Basal metabolism of obese adolescents: inconsistent diet and exercise effects

Effects of 20 wk of diet-plus-behavior (DB) therapy or exercise-plus-diet-plus-behavior (EDB) therapy on changes in basal energy expenditure (BEE) were studied in 36 obese male and female adolescents. BEE was assessed by open-circuit spirometry and body composition by hydrostatic weighing. Dietary restriction was based on the dietary-exchange program. Behavioral treatment included record-keeping, stimulus-control, and reinforcement techniques. EDB therapy included 50 min/d, 3 d/wk of aerobics. A time-by-group (2 X 3) repeated-measures ANOVA was used to analyze pre-to-postintervention differences between groups (DB, EDB, and control). Results revealed small but statistically significant (p less than 0.05) differences in body composition between the two experimental groups and control subjects. There were no differences in body composition between the DB and EDB groups, although all control subjects gained body mass (p less than 0.05). There was no group-by-time interaction for BEE. Moderate correlations of r = less than or equal to 0.61 were obtained between change in BEE and change in body composition for the subjects in the experimental groups.     

The effects of aerobic exercise on psychological adjustment: a randomized study of sedentary obese women attempting weight loss.

This study evaluated the psychological effects of aerobic conditioning in 40 moderately obese, sedentary women participating in a 12-week behavioral weight loss program. Participants were randomly assigned to a no-exercise or moderate walking condition. Emotional impact of the treatment was assessed in two ways: (1) Subjects reported subjective mood prior to each eating episode and (2) the SCL-90-R was administered before and after the program. Exercisers lost more weight and body fat than non-exercisers. Both groups of subjects showed numerous improvements in mood as a result of participating in the weight loss program. Exercise had no specific differential effect on emotions as measured by daily mood ratings or the SCL-90-R. Exercise did not appear to add appreciably to the psychological benefits of losing weight in this sedentary obese population. Future studies utilizing longer periods of aerobic exercise training, larger sample size, and exercise specific measures are recommended.     

Combined effects of aerobic exercise and high-carbohydrate meal on plasma acylated ghrelin and levels of hunger

The present study investigated the effect of an aerobic exercise bout associated with a high-carbohydrate (CHO) meal on plasma levels of acylated ghrelin and hunger sensation. Eight healthy males performed an exercise (ET) and a control (CT) trial. In ET, participants performed a 60-min cycling exercise (～70% of maximal oxygen uptake) after consuming a high-CHO meal. In the CT, participants remained at rest throughout the whole period after consuming the high-CHO meal. Hunger sensation was assessed and blood samples were taken to determine the levels of acylated ghrelin, glucose, insulin, total cholesterol (TC), and triglycerides (TG). There was suppression of hunger after consuming the meal in ET and CT (p = 0.028 and p = 0.011, respectively). Hunger increased in CT in the period correspondent to the exercise session (p?= 0.017) and remained suppressed in the ET. The area under the curve for acylated ghrelin showed that its levels were lower in the ET compared with CT in the period of the exercise plus the immediate period (1?h) postexercise (60.7 vs. 96.75 pg·mL(-1)·2?h(-1), respectively; p = 0.04). Inverse correlations between acylated ghrelin levels and insulin, TC, and TG levels at different time points were observed. In conclusion, these findings suggest that 1 bout of aerobic exercise maintains the meal-induced suppression of hunger. The mechanism underlying this effect may involve the exercise-induced suppression of acylated ghrelin. These results implicate that the combination of a high-CHO meal and aerobic exercise may effectively improve appetite control and body weight management.     

Acute effects of exercise on food intake in obese and nonobese women

The animal model of exercise-induced anorexia was employed in humans to develop a laboratory paradigm for studying the acute effect of exercise on food intake. Each of nine obese and nine nonobese women exercised either strenuously (90 W) or moderately (30 W) on a cycle ergometer for 40 min or rested in the laboratory on each of 3 nonconsecutive days. Intake of a liquefied test meal (1.04 kcal/g) eaten 15 min after exercise was significantly less after the strenuous (620 g) than after the moderate (754 g) exercise in the nonobese women but was no different after the two conditions (532 g after strenuous, 581 g after moderate) in the obese women. Heart rate and energy expenditure were increased in proportion to the exercise by the same amount in both groups. The results demonstrate for the first time that food intake is reduced immediately after strenuous exercise in nonobese women, as it is in animals, and validate the feasibility of this laboratory paradigm.     

