Exercise-related Energy Research Articles

Similar maximal aerobic capacity but lower energy efficiency during low-to-moderate exercise in women with constitutional thinness: new results from the NUTRILEAN study.

Individuals with constitutional thinness have been presented with a lower muscular energy metabolism at the cellular level but their effective aerobic capacities and exercise-related energy efficiency remains unexplored. The present study compares maximal and sub-maximal aerobic capacities between subjects with constitutional thinness and age-matched normal-weight ones. Anthropometric measures, body composition (Dual-X-ray absorptiometry), physical activity and sedentary time (GT3x actigraphs), and maximal aerobic capacities (cycling 2peak test) were assessed in 18 constitutionally thin (CT-body mass index < 17.5 kg m-2) and 17 normal-weight (NW-body mass index between 20 and 25 kg m-2) women. Energy efficiency was assessed during a submaximal cycling test and a walking exercise. CT had a lower body mass and body mass index compared to NW. Absolute peak oxygen uptake and maximal aerobic power were lower in CT subjects compared to NW (ES: -1.63 [-2.40; -0.86] and -1.32 [-2.05; -0.58], p < 0.001). 2peak related to body mass was not different between groups. Gross and net efficiency (ES: -0.78 [-1.48; -0.06], p = 0.03 and ES: -0.73 [-1.43; -0.01], p = 0.05) were lower in CT compared to NW during the submaximal cycling exercise. The gross energy cost of walking related to body mass was lower in subjects with CT (ES: -1.80 [-2.60; -0.97, p = 0.05), with no difference for the net one. Perceived exertion was similar between groups in responses to both submaximal exercises. Constitutionally thin women do not show impaired aerobic capacities at moderate to maximal intensities despite lower energy efficiency while cycling and walking at low-to-moderate intensities.

No evidence for metabolic adaptation during exercise-related energy compensation

The constrained energy model posits that the increased total daily energy expenditure (TDEE) in response to exercise is often less than the energy cost of the exercise prescribed. The mechanisms behind this phenomenon, coined "exercise-related energy compensation" (ExEC), are poorly understood, and it is unknown if ExEC is coupled with metabolic adaptation. Using a randomized controlled 24-week exercise intervention, individuals who demonstrated ExEC were identified. Changes to all components of TDEE and metabolic adaptation were assessed using doubly labeled water over 14days and room calorimetry over 24-h 48% of individuals exhibited ExEC (-308± 158kcals/day). There were no statistically significant differences in sex, age, or BMI between ExEC and non-ExEC. ExEC was associated with baseline TDEE (r= -0.50, p= 0.006). There were no statistically significant differences in metabolic adaptations for 24 h, sleep, or resting expenditures. These findings reveal that ExEC occurs independent of metabolic adaptation in sedentary components of EE.

39-LB: The Greater the Increase in Physical Activity and Exercise after Metabolic Bariatric Surgery, the Greater the Loss of Fat Mass in Obese Korean Subjects

Object: Exercise after metabolic bariatric surgery (MBS) is known to be more effective in reducing weight, maintaining muscle strength, and improving insulin sensitivity than MBS alone. In this study, we investigated the influence of increment in physical activity and exercise on clinical outcomes after MBS in obese Korean subjects. Method: We recruited 94 patients who underwent MBS from April 2019 to December 2021 prospectively. The levels of physical activity and exercise were collected with self-report questionnaires before and 1 year after MBS. Physical activity- and exercise-related energy expenditure (MET-min/week) was calculated by multiplying the frequency, intensity, and duration of the activities. Patients were classified into non-improved and improved groups according to changes in energy expenditure relative to before surgery. Result: The mean age was 41.4 ± 10.4 years, 38 (40.4%) were male, BMI was 36.9 [32.6, 40.6] kg/m2, and energy expenditure was 438.0 [87.0, 1105.3] MET-min/week at baseline. The improved group had significantly higher BMI (38.0 [34.4, 41.1] vs 33.2 [32.1, 38.8], P = 0.031) and lower MET-min/week (369.8 [174.0, 601.1] vs 761.3 [65.3, 1414.5] METS-min/week, P = 0.045) before surgery. The reduction of BMI and fat mass was significantly greater in the improved group compared with the non-improved group (BMI, 10.2 [8.6, 13.2] vs 9.0 [6.7, 10.9] kg/m2, P = 0.030; fat mass, 25.9 ± 11.1 vs 20.3 ± 9.6 kg, P = 0.016). However, the change in muscle mass was not different between the groups. A greater increase in MET-min/week after MBS was associated with a greater reduction in fat mass after MBS (β = -0.217, P = 0.007), but not with the change in muscle mass. Conclusion: Patients with higher BMI and lower degree of physical activity and exercise were likely to increase their physical activity after MBS. This improvement in physical activity and exercise was associated with more fat mass loss while maintaining muscle mass. Disclosure H. Jang: None. Y. Park: None. J. Moon: None. S. Choi: None. Y. Cho: Consultant; LG Chem. H. Jang: None. T. Oh: None.

