Effects and reproducibility of aerobic and resistance exercise on appetite and energy intake in young, physically active adults.
ABSTRACT: Appetite and meal energy intake (MEI) following aerobic (AEx) and resistance (REx) exercises were evaluated in 19 young, active adults. The participants completed duplicate 35-min sessions of AEx, REx, and sedentary control, and consumed an ad libitum pasta meal 30 min postsession. Hunger transiently decreased after AEx but was not influenced by REx. MEI was 14% to 18% higher after AEx and REx than control. These findings are consistent with exercise-stimulated ingestive behavior, not anorexia of exercise.
Project description:<b>Background: </b>HIV-infected adults have increased risk for age-related diseases and low cardiorespiratory fitness that can be prevented and improved with exercise. Yet, exercise strategies have not been well studied in older adults with HIV and may require substantial adaptation to this special population.<br><br><b>Objective: </b>To determine the safety and efficacy of aerobic exercise in older HIV-infected men in a randomized trial comparing different levels of exercise intensity.<br><br><b>Methods: </b>We conducted a pilot exercise trial in 22 HIV-infected men ?50 years of age receiving antiretroviral therapy who were randomized 1:1 to moderate-intensity aerobic exercise (Mod-AEX) or high-intensity aerobic exercise (High-AEX) that was performed three times weekly for 16 weeks in a supervised setting. Primary outcome was cardiorespiratory fitness (VO2peak) measured by treadmill testing. Secondary outcomes were exercise endurance, six-minute walk distance (6-MWD), body composition measured by Dual-energy X-ray absorptiometry (DXA), and fasting plasma levels of lipids and glucose.<br><br><b>Results: </b>VO2peak increased in the High-AEX group (3.6 ±1.2 mL/kg/min, p = 0.02) but not in the Mod-AEX group (0.4 ±1.4 mL/kg/min, p = 0.7) with a significant between group difference (p<0.01). Exercise endurance increased in both the High-AEX group (27 ±11%, p = 0.02) and the Mod-AEX group (11 ±4%, p = 0.04). The 6-MWD increased in both the High-AEX (62 ±18m, p = 0.01) and the Mod-AEX group (54 ±14m, p = 0.01). Changes in VO2peak and 6-MWD were clinically relevant. There were no serious exercise-related adverse events. Dropouts were similar between group (27% overall) and were related to joint pain.<br><br><b>Conclusions: </b>This pilot exercise trial demonstrates that moderate to high-intensity aerobic exercise in older HIV-infected men increases endurance and ambulatory function. However, increased cardiorespiratory fitness was observed only with high-intensity aerobic exercise despite substantial baseline impairment. Future research is needed to determine exercise strategies in older HIV-infected adults that address advanced aging and comorbidity yet are durable and feasible.
Project description:To determine whether aerobic exercise training + weight loss (AEX + WL) would affect the expression of myostatin and its relationship with insulin sensitivity in a longitudinal, clinical intervention study.Thirty-three obese sedentary postmenopausal women and men (n = 17 and 16, age: 61 ± 1 years, body mass index: 31 ± 1 kg/m(2) , VO2 max: 21.9 ± 1.0 mL/kg/min, X ± Standard error of the mean (SEM)) completed 6 months of 3 days/week AEX + WL. During an 80 mU m(-2) min(-1) hyperinsulinemic-euglycemic clamp, we measured glucose utilization (M), myostatin, myogenin, and MyoD gene expression by real-time RT-PCR in vastus lateralis muscle at baseline and 2 h.Body weight (-8%) and fat mass (-17%) decreased after AEX + WL (P < 0.001). Fat-free mass (FFM) and mid-thigh muscle area by computed tomography did not change but muscle attenuation increased (P < 0.05). VO2 max increased 14% (P < 0.001). AEX + WL increased M by 18% (P < 0.01). Myostatin gene expression decreased 19% after AEX + WL (P < 0.05). Basal mRNA myostatin levels were negatively associated with M before the intervention (r = -0.43, P < 0.05). Insulin infusion increased myoD and myogenin expression before and after AEX + WL (both P < 0.001) but basal levels did not change. The insulin effect on myostatin expression was associated with the change in M after AEX + WL (r = 0.56, P < 0.005).Exercise and weight loss results in a downregulation of myostatin mRNA and an improvement in insulin sensitivity in obese older men and women.