Fiber and exercise in the treatment of obese adolescents

The changes in body weight, body fat, lean body mass, and the efficiency index were studied in a sample of 80 obese males and females undergoing four different treatments, using two treatment components: an increase in dietary fiber, and energy expenditure through exercise. In both sexes there was a significant effect of exercise upon body weight and an improvement in the efficiency index. There was also a significant interaction between fiber and exercise in girls, but not in boys. This suggests that the eventual effect of dietary fiber is heightened by exercise, as corroborated by significant differences in some of the groups.     

Knee extension strength in obese and nonobese male adolescents

The aim of the present study was to compare "absolute" and "relative" knee extension strength between obese and nonobese adolescents. Ten nonobese and 12 severely obese adolescent boys of similar chronological age, maturity status, and height were compared. Total body and regional soft tissue composition were determined using dual-energy X-ray absorptiometry (DXA). Knee extensors maximum voluntary contraction (MVC) torque was measured using an isometric dynamometer at a knee angle of 60° (0° is full extension). Absolute MVC torque was significantly higher in obese adolescents than in controls. However, although MVC torque expressed per unit of body mass was found to be significantly lower in obese adolescent boys, no significant difference in MVC torque was found between groups when normalized to fat-free mass. Conversely, when correcting for thigh lean mass and estimated thigh muscle mass, MVC torque was significantly higher in the obese group (17.9% and 22.2%, respectively; P <0.05). To conclude, our sample of obese adolescent boys had higher absolute and relative knee extension strength than our nonobese controls. However, further studies are required to ascertain whether or not relative strength, measured with more accurate in vivo methods such as magnetic resonance imaging, is higher in obese adolescents than in nonobese controls.     

Acute and protocol-dependent effects of aerobic exercise on neurobiochemical indices and neuropsychological performance of working memory

This study aimed to clarify the effects of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) protocols on peripheral neurotransmitters and on the neuropsychological performance of working memory and to explore underlying correlations. In a randomised cross-over trial, twenty-two adults in late middle age or older completed a single session of HIIE, MICE, or a control condition (rest) in counterbalanced order with a 7-day washout. Neuropsychological indices of working memory and neurotransmitter (norepinephrine, dopamine, and serotonin) levels were measured at baseline and after an intense bout of either HIIE or MICE, or an intervention without exercise. Analyses of the results revealed no significant effect of HIIE on the neurotransmitters, but significantly high levels of norepinephrine and serotonin were induced by MICE. In terms of neuropsychological performance, a single session of HIIE and MICE shortened the participants' reaction times (RTs), whereas only MICE caused a significant increase in accuracy rates (ARs). Significant correlations were found between the changes in norepinephrine levels and ARs/RTs before and after the HIIE and MICE interventions, respectively. The results of this study suggest that an intense MICE protocol triggers higher norepinephrine and serotonin levels than HIIE does. The possible neurobiochemical factor (i.e., norepinephrine) underlying the HIIE/MICE-induced neuropsychological benefits (i.e., improved ARs and RTs) for working memory encoding and maintenance appears to be protocol-dependent. Systematic and prolonged investigations are required to further understand the effects/mechanisms specific to each exercise protocol in order to optimize the benefits of aerobic exercise interventions for long-term neurobiochemical and neuropsychological health.     