The impact of acute exercise on appetite control: Current insights and future perspectives

The interaction of exercise with appetite control and energy intake has been widely studied due to the ability of exercise-related energy expenditure to influence energy and substrate balance. Many empirical studies have explored appetite and energy intake responses to acute (single) exercise bouts involving a variety of protocols in diverse populations revealing several consistent trends. The balance of evidence suggests that acute moderate-to-vigorous intensity land-based exercise suppresses subjective appetite feelings and the orexigenic hormone acylated ghrelin and elevates the anorexigenic hormones peptide YY and glucagon-like peptide-1. These perturbations are transient and hormone concentrations usually return to resting values in the hours after exercise without evoking compensatory increases in appetite or energy intake on the same day. This evidence counters the popular assertion that exercise transiently increases appetite and may prompt greater energy intake at subsequent meals. The indifference of the appetite control system to acute exercise-induced energy deficits contrasts with the immediate increases in appetite and energy intake provoked by equivalent diet-induced energy deficits. There is, however, considerable inter-individual variability in subjective appetite and hormonal responses to acute exercise with some individuals experiencing greater exercise-induced appetite suppression than others. Current evidence supports the promotion of exercise as a strategy for inducing a short-term energy deficit but the relevance of this for long-term appetite regulation and the control of body mass remains uncertain.

Do we need to rethink the determination of exercise-related energy expenditure in cardiac telerehabilitation interventions?

The American College of Sports Medicine determined the energy consumption of daily activities and sports. Cardiac telerehabilitation (CTR) requires knowing how much energy people consume in daily life outside of cardiac rehabilitation activities. Therefore, we have investigated if the estimated values are valid in CTR. Data from two studies were incorporated. The first study measured ventilatory threshold (VT)1, VT2, and peak exercise on cardiopulmonary exercise testing (CPET) collected from 272 cardiac (risk) patients and compared them to the estimated oxygen consumption (VO2) at low-to-moderate-intense exercise (3-6 metabolic equivalents [METs]). Next, a patient-tailored application was developed to support CTR using these estimated values, and the intervention (the second study) was conducted with 24 coronary artery disease patients using this application during a CTR intervention. In the first study, VO2 at VT1, VT2 and peak exercise corresponded to 3.2 [2.8, 3.8], 4.3 [3.8, 5.3], and 5.4 [4.5, 6.2] METs, which are significantly different from the estimated VO2 at low-to-moderate-intense exercise, especially lower in older, obese, female, and post-myocardial infarction/heart failure patients. These VO2 varied considerably between patients. The telerehabilitation study did not show significant progress in peak VO2, but using the application's estimated target, 97.2% of the patients achieved their weekly target, which is a significant overestimate. The estimated and observed exercise-related energy expenditures by CPET were significantly different, resulting in an overestimation of the exercise done by the patients at home. The results can have a significant impact on the quantification of exercise dose during (tele)rehabilitation programs.

