in 19-hour postexercise REE. Nineteen-hour postexercise REE was found to account for 25% and 35% of the variability in the iv change in fat mass and waist circumference, respectively. Nineteen-hour postexercise REE also accounted for 26% of the variability in the change in fat-free mass. In post hoc analyses, subjects were classified as exercise dose achievers or nonachievers. By definition, achievers were those participants who were able to sustain 13 kcal/kg/week for the final 5 weeks of training. When compared to nonachievers, achievers had greater reductions in fat mass (p= 0.03), waist circumference (p< 0.01), and body mass index (p=0.03). Moreover, achievers had an 18.1% higher 19-hour postexercise REE (p=0.03) as compared to nonachievers. These results suggest that the success of a given exercise prescription to elicit body weight and body composition improvements may depend on its ability to elicit increases in postexercise metabolic rate

Appetite, energy intake and resting metabolic responses to 60 min treadmill running performed in a fasted versus a postprandial state.

This study investigated the effect of fasted and postprandial exercise on appetite, energy intake and resting metabolic responses. Twelve healthy males (mean±SD: age 23±3 years, body mass index 22.9±2.1 kg m(-2), maximum oxygen uptake 57.5±9.7 mL kg(-1) min(-1)) performed three 10 h experimental trials (control, fasted exercise and postprandial exercise) in a Latin Square design. Trials commenced at 8 am after an overnight fast. Sixty min of treadmill running at ∼70% of maximum oxygen uptake was performed at 0-1 h in the fasted exercise trial and 4-5 h in the postprandial exercise trial. A standardised breakfast was provided at 1.5 h and ad libitum buffet meals at 5.5 and 9.5 h. Appetite ratings and resting expired air samples were collected throughout each trial. Postprandial exercise suppressed appetite to a greater extent than fasted exercise. Ad libitum energy intake was not different between trials, resulting in a negative energy balance in exercise trials relative to control after accounting for differences in energy expenditure (control: 9774±2694 kJ; fasted exercise: 6481±2318 kJ; postprandial exercise: 6017±3050 kJ). These findings suggest that 60 min treadmill running induces a negative daily energy balance relative to a sedentary day but is no more effective when performed before or after breakfast