Weight control among obese adolescents: a pilot study

OBJECTIVE: The present study evaluated weight loss and compliance outcomes for overweight adolescents assigned to one of two dietary interventions differing in the type of snacks allowed. METHODS: The study was a 12-week, controlled clinical trial, among otherwise healthy but overweight (body mass index >or=95th percentile) 11-year-old to 15-year-old girls who were randomly assigned to either a 1,500 kcal/day free-snack program or a 1,500 kcal/day restricted-snack program. All subjects were counseled to consume three servings of dairy products per day, and were provided with a 500 mg calcium supplement as well. Subjects in the free-snack group could choose any 150-calorie item as one of their two daily snacks, including regular soda if desired; however, subjects in the restricted-snack group were limited to diet soda. RESULTS: Thirty-two adolescent girls completed the 12-week intervention. Both diets were equally effective in achieving a modest amount of weight loss, and were equally acceptable to the subjects. Significant decreases in weight, body mass index, anthropometric measures, total cholesterol and triglycerides were observed. CONCLUSIONS: A 1,500 kcal/day diet allowing for a free snack of 150 calories was equally as effective as a more restricted snack policy in achieving a modest amount of weight loss among overweight 11-year-old to 15-year-old girls. In addition, results suggest that some soda may be included in a teen weight control diet, as long as caloric intake is maintained at recommended levels, and care is taken to achieve adequate intake of essential nutrients. Calcium intake among subjects was low at baseline, and, although it increased during the study (due to supplementation), further efforts to increase consumption of naturally calcium-rich and calcium-fortified foods and beverages are needed.     

体育锻炼动机对青少年运动量及有氧适能的影响

探讨动机理论视角下体育锻炼对青少年运动量及有氧适能的影响,为促进青少年身心健康提供依据.方法 随机选取青岛市3所中学共1 122名学生,采用体育锻炼动机问卷对研究对象体育锻炼动机进行量化,根据《国家学生体质健康标准》对学生有氧适能进行评价,按照运动训练学计算学生运动负荷,观察动机、有氧适能、运动负荷之间的内在相关性及动机对另外两者的预测作用.结果 被试体育锻炼动机5个维度与有氧适能、运动量整体得分之间相关均有统计学意义(P值均<0.05),但外貌维度与体育锻炼时间、次数,健康维度与体育锻炼次数,锻炼强度与有氧适能,锻炼次数与锻炼时间相关均无统计学意义(P值均>0.05);体育锻炼动机各维度对运动量具有预测作用,预测能力从大到小依次为能力(B=0.320)、愉快(B=0.312)、关联(B=0.269)、健康(B=0.258)、外貌(B=0.156);体育锻炼动机对其有氧适能也存在预测价值,但5个维度中仅愉快(B=0.145)、能力(B=0.214)、关联(B=0.176)存在预测价值;运动量对有氧适能有预测价值(B=0.171,P<0.01).结论 通过激发青少年体育锻炼动机,可以强化其运动量,提高身体有氧适能水平,最终促进青少年体育锻炼和体质水平的提高.     

运动干预对超重肥胖儿童青少年身体成分影响的网状Meta分析

目的 采用网状Meta分析方法比较有氧、抗阻、有氧结合抗阻3种运动方式对超重/肥胖儿童、青少年身体成分的影响,为儿童青少年超重/肥胖干预研究和实践提供更全面有效的证据.方法 检索中国知网、维普网、万方、PubMed、Web of Science数据库公开发表的与"运动干预对超重/肥胖儿童青少年体成分"相关的随机对照试验...     

Positive effects of a qigong and aerobic exercise program on physical health in elderly Japanese women: an exploratory study

Objective To determine the effects of a 12-week qigong and aerobic exercise program on the physical well-being of relatively healthy elderly Japanese women. Methods In the first study, 72 elderly Japanese women who were relatively healthy and naive to qigong completed the 12-week qigong and aerobic exercise program. Physical function, body composition, and abdominal fat were evaluated. In the second study, we examined the effects of qigong alone on physical function. Twenty-nine participants in each of two groups (divided according to their residences) underwent a 12-week program: qigong and aerobic exercise (residents in Yura Town) or qigong exercise alone (residents in Mihama Town). Results In the first study, physical function including lung capacity, trunk bending, normal walking for 30 m, and rising from a supine position significantly improved after the 12-week program. In addition, body fat diminished significantly during the program. In the second study, both exercise programs (“qigong and aerobic” and “qigong alone”) similarly increased walking speed (normal and maximum walking) and rising speed. Conclusions The findings of this exploratory study demonstrated that a 12-week qigong and aerobic exercise program was associated with improvements in physical function and a reduction in body fat. The qigong exercise program alone positively influenced physical function. The qigong program appears to be an appealing means of improving the physical health of elderly persons.     