Project description:Transcapillary transport of insulin is one determinant of glucose uptake by skeletal muscle; thus, a reduction in capillary density (CD) may worsen insulin sensitivity. Skeletal muscle CD is lower in older adults with impaired glucose tolerance (IGT) compared with those with normal glucose tolerance and may be modifiable through aerobic exercise training and weight loss (AEX+WL). We tested the hypothesis that 6-month AEX+WL would increase CD to improve insulin sensitivity and glucose tolerance in older adults with IGT.Sixteen sedentary, overweight-obese (BMI 27-35 kg/m2), older (63 ± 2 years) men and women with IGT underwent hyperinsulinemic-euglycemic clamps to measure insulin sensitivity, oral glucose tolerance tests, exercise and body composition testing, and vastus lateralis muscle biopsies to determine CD before and after 6-month AEX+WL.Insulin sensitivity (M) and 120-min postprandial glucose (G120) correlated with CD at baseline (r = 0.58 and r = -0.60, respectively, P < 0.05). AEX+WL increased maximal oxygen consumption (VO2max) 18% (P = 0.02) and reduced weight and fat mass 8% (P < 0.02). CD increased 15% (264 ± 11 vs. 304 ± 14 capillaries/mm(2), P = 0.01), M increased 21% (42.4 ± 4.0 vs. 51.4 ± 4.3 µmol/kg FFM/min, P < 0.05), and G120 decreased 16% (9.35 ± 0.5 vs. 7.85 ± 0.5 mmol/L, P = 0.008) after AEX+WL. Regression analyses showed that the AEX+WL-induced increase in CD independently predicted the increase in M (r = 0.74, P < 0.01) as well as the decrease in G120 (r = -0.55, P < 0.05).Six-month AEX+WL increases skeletal muscle CD in older adults with IGT. This represents one mechanism by which AEX+WL improves insulin sensitivity in older adults with IGT.
Project description:The obesity epidemic urges exploration of several parameters that play an important role in our eating behaviours. Post-ingestive sensations can provide a more comprehensive picture of the eating experience than mere satiety measurements. This study aimed to (1) quantify the dynamics of different post-ingestive sensations after food intake and (2) study the effect of protein and carbohydrate on hedonic and post-ingestive responses. Forty-eight participants (mean age 20.4) were served a breakfast meal high in protein (HighPRO) or high in carbohydrate (HighCHO) on two separate days using a randomised controlled crossover design. Post-ingestive sensations were measured every 30 min, for 3 h post intake using visual analogue scale (VAS). Results showed a significant main effect of time for all post-ingestive sensations. HighCHO induced higher hedonic responses compared to HighPRO, as well as higher ratings for post-ingestive sensations such as Satisfaction, Food joy, Overall wellbeing and Fullness. HighPRO, on the other hand, induced higher ratings for Sweet desire post intake. The development of sensations after a meal might be important for consumers' following food choices and for extra calorie intake. More detailed knowledge in this area could elucidate aspects of overeating and obesity.
Project description:The study aimed to assess whether aerobic exercise (AEx) training and a fibre-enriched diet can reduce hepatic fat content (HFC) and increase glycaemic control in pre-diabetic patients with non-alcoholic fatty liver disease (NAFLD). Six-hundred-and-three patients from seven clinics in Yangpu district, Shanghai, China were recruited. Of them 115 individuals aged 50-65-year fulfilled the inclusion criteria (NAFLD with impaired fasting glucose or impaired glucose tolerance) and were randomly assigned into exercise (AEx n?=?29), diet (Diet n?=?28), exercise plus diet (AED n?=?29), or no-intervention (NI n?=?29) groups. Progressive supervised AEx training (60-75% VO2max intensity) was given 2-3 times/week in 30-60?min/sessions, and the diet intervention was provided as lunch with 38% carbohydrate and diet fibre of 12?g/day for 8.6-month. HFC was assessed by 1H MRS. We found that HFC was significantly reduced in the AEx (-24.4%), diet (-23.2%), and AED (-47.9%) groups by contrast to the 20.9% increase in the NI group (p?=?0.001 for all) after intervention. However, only AED group significantly decreased HbA1c (-4.4%, p?=?0.01) compared with the NI group (-0.6%). Aerobic exercise training combined with fibre-enriched diet can reduce HFC more effectively than either exercise or increased fibre-intake alone in pre-diabetic patients with NAFLD.
