173 research outputs found
Appetite and Energy Intake Responses to Acute Energy Deficits in Females versus Males.
Purpose: To explore whether compensatory responses to acute energy deficits induced by exercise or diet differ by sex. Methods: In experiment one, twelve healthy women completed three 9 h trials (control, exercise-induced (Ex-Def) and food restriction induced energy deficit (Food-Def)) with identical energy deficits being imposed in the Ex-Def (90 min run, ~70% of VO2 max) and Food-Def trials. In experiment two, 10 men and 10 women completed two 7 h trials (control and exercise). Sixty min of running (~70% of VO2 max) was performed at the beginning of the exercise trial. Participants rested throughout the remainder of the exercise trial and during the control trial. Appetite ratings, plasma concentrations of gut hormones and ad libitum energy intake were assessed during main trials. Results: In experiment one, an energy deficit of ~3500 kJ induced via food restriction increased appetite and food intake. These changes corresponded with heightened concentrations of plasma acylated ghrelin and lower peptide YY3-36. None of these compensatory responses were apparent when an equivalent energy deficit was induced by exercise. In experiment two, appetite ratings and plasma acylated ghrelin concentrations were lower in exercise than control but energy intake did not differ between trials. The appetite, acylated ghrelin and energy intake response to exercise did not differ between men and women. Conclusions: Women exhibit compensatory appetite, gut hormone and food intake responses to acute energy restriction but not in response to an acute bout of exercise. Additionally, men and women appear to exhibit similar acylated ghrelin and PYY3-36 responses to exercise-induced energy deficits. These findings advance understanding regarding the interaction between exercise and energy homeostasis in women
Breaking up prolonged sitting time with walking does not affect appetite or gut hormone concentrations but does induce an energy deficit and suppresses postprandial glycaemia in sedentary adults
Breaking up periods of prolonged sitting can negate harmful metabolic effects but the influence on appetite and gut hormones is not understood and is investigated in this study. Thirteen sedentary (7 female) participants undertook three 5-h trials in random order: (i) uninterrupted sitting (SIT), (ii) seated with 2-min bouts of light-intensity walking every 20 min (SIT + LA), and (iii) seated with 2-min bouts of moderate-intensity walking every 20 min (SIT + MA). A standardised test drink was provided at the start of each trial and an ad libitum pasta test meal provided at the end of each trial. Subjective appetite ratings and plasma acylated ghrelin, peptide YY, insulin, and glucose were measured at regular intervals. Area under the curve (AUC) was calculated for each variable. AUC values for appetite and gut hormone concentrations were unaffected in the activity breaks conditions compared with uninterrupted sitting (linear mixed modelling: p > 0.05). Glucose AUC was lower in SIT + MA than in SIT + LA (p = 0.004) and SIT (p = 0.055). There was no difference in absolute ad libitum energy intake between conditions (p > 0.05); however, relative energy intake was lower in SIT + LA (39%; p = 0.011) and SIT + MA (120%; p < 0.001) than in SIT. In conclusion, breaking up prolonged sitting does not alter appetite and gut hormone responses to a meal over a 5-h period. Increased energy expenditure from activity breaks could promote an energy deficit that is not compensated for in a subsequent meal
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
Physical Activity and Hormonal Regulation of Appetite: Sex Differences and Weight Control
Physical activity is an important contributor to regulation of energy balance and body composition. In this article, we separate the impact of exercise from the confounding influence of energy imbalance and highlight sex differences in hormonal and appetite responses to physical activity. The evolving story may influence our thinking regarding the use of physical activity to manage body composition
Prospective Changes in Energy Intake, Physical Activity, and Resting Energy Expenditure during Pregnancy
