Comparison of running performances and prevalence of overweight and obesity in Hungarian and Ukrainian adolescents

The 20-m shuttle run (20-mSRT) is a widely used field test to estimate peak oxygen consumption (VO2peak) and thus to assess aerobic fitness of adolescents (11). The purpose of this study was to analyse differences in basic anthropometric measurements (stature, body mass, percent body fat, BMI) and in aerobic fitness of Hungarian and Ukrainian adolescent boys and girls. We examined gender differences in maximal speed (km h-1), in peak VO2 (mL kg-1 min-1) and maximal heart rate (HRmax min-1). Two hundred ninety-two Ukrainian (mean age=16.5±0.5) and 374 (mean age=16.5±0.5) Hungarian adolescents volunteered to participate in this study. Differences were analysed using factorial analysis of the variance (ANOVA) and Student's t-test. Statistical significance was set at p<0.05. Hungarian boys and girls were significantly taller, heavier and had higher percent body fat than their Ukrainian counterparts. Altogether 10% of Hungarians and 7% of Ukrainians were classified overweight or obese according to Cole's BMI classification (4). VO2peak of Ukrainians (mean=49.44±5.29 mL kg-1 min-1) were significantly higher than that of Hungarians (mean=41.93±8.40 mL kg-1 min-1). Maximal heart rate also differed significantly (Ukrainians mean=201.12±8.43 min-1 vs. Hungarians mean=185.38±18.38 min-1).In conclusion, aerobic fitness of the Ukrainian adolescents was significantly higher than that of the Hungarians independently of BMI or gender.     

Effects of an 8-week aerobic exercise training on saliva steroid hormones, physical capacity, and quality of life in diabetic obese men

The purpose of the study was to assess the effects of aerobic exercise training on saliva steroid hormones [i.?e., cortisol, dehydroepiandrosterone (DHEA), and testosterone], physical capacity, and quality of life in obese diabetic men. 8 abdominally obese type 2 diabetic men (59.5±1.7 years old, BMI=35.5±1.6?kg/m(2), waist circumference=119.4±3.3?cm) and 9 healthy men (57.4±1.5 years old, BMI=24.5±0.8?kg/m(2), waist circumference=92.3±1.9?cm) participated in the study. The obese diabetic men underwent 8 weeks of aerobic exercise training: twice a week 45?min sessions at 75% of peak heart rate and once a week 45?min session of intermittent exercise. Before and after training, steroid hormone concentrations were analyzed from saliva samples, physical capacity was assessed by the 6-minute walking test, and quality of life was estimated by a specific questionnaire for obese subjects. These data were compared with the data from the healthy untrained men. The basal saliva DHEA and testosterone concentrations, physical capacity, and quality of life scores of the obese diabetic men were significantly lower than those of the healthy men. Aerobic training induces a significant increase in the 6-min walking distance and improve the psychosocial impact dimension of quality of life, without modifying significantly any other parameter investigated. These data suggest that an 8-week aerobic exercise program improves physical capacity and quality of life in obese diabetic men, but was insufficient to correct the anthropometric and hormonal alterations observed in this population.     

From metabolic normality to cardiometabolic risk factors in subjects with obesity

The aim of the study was to evaluate the 3 years incidence of cardiometabolic risk factors, such as impaired fasting glucose, reduced high-density lipoprotein (HDL)-cholesterol, increased plasma triglycerides or blood pressure as well as impaired glucose tolerance in overweight or obese (ow/ob) and normal body weight (nbw) subjects metabolically normal at baseline. Subjects from the Relationship between Insulin Sensitivity and Cardiovascular Disease (RISC) study were analyzed. We analyzed 284 nbw and 152 ow/ob subjects who, at baseline, did not show any of the above-mentioned cardiometabolic risk factors. At 3 years, these parameters were re-evaluated. Intima-media thickness (IMT) of the common carotid artery (CCA) was echographically measured. At follow-up, the incidence of one or more cardiometabolic risk factors was 57.2% in ow/ob vs. 31.7% in nbw (P < 0.0001). After adjustment for age, sex, menopause status, lifestyle parameters, insulin sensitivity, and fasting insulinemia, BMI remained significantly linked to the development of one or more cardiometabolic risk factors (P = 0.02). An increased BMI at follow-up was significantly associated with the development of cardiometabolic alterations, in both nbw and ow/ob groups (P = 0.04). Ow/ob subjects who, at 3 years follow-up, remained metabolically normal, showed a less favourable cardiometabolic profile, when compared to nbw counterparts. In ow/ob metabolically normal males and females, intima-media of the common carotid at follow-up was thicker than in nbw (P = 0.03 for males, P = 0.04 for females). In conclusion, metabolically normal obese subjects show a higher incidence of cardiometabolic risk factors, in a short follow-up period. Weight gain is significantly associated with the development of these factors, in both nbw and ow/ob subjects.     