Relative energy deficiency in sport: Diagnosis and management in primary care

Relative energy deficiency in sport (RED-S) describes a syndrome that affects multiple bodily systems and functions in both recreational and elite athletes. It is, fundamentally, an imbalance between energy intake and exercise-related energy expenditure, leading to globally impaired physiological function as a result of low energy availability. RED-S developed from the ‘female athlete triad’, describing a relationship between low energy availability (with or without eating disorder), amenorrhea (menstrual dysfunction) and low bone mineral density; it is now recognised to occur across many other bodily systems and also to occur in males. Given its often subtle presentation and consequences early-on, but potentially devastating consequences further down the line, timely recognition and facilitation of management in primary care is crucial to allow safe return to physical activity and to prevent long-term sequelae.

Excess Postexercise Oxygen Consumption Following Isocaloric Bouts of Resistance and Aerobic Exercise in Older Adults

ABSTRACT Purpose: Albeit being a major determinant of exercise-related energy expenditure (EE), there is a lack of research on the excess post-exercise oxygen consumption (EPOC) after different exercise modalities in older adults. This study compared the EPOC after isocaloric bouts of resistance (RE) and aerobic (AE) exercise. Methods: The EE during exercise was determined through telemetric indirect calorimetry in ten physically active participants aged 63 to 82 years (5 women, 73 ± 6 years, 70.5 ± 9.9 kg, 161 ± 8 cm). The target EE in AE corresponded to values achieved during RE, and the EPOC was assessed for 30 min in the supine position. Results: The EE during AE and RE were 126.0 ± 30.7 kcal and 123.9 ± 30.6 kcal, respectively. The time to achieve the target EE was 2.3 times shorter in AE vs. RE. The EPOC magnitude was greater after AE (7.9 ± 2.4 L, 40.1 ± 11.1 kcal) than RE (5.9 ± 1.8 L, 26.9 ± 11.5 kcal). Conclusion: Older adults showed greater EPOC after isocaloric sessions of AE vs. RE. Additionally, AE had better temporal efficiency than RE to elicit a given EE.

A255 INCREASED ENERGY EXPENDITURE AND REDUCED EXERCISE CAPACITY IN CELIAC DISEASE PATIENTS ON A GLUTEN-FREE DIET

Abstract Background Celiac disease (CeD) patients often exhibit impaired nutritional status due to nutrient malabsorption and altered metabolism. Accurate clinical assessment of malnutrition, muscle function and energy requirements are thus essential to prevent and treat malnutrition. Indirect calorimetry (IC) is the most accurate method to measure energy needs, but it is underutilized in outpatient settings. Aims To assess the use of IC testing in estimating the resting energy expenditure and exercise-related energy utilization in treated CeD patients compared to patients with other gastrointestinal (GI) conditions. Methods Adult patients attending the Celiac and Nutrition Clinic at McMaster University that underwent rest and exercise testing as a part of their nutritional assessment were enrolled. CeD diagnosis was based on positive CeD serology and confirmed by biopsy, and all of them were on a GFD for at least 6 months. Patients with inflammatory bowel disease (IBD), functional gastrointestinal disorders (FGID) and undernutrition due to other causes (UN) were included as controls. Resting energy expenditure was assessed using 3 methods 1) predictive formula (25kcal/kg), 2) Harris Benedict and 3) estimation of VO2 by IC. Exercise capacity and energy expenditure (EE) during exercise was estimated at baseline, moderate and maximum exercise. Statistical analysis was performed using SPSS. ANOVA with Bonferroni corrections and Chi2 test were used to assess differences between continuous and categorical variables, respectively. Results A total of 66 patients (CeD n=24; IBD n=15; FGID n=17; UN n=10) were included in the analysis. The REE of GI patients measured using the HB equation and the predictive formula were significantly underestimated compared to IC [Mean Difference (MD)=229 kcal/day p=0.03 and MD=365 kcal/day p&amp;lt;0.001, respectively]. The EE during exercise increased with intensity of exercise. CeD patients had the highest EE during moderate and strenuous exercise (Mean EE = 286 kcal/h and 494 kcal/h respectively) compared to patients with other GI conditions (Moderate and Strenuous for IBD= 218kcal/h and 373kcal/h; for FGIDs 296kcal/hand 467kcal/h, for UN, Mean EE = 181kcal/h and 294kcal/h). Exercise capacity was reduced in CeD compared to predicted exercise capacity (Mean = 86% predicted work capacity, range 72.5–107%), but was significantly higher than IBD (86% vs 73%; p=0.65) and UN patients (86% vs 46%; p=0.004). Conclusions Increased energy consumption and reduced exercise capacity is suggestive of chronic impaired nutritional status in treated CeD patients. Future studies with larger sample sizes are needed to understand whether incorporating accurate estimations of energy expenditure in nutritional practices can improve CeD outcomes. Funding Agencies CAG