Background and Purpose: Prenatal changes in energy intake (EI), physical activity (PA), and resting energy expenditure (REE) are important determinants of future health and obesity outcomes. This study examined changes in EI, PA and REE in 16 adult, pregnant women (75% Normal-weight, 15% overweight/obese) early in pregnancy (<16 weeks), mid-pregnancy (24 weeks) and late-pregnancy (32-weeks). Results: From early to mid-pregnancy, women gained an average of 3.7 ± 2.9 kg; EI remained relatively constant (-74 ± 826 kcal/d), PA levels declined by -574 ± 1180 Metabolic Equivalent (METS)*min/wk, and REE increased 122 ± 326 kcal/d. From mid-pregnancy to late-pregnancy, women gained 5.9 ± 2.4 kg; EI increased by 279 ± 352 kcal/d, PA levels increased (460 ± 2000 METS*min/wk) but remained 393 METS*min/wk below early in pregnancy, and REE increased by 251 ± 218 kcal/d. Weight gain trajectories were consistent with IOM recommendations for healthy gestational weight gain (GWG). Conclusions: Findings suggest among women with health GWG, a pattern of gradual and relatively small increases in reported EI and REE is expected, with marginal declines in PA throughout pregnancy. Future research with a larger sample size should identify specific caloric and exercise goals associated with healthy GWG and pregnancy health outcomes
THE EFFECTS OF A UNIFORMLY WEIGHTED EXERCISE SUIT ON BIOMARKERS OF BONE TURNOVER IN RESPONSE TO AEROBIC EXERCISE IN POSTMENOPAUSAL WOMEN WITH LOW BONE DENSITY
Current options for maintaining or slowing aging-related bone mineral density (BMD) loss in postmenopausal women primarily include pharmaceutical agents. More recently, physical activity and exercise have been suggested as highly effective, low cost alternatives. Weighted aerobic exercise, utilizing load carriage systems (LCS), is known to increase the gravitational forces impacting bone, creating a higher osteogenic stimulus than standard aerobic exercise. In response to the positive research on aerobic exercise with well-designed LCS, Dr. Lawrence Petrakis, MD, developed a unique 5.44 kg uniformly weighted exercise suit. This study aimed to examine the effects of the uniformly weighted exercise suit on serum biochemical markers of bone formation (Amino- Propeptide of Type 1 Collagen [P1NP]; Carboxy-Terminal Propeptide of Type 1 Collagen [P1CP] and resorption (Carboxy-Terminal Telopeptide of Type 1 Collagen [CTX]) in response to submaximal aerobic exercise in postmenopausal women with low bone density. Nine volunteer, sedentary to lightly active, healthy postmenopausal women (Age: 58.7±1.1 years, BMI: 28.2±1.0, BMD T-score: -1.2±0.5) participated in this within-subjects study, wherein each participant exercised under two counterbalanced conditions (aerobic exercise with [ES] or without [NS] the exercise suit). During each condition, participants walked on a treadmill at 65%-75% of their age-predicted maximum heart rate until they reached their goal caloric expenditure (400kcal). There was a seven-day washout period between sessions. Serum was processed using ELISA protocols to investigate the change in biomarker at 24 and 72 hours post exercise, relative to baseline. The results indicated, when compared to the NS condition, the ES condition elicited a greater positive change in P1CP at 24 hours (Phours following exercise (P0.05). There was no effect of condition on P1NP at any time point (P\u3e0.05). In sum, submaximal aerobic exercise while wearing the uniformly weighted exercise suit elicited an antiresorptive effect on bone collagen resorption with a simultaneous increase in bone collagen formation 24 hours post exercise
Promoting Weight Loss Before Pregnancy: Feasible or Futile?
Pre-pregnancy obesity is a well-established risk factor for several adverse maternal and fetal outcomes, including gestational diabetes, hypertension, cesarean sections, and fetal macrosomia. Weight loss before pregnancy could help prevent such complications, but the feasibility of such an approach remains unknown. The current study examined the feasibility of a 3-month pre-pregnancy behavioral weight loss program in 12 overweight/obese women planning pregnancy. The 3 month program resulted in an average 5.4 ± 3.0 kg weight loss and significant improvements in self-monitoring, physical activity, eating and exercise self-efficacy, and healthy eating (p \u3c 0.04). By the end of the 9 month follow-up, half of sample (n = 6) had conceived. Women reported significant increases in weekly or more frequent self-weighing (p \u3c 0.0001), counting calories (p \u3c 0.001), consuming fruit and vegetables (p = 0.007), and cutting out fat (p = 0.0001) and junk foods (p = 0.002). A lifestyle modification program to promote weight loss before pregnancy promoted clinically significant weight loss and appeared feasible
Effects of Varying Doses of Oral Bisphenol A Consumption on Type 2 Diabetes Risk Markers in Healthy Adults
Objective
To determine the effects of varying doses of orally administered BPA on indices of glucose metabolism.