Fatness, fitness, and insulin sensitivity among 7- to 9-year-old children

Objective: The purpose of this study was to examine the relationships among fatness and aerobic fitness on indices of insulin resistance and sensitivity in children. Research Design and Methods: A total of 375 children (193 girls and 182 boys) 7 to 9 years of age were categorized by weight as normal‐weight, overweight, or obese and by aerobic fitness based on a submaximal physical working capacity test (PWC). Fasting blood glucose (GLU) and insulin (INS) were used to calculate various indices of insulin sensitivity (GLU/INS), the homeostasis model assessment (HOMA), and the quantitative insulin sensitivity check index (QUICKI). Surrogate measures of pancreatic β cell function included the insulinogenic index (INS/GLU) and the HOMA estimate of pancreatic β‐cell function (HOMA %B). Results: Insulin sensitivity and secretion variables were significantly different between the normal‐weight children and the overweight and obese subjects. Fasting insulin (FI), HOMA, QUICKI, and INS/GLU were significantly different between the overweight and obese subjects. Likewise, the high fitness group possessed a better insulin sensitivity profile. In general, the normal‐weight–high fit group possessed the best insulin sensitivity profile and the obese‐unfit group possessed the worst insulin sensitivity profile. Several significant differences existed among the six fat‐fit groups. Of particular note are the differences within BMI groups by fitness level and the comparison of values between the normal‐weight–unfit subjects and the overweight and obese subjects with high fitness. Conclusions: The results indicate that aerobic fitness attenuates the difference in insulin sensitivity within BMI categories, thus emphasizing the role of fitness even among overweight and obese children.     

Maternal weight change between 1 and 2 years postpartum: the importance of 1 year weight retention

Pregnancy weight gain may lead to long-term increases in maternal BMI for some women. The objective of this study was to examine maternal body weight change 1y-2y postpartum, and to compare classifications of 2y weight retention with and without accounting for 1y-2y weight gain. Early pregnancy body weight (EPW, first trimester) was measured or imputed, and follow-up measures obtained before delivery, 1 year postpartum (1y) and 2 years postpartum (2y) in an observational cohort study of women seeking prenatal care in several counties in upstate New York (n = 413). Baseline height was measured; demographic and behavioral data were obtained from questionnaires and medical records. Associations of 1y-2y weight change (kg) and 1y-2y weight gain (≥2.25 kg) with anthropometric, socioeconomic, and behavioral variables were evaluated using linear and logistic regressions. While mean ± SE 1y-2y weight change was 0.009 ± 4.6 kg, 1y-2y weight gain (≥2.25 kg) was common (n = 108, 26%). Odds of weight gain 1y-2y were higher for overweight (OR(adj) = 2.63, CI(95%) = 1.43-4.82) and obese (OR(adj) = 2.93, CI(95%) = 1.62-5.27) women than for women with BMI <25. Two year weight retention (2y-EPW ≥2.25 kg) was misclassified in 38% (n = 37) of women when 1y-2y weight gain was ignored. One year weight retention (1YWR) (1y-EPW) was negatively related to 1y-2y weight change (β(adj) ± SE = -0.28 ± 0.04, P < 0.001) and weight gain (≥2.25 kg) (OR(adj) = 0.91, CI(95%) = 0.87-0.95). Relations between 1y weight retention and 1y-2y weight change were attenuated for women with higher early pregnancy BMI. Weight change 1y-2y was predicted primarily by an inverse relation with 1y weight retention. The high frequency of weight gain has important implications for classification of postpartum weight retention.     

Diastolic dysfunction and intraventricular dyssynchrony are restored by low intensity exercise training in obese men

The aim of this study was to evaluate the impact of a low-intensity training program on subclinical cardiac dysfunction and on dyssynchrony in moderately obese middle aged men. Ten obese and 14 age-matched normal-weight men (BMI: 33.6 ± 1.0 and 24.2 ± 0.5 kg/m(2)) were included. Obese men participated in an 8-week low-intensity training program without concomitant diet. Cardiac function and myocardial synchrony were assessed by echocardiography with tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE). At baseline, obese men showed diastolic dysfunction on standard echocardiography, lower strain values (systolic strain: 15.9 ± 0.9 vs. 18.8 ± 0.3%, diastolic strain rate: 0.81 ± 0.09 vs. 1.05 ± 0.06 s(-1)), and significant intraventricular dyssynchrony (systolic: 13.3 ± 2.1 vs. 5.4 ± 2.1 ms, diastolic: 17.4 ± 3.2 vs. 9.1 ± 2.1 ms) (P < 0.05 vs. controls for all variables). Training improved aerobic fitness, decreased systolic blood pressure and heart rate, and reduced fat mass without weight loss. Diastolic function, strain values (systolic strain: 17.4 ± 0.9%, diastolic strain rate: 0.96 ± 0.12 s(-1)) and intraventricular dyssynchrony (systolic: 3.3 ± 1.7 ms, diastolic: 5.5 ± 3.4 ms) improved significantly after training (P < 0.05 vs. baseline values for all variables), reaching levels similar to those of normal-weight men. In conclusion, in obese men, a short and easy-to-perform low intensity training program restored diastolic function and cardiac synchrony and improved body composition without weight loss.     