Low energy availability and impact sport participation as risk factors for urinary incontinence in female athletes

Relative Energy Deficiency in Sport (RED-S) is a clinical syndrome that includes the many complex health and performance consequences of low energy availability (EA) in athletes, when there is insufficient caloric intake to meet exercise-related energy expenditure and to support basic physiologic functions. There is a high prevalence of urinary incontinence (UI) in female athletes and it is more common in female athletes than non-athletes. The objective of this study was to determine if low EA is associated with UI in a population of adolescent and young adult female athletes and to evaluate for an association between sport categories and UI. 1000 nulliparous female patients, ages 15-30 years, presenting to a sports medicine subspecialty clinic, provided informed consent/assent to participate in a cross-sectional study involving a comprehensive survey, anthropomorphic measurements, and medical record review. Low EA was defined as meeting ≥1 criterion: self-reported history of eating disorder/disordered eating (ED/DE), and/or a high score on the Brief Eating Disorder in Athletes Questionnaire (BEDA-Q), and/or a high score on the Eating Disorder Screen for Primary Care (ESP). UI was assessed using questions adapted from the International Consultation on Incontinence-Urinary Incontinence Short Form (ICIQ-UI-SF), questions regarding timing of UI onset/duration, and a binary question regarding UI during sport activities. A total of 36 sport types were included in the survey and sub-divided into categories. Of the 1000 female athletes surveyed, 165 (16.5%) reported a history of experiencing UI during athletic activities. ICIQ- UI-SF responses indicated that 14% (137/1000) of the cohort experienced slight incontinence, 4% (35/1000) moderate incontinence, and 2 athletes experienced severe incontinence. There was a significant difference between UI categories in age (p=0.01), low EA (p<0.001), and sport category (p<0.001). Females who had low EA had twice the likelihood (OR=1.97; 95% CI=1.39 to 2.81; p<0.001) of UI compared to those with adequate EA, controlling for sports category and menstrual dysfunction. Females who participated in high impact sports were 4.5 times more likely (OR=4.47; 95% CI=2.29 to 8.74; p<0.001) to have had UI compared to females who participated in ball sports, controlling for EA and menstrual dysfunction. UI during athletic activities is a common problem among nulliparous adolescent and young adult female athletes, occurring in 16.5% of female athletes surveyed. UI was significantly associated with low EA across all sport categories. Sport type was significantly associated with UI, with the highest impact sport group demonstrating a higher prevalence and symptom severity compared to other sport categories.

The Impact of Dietary Supplement NT-020 with Rhodiola Rosea on Energy, Fatigue, and Perceived Exertion