Methods
Eleven college students (21.0 ± 0.8 years; 24.2 ± 3.9 kg/m2) were randomized in a double-blinded, crossover fashion separated by \u3e1 week to placebo (PL), deuterated BPA at 4 µg/kg body weight (BPA-4), and deuterated BPA at 50 µg/kg body weight (BPA-50). Total BPA, glucose, insulin, and C-peptide were assessed at baseline, minutes 15, 30, 45, 60, and every 30 minutes for 2 hours in response to a glucose tolerance test.
Results
There was a significant condition × time interaction for total BPA (P \u3c 0.001) such that BPA increased more rapidly in BPA-50 than BPA-4 and PL (P = 0.003) and increased more rapidly in BPA-4 than PL (P \u3c 0.001). There were no significant condition × time interactions on glucose, insulin, and C-peptide. Significant condition main effects were observed for glucose such that BPA-50 was significantly lower than PL (P = 0.036) and nearly lower for BPA-4 vs PL (P = 0.056). Significant condition main effects were observed such that insulin in BPA-50 was lower than BPA-4 (P = 0.021), and C-peptide in BPA-50 was lower than BPA-4 (t18 = 3.95; Tukey-adjusted P = 0.003). Glucose, insulin, and C-peptide areas under the curve for the 3-hour profile were significantly lower in BPA-50 vs PL (P \u3c 0.05).
Conclusion
Orally administered BPA protocol appeared feasible and has immediate effects on glucose, insulin, and C-peptide concentrations
Effects of Cooling During Exercise on Thermoregulatory Responses of Men With Paraplegia.
BACKGROUND: People with spinal cord injury (SCI) have an altered afferent input to the thermoregulatory center, resulting in a reduced efferent response (vasomotor control and sweating capacity) below the level of the lesion. Consequently, core body temperature rises more rapidly during exercise in individuals with SCI compared with people who are able-bodied. Cooling strategies may reduce the thermophysiological strain in SCI. OBJECTIVE: The aim of this study was to examine the effects of a cooling vest on the core body temperature response of people with a thoracic SCI during submaximal exercise. METHODS: Ten men (mean age=44 years, SD=11) with a thoracic lesion (T4-T5 or below) participated in this randomized crossover study. Participants performed two 45-minute exercise bouts at 50% maximal workload (ambient temperature 25°C), with participants randomized to a group wearing a cooling vest or a group wearing no vest (separate days). Core body temperature and skin temperature were continuously measured, and thermal sensation was assessed every 3 minutes. RESULTS: Exercise resulted in an increased core body temperature, skin temperature, and thermal sensation, whereas cooling did not affect core body temperature. The cooling vest effectively decreased skin temperature, increased the core-to-trunk skin temperature gradient, and tended to lower thermal sensation compared with the control condition. LIMITATIONS: The lack of differences in core body temperature among conditions may be a result of the relative moderate ambient temperature in which the exercise was performed. CONCLUSIONS: Despite effectively lowering skin temperature and increasing the core-to-trunk skin temperature gradient, there was no impact of the cooling vest on the exercise-induced increase in core body temperature in men with low thoracic SCI
Randomized intervention trial to decrease Bisphenol A urine concentrations in women: Pilot study
In today\u27s uncertain market and continuously evolving technology, managing manufacturing systems are more complex than ever. This paper studies the dynamics of managing variety and volume to enhance value creation in manufacturers implementing system level advanced and automated manufacturing technology (AAM1). The demand is composed of heterogeneous customers who make purchasing decisions depending on the variety levels and lead times of the firm\u27s product offerings. The cost structure adopted calculates profit as the difference between customer value creation rate (VCR) and costs associated with the process of creating this value. Reported results contribute to the variety and volume management literature by offering analytical clarity of factors affecting product platforms and capacity scalability man agement for systems with AAMT. In addition, insightful answers to the trade offs between profit maximising market coverage and investments, smoothing demand policies and system stability for this type of environment are presented. Furthermore, the value of market information in deciding the industrial technology investment and also the impact of product life cycle on the same investment is captured
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