Effects of body mass index on maximal work production capacity and aerobic fitness during incremental exercise

The aim of this study was to investigate the relationship between cardiopulmonary fitness as indicated by maximal work rate (Wmax) production and aerobic capacities (WAT), body mass index (BMI) and heart rate reserve. A total of 60 sedentary subjects (30 males, 30 females, aged 18-25 years) were enrolled in the study. Each subject performed an incremental exercise test (15 W/min) to the limit of tolerance on an electromagnetically-braked cycle ergometer. There was a negative correlation between increased BMI to Wmax capacity per kilogram body weight in male (r=-0.846, P=0.0001) and in female (r=-0.896, P=0.0001) subjects. In addition, W(AT) for each kilogram body weight also negatively correlated with increased BMI in male (r=-0.870, P=0.0001) and in females (r=-0.807, P=0.0001). The heart rate reserve correlated negatively with increasing BMI: r=-0.699, P=0.0001 (males) and r=-0.655, P=0.0001 (females). The results of the present study have suggested that, due to the inverse correlation between BMI, Wmax capacity, aerobic fitness and heart rate reserve, it may be useful to consider BMI in establishing cardiopulmonary fitness in various subjects.     

Weight loss and sleep-disordered breathing in childhood obesity: effects on inflammation and uric acid

Sleep-disordered breathing (SDB) is prevalent in childhood obesity. It may be an independent risk factor for the metabolic syndrome. Possible mechanisms are inflammation and oxidative stress. Adenotonsillectomy in childhood obesity is associated with a high recurrence rate and risk of postoperative weight gain. Therefore, this study assessed the effects of SDB on inflammation and oxidative stress in childhood obesity before and after weight loss. We included 132 obese subjects between 10 and 18 years consecutively. Median age was 15.4 years (10.1-18.0). Mean BMI z-score was 2.72 ± 0.42. Leukocytes and differentiation, high sensitivity C-reactive protein (hs-CRP), and uric acid (UA) were determined at baseline and subjects underwent a sleep assessment. SDB was diagnosed in 39%. Linear regression analysis showed an association between UA(log) and oxygen desaturation index(log) (ODI(log)) (r = 0.20; P = 0.03), between leukocytes(log) and respiratory disturbance index(log) (RDI(log)) (r = 0.23; P = 0.01), and between lymphocytes(log) and RDI(log) (r = 0.19; P = 0.04). Follow-up was organized after 4-6 months of treatment. Median decrease in BMI z-score was 32%. Laboratory measurements were repeated. Subjects with SDB at baseline underwent a second sleep study. Of these 49 subjects, 12 showed residual SDB. This corresponds with a treatment success rate of 71%. Unlike changes in inflammatory markers, improvements in UA were associated with improvements in RDI and ODI (respectively: r = 0.44; P = 0.007, r = 0.41; P = 0.01). In conclusion, weight loss is effective in treating obese children with SDB. At baseline, a link exists between inflammation and SDB. Oxidative stress is reflected by UA at baseline and the concentration decreases after treatment according to improvements in SDB.     

Modulation of extracellular matrix genes reflects the magnitude of physiological adaptation to aerobic exercise training in humans

Background  

Regular exercise reduces cardiovascular and metabolic disease partly through improved aerobic fitness. The determinants of exercise-induced gains in aerobic fitness in humans are not known. We have demonstrated that over 500 genes are activated in response to endurance-exercise training, including modulation of muscle extracellular matrix (ECM) genes. Real-time quantitative PCR, which is essential for the characterization of lower abundance genes, was used to examine 15 ECM genes potentially relevant for endurance-exercise adaptation. Twenty-four sedentary male subjects undertook six weeks of high-intensity aerobic cycle training with muscle biopsies being obtained both before and 24 h after training. Subjects were ranked based on improvement in aerobic fitness, and two cohorts were formed (n = 8 per group): the high-responder group (HRG; peak rate of oxygen consumption increased by +0.71 ± 0.1 L min^-1; p < 0.0001) while the low-responder group (LRG; peak rate of oxygen consumption did not change, +0.17 ± 0.1 L min^-1, ns). ECM genes profiled included the angiopoietin 1 and related genes (angiopoietin 2, tyrosine kinase with immunoglobulin-like and EGF-like domains 1 (TIE1) and 2 (TIE2), vascular endothelial growth factor (VEGF) and related receptors (VEGF receptor 1, VEGF receptor 2 and neuropilin-1), thrombospondin-4, α2-macroglobulin and transforming growth factor β2.     