Purpose: Evaluate the effectiveness of a commercially-available nutraceutical product on levels of exercise-related energy, fatigue, and exertion before and after 4 weeks of supplementation. Primary ingredients within the product include a proprietary blend of blueberry extract, green tea extract, L-carnosine, and Vitamin D3 (NT-020) and rhodiola rosea, a plant that purports to boost energy.Methods: Twenty-seven participants (12 female, 15 male, mean BMI = 23) completed baseline assessment of aerobic fitness (mean VO2 peak = 40 mL x kg-1 x min-1) before being randomized into a placebo or supplement condition for four weeks. All participants were involved in regular physical activity three or more days per week. Assessment of energy, fatigue, and perceived exertion responses during and immediately following moderately intense cycle ergometry exercise was conducted before and after the 4-week ingestion period during which participants were instructed to maintain existing exercise activities.Results: Data were analyzed by way of repeated measures ANOVA and dependent t-tests to determine the presence of significant differences across time and between the supplement and placebo conditions. Participants receiving the supplement reported: greater levels of energy and lower levels of fatigue during the initial moments after completing the exercise trial (p &lt; 0.05), greater levels of energy at the midpoint of the exercise trial (p &lt; 0.05) but not at the end of the exercise session (p &gt; 0.05), and lower perceived exertion at four of the six measurement points during exercise (p &lt; 0.05). No differences were observed from pre to post intervention within the placebo condition (p &gt; 0.05).Conclusions: Findings indicate that a commercially available supplement marketed to boost energy and reduce fatigue can deliver the purported benefits at least in part. Related findings that supplementation for a 4-week period can allow for equal work at a lower rating of perceived exertion provides further, though limited support that this product may have efficacy.

The effect of energy-matched exercise intensity on brain-derived neurotrophic factor and motor learning.

Pairing a bout of high-intensity exercise with motor task practice can enhance motor learning beyond task practice alone, which is thought, in part, to be facilitated by an exercise-related increase in brain-derived neurotrophic factor (BDNF). The purpose of the current study was to examine the effect of different exercise intensities on BDNF levels and motor learning while controlling for exercise-related energy expenditure. Forty-eight young, healthy participants were assigned to one of three groups: high-intensity exercise [High], low-intensity exercise [Low], or quiet rest [Rest]. The duration of the exercise bouts were individually adjusted so that each participant expended 200 kcals regardless of exercise intensity. BDNF was measured before and after exercise or rest. After exercise or rest, all participants practiced a 3-dimensional motor learning task, which involved reach movements made to sequentially presented targets. Retention was tested after 24-h. BDNF genotype was determined for each participant to explore its effects on BDNF and motor learning. All participants equally improved performance, indicated by a reduction in time to complete the task. However, the kinematic profile used to control the reach movement differed by group. The Rest group travelled the shortest distance between the targets, the High group had higher reach speed (peak velocity), and the Low group had earlier peak velocities. The rise in BDNF post-exercise was not significant, regardless of exercise intensity, and the change in BDNF was not associated with motor learning. The BDNF response to exercise did not differ by genotype. However, performance differed between those with the polymorphism (Met carriers) and those without (Val/Val). Compared to the Val/Val genotype, Met carriers had faster response times throughout task practice, which was supported by higher reach speeds and earlier peak velocities. Results indicated that both low and high-intensity exercise can alter the kinematic approach used to complete a reach task, and these changes appear unrelated to a change in BDNF. In addition, the BDNF genotype did not influence BDNF concentration, but it did have an effect on motor performance of a sequential target reach task.

High intensity, circuit-type integrated neuromuscular training alters energy balance and reduces body mass and fat in obese women: A 10-month training-detraining randomized controlled trial.

This randomized controlled trial examined body mass, body composition, energy balance and performance responses of previously sedentary overweight/obese women to a circuit-type integrated neuromuscular training program with alternative modalities. Forty-nine healthy overweight or class I obese females (36.4±4.4 yrs) were randomly assigned to either a control (N = 21), training (N = 14) or training-detraining (N = 14) group. In weeks 1–20, the training groups trained three times/week using 10–12 whole-body exercises of progressively increased intensity/volume, organized in timed interval circuit form. In weeks 21–40, the training group continued training whereas the training-detraining group not. Heart rate, perceived exertion, blood lactate, exertion, oxygen consumption and excess post-exercise oxygen consumption were measured for one session/phase/person and exercise energy expenditure was calculated. Energy intake, habitual physical activity, resting metabolic rate, body composition, body mass, strength and maximal oxygen consumption were measured at baseline, mid-intervention and post-intervention. A two-way repeated measures ANOVA was used to determine differences between three time points and three groups. In C, VO2max declined (p<0.013) and body fat (p<0.008), waist (p<0.059) and hip (p<0.012) circumferences increased after 40 weeks compared to baseline. Training reduced body mass (6%, p<0.001), body fat (~5.5%, p<0.001) and increased fat-free mass (1.2–3.4%, p<0.05), strength (27.2%, p<0.001) and endurance (26.8%, p<0.001) after a 10-month implementation period using a metabolic overload of only 5–12 metabolic equivalents of task-hours per week. Training induced a long-term negative energy balance during an exercise and a non-exercise day due to an elevation of resting metabolic rate (6%-10%, p<0.05) and exercise-related energy expenditure. Training had an 8% and 94% attrition and attendance rates, respectively. Training-induced gains were attenuated but not lost following a 5-month detraining. A 10-month implementation of a high-intensity interval type training program elicited both endurance and musculoskeletal gains and resulted in a long-term negative energy balance that induced a progressive and sustained reduction of body and fat mass.Trial Registration: ClinicalTrials.gov NCT03134781