Relations of mood and exercise with weight loss in formerly sedentary obese women

Objective: To assess relations of mood changes, exercise, and weight loss among formerly sedentary obese women (N=76; Mean BMI=36.6) reporting weight loss goals. Methods: At baseline and month 6, participants completed the Profile of Mood States scales of depression, tension, and total mood disturbance and were assessed on attendance in exercise sessions and changes in weight. Results: Significant positive correlations were found between weight changes and each mood factor at baseline (r=.31 to .40) and changes from baseline to month 6 (r=.41 to .47). Multiple regression analyses suggested exercise attendance and mood changes significantly contributed to explained variances in weight changes (R(2)=.22 to .28). Conclusions: Mood factors and incorporation of exercise may have implications for health behavior theory and weight loss treatments.     

Effects of aerobic,resistance, and combined exercise training on insulin resistance markers in overweight or obese children and adolescents: A systematic review and meta-analysis

ObjectiveTo assess the associations of aerobic, resistance, and combined exercise with changes in insulin resistance, fasting glucose, and fasting insulin in children and adolescents who are overweight or obese.Data SearchesMEDLINE via Pubmed, Cochrane-CENTRAL, SPORTDiscus, and LILACS.Study SelectionRandomized clinical trials of at least six weeks of duration that evaluated the ability of exercise training to lower at least one of the following outcomes: insulin resistance-HOMA, fasting glucose, and fasting insulin in children and/or adolescents classified as obese or overweight.Data Extraction and analysisTwo independent reviewers extracted data and assessed the quality of the included studies. Differences (exercise training group minus control group) in the outcomes evaluated were analyzed using a random effects model.ResultsOf 1853 articles retrieved, 17 studies were included. The meta-analysis showed that physical training in general was not associated with a reduction in fasting glucose levels compared to the control, but it was associated with reductions in fasting insulin levels (− 3.37 μU/ml; CI 95%, − 5.16 μU/ml to − 1.57 μU/ml; I², 54%, p = 0.003) and HOMA (− 0.61; CI 95%, − 1.19 to − 0.02; I², 49%, p = 0.040). In addition, each modality (aerobic, resistance, and combined) was compared to the control group. Aerobic exercise was associated with declines in fasting insulin levels (− 4.52 μU/ml; CI 95%, − 7.40 to − 1.65; I², 65%, p = 0.002) and in HOMA (− 1.33; 95% confidence interval, − 2.47 to − 0.18; I², 73%, p = 0.005).ConclusionsExercise training, especially aerobic training, is associated with the reduction of fasting insulin levels and HOMA in children and adolescents with obesity and overweight, and may prevent metabolic syndrome and type 2 diabetes.     

力量训练对肥胖初中男生心血管自主神经功能的调节

目的观察8周力量训练对肥胖男性青少年自主神经功能的调节作用,为制定特异性的运动处方提供依据。方法将郑州市某中学24名单纯性肥胖男生随机分为安静对照组(RC)和力量训练组(ST),每组12人。RC组维持正常生活习惯,ST组进行为期8周的力量训练。训练方式为自由负重练习,每周2次,每次持续60 min,2次间歇≥48 h。实验前后分别测定心率、血压(收缩压和舒张压)、心率变异性(HRV)、血压变异性(BPV)和压力反射敏感性(BRS)。结果实验前,2组受试者各参数比较差异均无统计学意义(P值均>0.05)。实验后,组内比较,ST组舒张压[实验前(77±5)mmHg,实验后(72±4)mmHg]、BPV总功率(TP)[实验前(40.3±6.4)mmHg^2,实验后(32.8±5.5)mmHg^2]和BPV标准化低频功率(LFn)[实验前(28.6±3.7)%,实验后(19.4±3.9)%]降低(P值均<0.05),安静心率、收缩压、HRV各指标以及BRS的变化均无统计学意义(P值均>0.05);RC组所有指标差异无统计学意义(P值均>0.05)。实验后,组间比较,ST组舒张压[ST组(72±4)mm Hg,RC组(78±4)mm Hg]、BPV TP[ST组(32.8±5.5)mmHg^2,RC组(42.1±5.9)mmHg^2]和BPV LFn[ST组(19.4±3.9)%,RC组(25.2±5.5)%]低于RC组(P值均<0.05)。结论 8周力量训练能够显著改善肥胖男性青少年交感缩血管神经调节功能。     