Project description:The study investigated the acute effects of meals containing either salmon or veal in combination with carbohydrates with high or low glycemic index (GI) on diet-induced thermogenesis (DIT) (primary endpoint), appetite sensations, and energy intake (EI). Twenty-five overweight men and women ingested four iso-caloric test meals: salmon with mashed potatoes (high GI) (SM), salmon with wholegrain pasta (low GI) (SP), veal with mashed potatoes (VM) and veal with wholegrain pasta (VP). Energy expenditure was measured in the fasting state and six times postprandially for 25 min with 5-min breaks between each measurement. Appetite sensations were measured every 30 min. Blood samples, from arterialized venous blood, were drawn every 20 min until an ad libitum buffet-style lunch was served 3.5 h later. DIT was 40% higher after the SM meal compared to the SP meal (p = 0.002). Prospective food consumption was lower after the SM meal compared with the VP meal (p = 0.01). There were no differences in satiety, hunger, fullness, or ad libitum EI between the test meals (all p > 0.05). In conclusion, salmon with high GI carbohydrates increased DIT compared to salmon with low GI carbohydrates. This indicates that DIT is sensitive to the GI of the carbohydrates after intake of salmon but not veal.
Project description:Aerobic exercise (AEx) exerts antidepressant effects, although the neurobiological mechanisms underlying such effects are not well understood. Reduced brain-derived neurotrophic factor (BDNF) and elevated cortisol have been implicated in the pathophysiology of depression and appear to normalize with antidepressant treatment. Thus, BDNF and cortisol may serve as biological targets for developing AEx as an antidepressant treatment. PURPOSE:This study examined the effects of AEx, of different intensities, on serum BDNF and cortisol in individuals with and without depression. METHODS:Thirteen participants with depression (10 females; age = 27.2 ± 6.9 yr; Montgomery-Äsberg Depression Rating Scale = 21.7 ± 4.7) and 13 control participants (10 females; age 27.2 ± 7.2 yr; Montgomery-Äsberg Depression Rating Scale = 0.5 ± 0.9) participated. Experimental visits consisted of 15 min of low-intensity cycling (LO) at 35% heart rate reserve, high-intensity cycling (HI) at 70% heart rate reserve, or sitting (CON). During each visit, blood samples were obtained at baseline, immediately postexercise (IP), and then every 15 min postexercise for 1 h (15P, 30P, 45P, and 60P). Group, condition, and time differences in BDNF and cortisol were assessed. RESULTS:There were no group differences in cortisol and BDNF. Secondary analysis revealed that BDNF increased in an intensity-dependent nature at IP, and cortisol was significantly elevated at 15P after HI. Changes in BDNF and cortisol showed significant linear relationships with changes in HR. CONCLUSION:HI AEx can elicit acute, transient increases in BDNF and cortisol in young, healthy, and physically active, nondepressed and mild to moderately depressed individuals. This work suggests that AEx has potential to significantly affect the central nervous system function, and the magnitude of such effect may be directly driven by exercise intensity.
Project description:In healthy subjects, it has been suggested that exercise may acutely suppress energy-intake and appetite, with peak intensity being an important determinant for this effect. In subjects with type 2 diabetes (T2D), the effect of exercise on appetite-related variables is, however, virtually unknown. We aimed to assess the effects of two exercise interventions, differing with regards to peak intensity, on energy-intake, satiety and appetite-related hormones in subjects with T2D. Thirteen subjects with T2D completed three 60-min interventions with continuous measurement of oxygen consumption in a randomized and counterbalanced order: (1) Control, (2) Continuous walking (CW; intended 73% of VO2peak), (3) Interval-walking (IW; repeated cycles of 3 min slow [54% of VO2peak] and 3 min fast walking [89% of VO2peak]). Forty-five minutes after completion of the intervention, a 3-h liquid mixed meal tolerance test (MMTT, 450 kcal) with regular satiety assessments and blood samples for appetite-related hormones commenced. An ad libitum meal was served after the MMTT, with subsequent calculation of energy-intake. Moreover, free-living diet records were completed for the following ~32 h. Exercise interventions were well-matched for mean oxygen consumption (CW = 77 ± 2% of VO2peak; IW = 76 ± 1% of VO2peak, P > 0.05). No differences in appetite-related hormones or energy-intake were found (P > 0.05 for all comparisons). IW increased fullness compared to Control shortly after the intervention (P < 0.05) and tended to reduce hunger 2 h into the MMTT compared to CW and Control (P < 0.10). In conclusion, a single exercise session does not affect energy-intake during the following ~4-36 h in subjects with T2D. However, satiety may be affected up to ~3 h after the exercise session, dependent on peak intensity.