Exercise Predicts Long-Term Weight Loss in Women With Class 1 and Class 2 Obesity Through Effects on Emotional Eating and its Correlates.

The relationship between exercise and long-term weight loss is definitive. However, in deconditioned individuals, the basis of that relationship beyond minimal energy expenditures is unclear. Effects emanating from exercise's proposed association with changes in emotional eating and its psychosocial correlates were tested. Women with class 1 (n = 67) and class 2 (n = 53) obesity, participating in a new community-based weight-loss treatment based on tenets of social cognitive theory, were assessed at baseline and Months 3, 6, 12, and 24 on weight and measures of exercise outputs, emotional eating, eating self-regulation, and negative mood. An exercise-support component was provided for 2 months prior to group nutrition-change sessions. Improvements from baseline were significant on all measures but did not significantly differ by group. Although not for the initial 3 months, changes in exercise significantly predicted weight changes over 6, 12, and 24 months from baseline. However, only 26%-31% of the lost weight was directly attributable to exercise-related energy expenditures. Changes in emotional eating significantly mediated the exercise-weight-loss relationship, and changes in self-regulation and mood significantly mediated the exercise-emotional eating relationship. Findings supported exercise's role in long-term weight loss primarily through psychosocial factors.

Effect Of A Nutraceutical Product On Energy, Fatigue, And Perceived Exertion In Healthy Active Adults

PURPOSE: Evaluate the effectiveness of a commercially available nutraceutical product on levels of exercise-related energy, fatigue, and exertion before and after 4 weeks of supplementation. Primary ingredients within the product include a proprietary blend of blueberry extract, green tea extract, L-carnosine, and Vitamin D3 (NT-020) and rhodiola rosea, a plant that purports to boost energy. METHODS: Twenty-seven participants (12 female, 15male, mean BMI = 23) completed baseline assessment of aerobic fitness (mean VO2 peak = 40 mL x kg-1 x min-1) before being randomized into a placebo or supplement condition for four weeks. All participants were involved in regular physical activity three or more days per week. Assessment of energy, fatigue, and perceived exertion responses during and after moderately intense cycle ergometry exercise was conducted before and after the 4-week ingestion period during which participants were instructed to maintain existing exercise activities. RESULTS: Data were analyzed by way of repeated measures ANOVA and dependent t-tests to determine the presence of significant differences across time and between the supplement and placebo conditions. Participants receiving the supplement reported: greater levels of energy and lower levels of fatigue during the initial moments after completing the exercise trial (p < 0.05), greater levels of energy at the midpoint of the exercise trial (p < 0.05) but not at the end of the exercise session (p > 0.05), and lower perceived exertion at four of the six measurement points during exercise (p < 0.05). No differences were observed from pre to post intervention within the placebo condition (p > 0.05). CONCLUSIONS: Findings indicate that a commercially available supplement marketed to boost energy and reduce fatigue can deliver the purported benefits at least in part. Related findings that supplementation for a 4-week period can allow for equal work at a lower rating of perceived exertion provides further, though limited support that this product may have efficacy.

The Female Athlete Triad.