锻炼行为阶段改变对肥胖青少年生活质量的影响

探讨肥胖青少年身体锻炼行为阶段改变对主观生活质量的影响,为肥胖青少年制定运动锻炼干预策略及提高生活质量提供参考.方法 采用分层整群随机抽样方法,筛选盐城市11~18岁中小学生中肥胖青少年268名,采用问卷调查的方式收集研究对象一般资料及所处的运动行为阶段,采用“儿童少年生活质量量表”评估健康相关生活质量.结果 肥胖青少年前意向阶段占33.96%,意向阶段25.00%,准备阶段21.27%,行动阶段15.67%,维持阶段4.10%.生活质量总分及生理、心理、社会因素、生活环境各维度得分分别为(141.53±6.24)、(32.03±2.42)、(43.52±2.46)、(45.27±2.54)、(18.62±2.26)分.单因素方差分析显示,生活质量生理、心理维度及总分在不同行为阶段间差异均有统计学意义(F值分别为145.408,134.542,113.163,P值均<0.05);秩和相关分析显示,生活质量生理、心理维度及生活质量总分与运动锻炼的阶段行为存在正相关(r值分别为0.663,0.654,0.704,P值均<0.05).结论 不同运动行为阶段肥胖青少年的生活质量总分及生理、心理维度得分差异有统计学意义,进行有规律的运动锻炼可明显改善肥胖青少年的生理、心理状态及生活质量.     

Acute effects of beer on endothelial function and hemodynamics: A single-blind,crossover study in healthy volunteers

ObjectiveModerate consumption of beer is associated with lower cardiovascular (CV) risk. The goal of this study was to determine the effect of beer consumption on CV risk. To explore the underlying mechanisms, we studied the acute effects of the constituents of beer (alcohol and antioxidants), on established predictors of CV risk: endothelial function, aortic stiffness, pressure wave reflections and aortic pressure.MethodsIn a randomized, single-blind, crossover study, 17 healthy, non-smoking, men (ages 28.5 ± 5.2 y with body mass index 24.4 ± 2.5 kg/m²) consumed on three separate occasions, at least 1 wk apart: 1. 400 mL of beer and 400 mL water, 2. 800 mL of dealcoholized beer (same amount of polyphenols as in the 400 mL of beer), and 3. 67 mL of vodka and 733 mL water (same amount of alcohol as in the 400 mL of beer).Each time aortic stiffness (pulse wave velocity), pressure wave reflections (AΙx), aortic and brachial pressure (Sphygmocor device), and endothelial function (brachial flow mediated dilatation) were assessed at fast and 1 and 2 h postprandial.ResultsAortic stiffness was significantly and similarly reduced by all three interventions. However, endothelial function was significantly improved only after beer consumption (average 1.33%, 95% confidence interval [CI] 0.15–2.53). Although wave reflections were significantly reduced by all three interventions (average of beer: 9.1%, dealcoholized beer: 2.8%, vodka 8.5%, all CI within limits of significance), the reduction was higher after beer consumption compared with dealcoholized beer (P = 0.018). Pulse pressure amplification (i.e., brachial/aortic) was increased by all three test drinks.ConclusionsBeer acutely improves parameters of arterial function and structure, in healthy non-smokers. This benefit seems to be mediated by the additive or synergistic effects of alcohol and antioxidants and merits further investigation.     

有氧运动综合干预措施对肥胖儿童血瘦素和血脂成分的影响

目的:观察有氧运动综合干预措施对单纯性肥胖儿童血瘦素及血脂成分的影响,为家长、教育系统建立有效可行的儿童肥胖干预措施提供科学依据。方法:单纯性肥胖儿童采取健康知识教育、有氧运动、合理饮食等疗法进行为期10个月的综合干预试验,测定干预前后身高、体重、腰围、臀围、血瘦素及血脂水平的变化。结果:经过10个月的综合干预活动,干预组肥胖儿童腰围、臀围、血瘦素、TG、LDL-C和apoB100较干预前明显降低(P<0.05),HDL-C、apoA-I较干预前明显升高(P<0.05);而对照组上述指标在干预前后无明显变化(P>0.05)。结论:综合干预措施能有效降低体重,改善肥胖儿童体内瘦素和血脂成分,起到调节异常内分泌代谢的作用。