Project description:Acute exercise does not elicit compensatory changes in appetite parameters in lean individuals; however, less is known about responses in overweight individuals. This study compared the acute effects of moderate-intensity exercise on appetite, energy intake and appetite-regulatory hormones in lean and overweight/obese individuals.Forty-seven healthy lean (n=22, 11 females; mean (s.d.) 37.5 (15.2) years; 22.4 (1.5) kg?m-2) and overweight/obese (n=25, 11 females; 45.0 (12.4) years, 29.2 (2.9) kg?m-2) individuals completed two, 8 h trials (exercise and control). In the exercise trial, participants completed 60?min treadmill exercise (59 (4)% peak oxygen uptake) at 0-1?h and rested thereafter while participants rested throughout the control trial. Appetite ratings and concentrations of acylated ghrelin, peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) were measured at predetermined intervals. Standardised meals were consumed at 1.5 and 4?h and an ad libitum buffet meal was provided at 7?h.Exercise suppressed appetite (95% confidence interval (CI) -3.1 to -0.5?mm, P=0.01), and elevated delta PYY (95% CI 10 to 17?pg ml-1, P<0.001) and GLP-1 (95% CI 7 to 10?pmol?l-1, P<0.001) concentrations. Delta acylated ghrelin concentrations (95% CI -5 to 3?pg?ml-1, P=0.76) and ad libitum energy intake (95% CI -391 to 346?kJ, P=0.90) were similar between trials. Subjective and hormonal appetite parameters and ad libitum energy intake were similar between lean and overweight/obese individuals (P?0.27). The exercise-induced elevation in delta GLP-1 was greater in overweight/obese individuals (trial-by-group interaction P=0.01), whereas lean individuals exhibited a greater exercise-induced increase in delta PYY (trial-by-group interaction P<0.001).Acute moderate-intensity exercise transiently suppressed appetite and increased PYY and GLP-1 in the hours after exercise without stimulating compensatory changes in appetite in lean or overweight/obese individuals. These findings underscore the ability of exercise to induce a short-term energy deficit without any compensatory effects on appetite regardless of weight status.
Project description:The effect of carbohydrate (CHO) foods on blood glucose (BG) is ranked by their glycemic index (GI). Boiled and mashed potatoes (BMPs) are ranked as high GI foods, whereas pasta and rice have moderate GI rankings. The objective of this study was to compare ad libitum consumption of common CHO dishes consumed with meat on meal-time food intake and post-meal satiety, BG, insulin and gut hormones in 11- to 13-year-old normal weight children.Two randomized crossover studies were conducted. At weekly intervals, children (experiment 1: 12 males (M), 8 females (F); experiment 2: 6M, 6 F) received in random order 1 of 5 CHO side dishes of rice, pasta, BMP, fried French fries (FFF) or baked French fries (BFF) eaten freely together with a fixed amount of lean beef (100 g). In experiment-1, food intake over 30 min and subjective appetite were measured for 120 min. In experiment-2, the same outcomes were measured along with BG, plasma insulin and gut hormones.The results for boys and girls were pooled as sex was not a factor. In both experiments, children consumed 30-40% less calories at meals with BMP (P<0.0001) compared with all other treatments, which were similar. BMP increased satiety, expressed as a change in appetite per kilocalorie, more than all other treatments (P<0.0001). FFF resulted in the lowest (P<0.0001) glucose and insulin at meal end and post-meal and peptide YY (PYY) post-meal. Blood measures were similar among all other treatments.The physiological functions of CHO foods consumed ad libitum at meal time on food intake, appetite, BG, insulin and gut hormone responses in children is not predicted by the GI.