The number of girls participating in sports has increased significantly since the introduction of Title XI in 1972. As a result, more girls have been able to experience the social, educational, and health-related benefits of sports participation. However, there are risks associated with sports participation, including the female athlete triad. The triad was originally recognized as the interrelationship of amenorrhea, osteoporosis, and disordered eating, but our understanding has evolved to recognize that each of the components of the triad exists on a spectrum from optimal health to disease. The triad occurs when energy intake does not adequately compensate for exercise-related energy expenditure, leading to adverse effects on reproductive, bone, and cardiovascular health. Athletes can present with a single component or any combination of the components. The triad can have a more significant effect on the health of adolescent athletes than on adults because adolescence is a critical time for bone mass accumulation. This report outlines the current state of knowledge on the epidemiology, diagnosis, and treatment of the triad conditions.

Impact of Small Monetary Incentives on Exercise in University Students.

Research has demonstrated that health outcomes are significantly improved with the application of financial incentives. However, relatively larger incentives are not typically sustainable and removal of incentives tends to result in attrition of behavior. The feasibility of using relatively smaller incentives to improve physical activity is unclear. The aim of the present study is to determine whether small financial incentives (maximum $5.00 per week) can improve exercise-related energy expenditure of inactive individuals. Twenty-two university students (20 ±1.6 years old) were randomized into incentive or non-incentive conditions. Exercise-related caloric expenditure was tracked over 10 weeks. The sample size yielded 62% power. The repeated measures ANCOVA, controlling for body mass index, indicated a main effect of condition (F = 5.50, p =.03) with no significant interaction (F = 2.25, p = .06). This pilot study demonstrates initial feasibility in implementing small financial incentives to promote exercise behavior in previously inactive young adults. Due to the small sample size, results should be interpreted with caution and further research is warranted to improve and maintain exercise behavior in response to relatively smaller incentives.

Cord blood irisin levels are positively correlated with birth weight in newborn infants

BackgroundIrisin is a novel myokine, secreted from skeletal muscle after exercise. Irisin mediates exercise-related energy expenditure by turning white adipose tissue (WAT) into brown adipose tissue (BAT). Thus, irisin is considered as a potential biomarker for obesity and metabolic syndrome. Infants born small for gestational age (SGA) have increased risk for metabolic syndrome. However, the physiologic role of irisin in neonates remains to be studied. ObjectiveTo evaluate the association of umbilical cord blood irisin levels with gestational age and birth weight categories in neonates. MethodsA cross-sectional study of 341 newborns, from 26 to 41weeks’ gestation. We collected umbilical cord blood and analyzed plasma for irisin by ELISA. ResultsPlasma irisin levels were positively correlated with gestational age (r=0.21, p<0.001), and birth weight Z-score (r=0.18, p<0.001). SGA infants had significantly lower irisin (median [interquartile range] 55.38 [46.56–65.72]ng/mL) compared to appropriate for gestational age infants (64.41 [53.87–76.76]ng/mL) and large for gestational age infants (68.70 [54.78–79.09]ng/mL, p<0.01). The association between SGA and lower irisin remained significant in multivariate analysis independent of gestational age, maternal age, maternal BMI, and gestational diabetes (p=0.03). In singleton infants, irisin was also significantly negatively associated with maternal preeclampsia (p=0.01). ConclusionsOur results support the notion that irisin may have a physiologic role in neonates. We speculate that decreased levels of irisin in SGA infants may contribute to the development of catch-up growth and metabolic syndrome later in life.

Effect of the low- versus high-intensity exercise training on endoplasmic reticulum stress and GLP-1 in adolescents with type 2 diabetes mellitus.

[Purpose] The primary objective of this study was to investigate the effect of low-intensity exercise training compare with high-intensity exercise training on endoplasmic reticulum stress and glucagon-like peptide-1 in adolescents with type 2 diabetes mellitus. [Subjects and Methods] The low-intensity exercise training group performed aerobic exercise training at an intensity of ≤ 45% of the heart rate reserve. The high-intensity interval exercise training group performed interval exercise training at an intensity of ≥ 80% of the heart rate reserve. The exercise-related energy consumption was determined for both groups on a per-week basis (1,200 kcal/week). [Results] Both groups showed improvement in the glucose-regulated protein 78 and dipeptidyl peptidase-4, but the size of the between-group effect was not statistically significant. The high-intensity interval exercise training group showed a significant reduction in percentage body fat. The C-peptide level increased after the 12-weeks programs and was significantly different, between the groups. Fasting glucose, insulin resistance in the fasting state according to homeostasis model assessment, and leptin decreased after the 12-weeks exercise program and were significantly different between the groups, and glucagon-like peptide-1 increased after the 12-week exercise programs and was significantly different between the groups. [Conclusion] In conclusion high-intensity interval exercise training, as defined in this study, may lead to improvements in body composition, glycemic control, endoplasmic reticulum stress, and the glucagon-like peptide-1 in adolescents with type 2 diabetes mellitus.

Recommending self-paced exercise among overweight and obese adults: a randomized pilot study.

National guidelines call for exercise of at least moderate intensity; however, recommending self-paced exercise may lead to better adherence, particularly among overweight and obese adults. The purpose of this study was to test proof-of-concept for recommending self-paced exercise among overweight adults. Fifty-nine healthy, low-active (exercise <60min/week), overweight (body mass index 25.0-39.9) adults (18-65) received a 6-month print-based exercise promotion program with the goal of walking 30-60min/day. Participants were surreptitiously randomly assigned to receive a recommendation for either self-paced (n = 30) or moderate (64-76% maximum heart rate; n = 29) intensity exercise. All participants used electronic diaries and heart rate monitors to track exercise frequency, duration, and intensity. The self-paced condition reported more minutes/week of walking (f (2) = 0.17, p = 0.045) and a trend toward greater exercise-related energy expenditure/week (f (2) = 0.12, p = 0.243), corresponding to approximately 26 additional minutes/week and 83 additional kilocalories/week over 6months. Explicit recommendation for self-paced exercise may improve adherence to exercise programs among overweight and obese adults.

Long-term effect of different physical activity levels on subclinical atherosclerosis in middle-aged men: a 25-year prospective study.

BackgroundThe purpose of the study was to investigate the influence of lifetime physical activity (PA) on selected indices of atherosclerosis in longitudinal observation of middle-aged men.MethodsThe subject of the study was a cohort of 101 men (mean age 59,7±9,0 years), free of cardiovascular symptoms and treatment, participating in follow-up examinations in the years 1985/90-2011/12. Self-report PA was assessed by interviewer-administered Seven-Day PA Recall and Historical PA questionnaire. Subclinical atherosclerosis was measured by assessing the coronary artery calcification (CAC) according to Agatston's method using multi-slice computed tomography; the carotid intima-media thickness (IMT) using high-resolution B-mode ultrasound; and the reactive hyperemia index (RHI) using peripheral arterial tonometry (EndoPAT2000). The participants were initially divided into three groups according to tertiles of exercise-related energy expenditure (EE) in kcal/week at baseline, i.e. <2050 (low-to-moderate; n = 33), 2050–3840 (high; n = 34), >3840 (very high; n = 34).ResultsThe low-to-moderate, high and very high PA groups were comparable in terms of age and atherosclerosis risk factors at baseline. No linear relationship was found between PA and CAC, IMT and RHI. Men who maintained low-to-moderate (n = 26), high (n = 21) and very high (n = 15) PA level had the mean CAC of 286.1±361.9, 10.7±28.9, and 106.1±278.3 (p<0.001 for low-to moderate vs high; p<0.05 for low-to-moderate vs very high); the mean IMT of 0.751±0.19 mm, 0,641±0.26 mm, and 0.750±0.60 mm (p>0.05); and the mean RHI of 1.69±0.4, 2.00±0.4, and 2.13±0.5 (p for trend = 0.050), respectively. No cases of CAC>400, IMT ≥0.9 and RHI<1.67 were noted only among men with maintained high PA level. At final examination men with high and very high PA had more favorable cardiometabolic profile than men with lower PA.ConclusionsMaintaining regular high PA level through young and middle adulthood may protect against atherosclerosis as measured by CAC, IMT and RHI.