Physical Training Improves Body Composition of Black Obese 7- to 11-Year-Old Girls

We determined the effect of supervised physical training, without dietary intervention, on body composition of obese girls. The subjects were 25 obese 7-to 11-year-old black girls, divided into physical training and lifestyle education groups which were comparable on baseline body composition; 22 girls finished all aspects of the study. Twelve girls engaged in aerobic training (10 weeks, 5 days/week) while 10 engaged in weekly lifestyle discussions without formal physical training. Total body and regional body composition were measured with dual energy x-ray absorptiometry, skin folds and circumferences. Aerobic fitness was measured by heart rate response to sub maximal treadmill exercise. The physical training group attended 94% of scheduled sessions and kept their heart rates at an average of 163 bpm for 28 minutes/session. The lifestyle group attended 95% of their sessions; they remained stable in aerobic fitness and most body composition measurements. The physical training group showed a significant improvement in aerobic fitness and a significant decline of 1.4% body fat. Skin fold and circumference indices of fatness also declined significantly in physical training, without dietary intervention, improved the fitness and body composition of obese black girls.     

Does fitness level modulate the cardiovascular hemodynamic response to exercise?

Subjects with greater aerobic fitness demonstrate better diastolic compliance at rest, but whether fitness modulates exercise cardiac compliance and cardiac filling pressures remains to be determined. On the basis of maximal oxygen consumption (VO2max), healthy male subjects were categorized into either low (LO: VO2max=43+/-6 ml.kg-1.min-1; n=3) or high (HI: VO2max=60+/-3 ml.kg-1.min-1; n=5) aerobic power. Subjects performed incremental cycle exercise to 90% Vo(2max). Right atrial (RAP) and pulmonary artery wedge (PAWP) pressures were measured, and left ventricular (LV) transmural filling pressure (TMFP=PAWP-RAP) was calculated. Cardiac output (CO) and stroke volume (SV) were determined by direct Fick, and LV end-diastolic volume (EDV) was estimated from echocardiographic fractional area change and Fick SV. There were no between-group differences for any measure at rest. At a submaximal workload of 150 W, PAWP and TMFP were higher (P<0.05) in LO compared with HI (12 vs. 8 mmHg, and 9 vs. 4 mmHg, respectively). At peak exercise, CO, SV, and EDV were lower in LO (P<0.05). RAP was not different at peak exercise, but PAWP (23 vs. 15 mmHg) and TMFP (12 vs. 6 mmHg) were higher in LO (P<0.05). Compared with less fit subjects, subjects with greater aerobic fitness demonstrated lower LV filling pressures during exercise, whereas SV and EDV were either similar (submaximal exercise) or higher (peak exercise), suggesting superior diastolic function and compliance.     

Effects of aerobic exercise on metabolic syndrome improvement in response to weight reduction

Objective: The objective was to test effects of aerobic exercise training on metabolic syndrome (MetSyn) improvement in response to weight reduction. Research Methods and Procedures: A total of 459 overweight and obese women (age, 49 ± 9 years; BMI, 28 ± 3 kg/m²) were recruited for a baseline examination to test the relationship between cardiorespiratory fitness and metabolic syndrome prevalence; among these, 67 subjects with MetSyn were treated with 14‐week weight‐loss programs, which included low‐calorie diet and aerobic exercise. The MetSyn was defined according to the Examination Committee of Criteria for “Metabolic Syndrome” in Japan. Maximal oxygen uptake (V?o _2max) during a maximal cycling test was measured as an index of cardiorespiratory fitness at baseline and after the intervention. Results: In the baseline examination, age‐ and BMI‐adjusted odds ratios for MetSyn prevalence in the low, middle, and upper thirds of V?o _2max were 1.0 (referent), 0.50 (95% confidence interval, 0.26 to 0.95), and 0.39 (95% confidence interval, 0.14 to 0.96), respectively (linear trend, p = 0.02). The adjusted odds ratios for MetSyn improvement in the two interventions with diet alone and diet plus exercise were 1.0 and 3.68 (95% confidence interval, 1.02 to 17.6; p = 0.04), respectively. Discussion: These results suggest that adding aerobic exercise training to a dietary weight‐reduction program further improves MetSyn (adjusted odds ratio, 3.68) in obese women, compared with diet alone. Further studies on an association between V?o _2max change and MetSyn improvement are needed.     

A 6-month supervised employer-based minimal exercise program for police officers improves fitness

The purpose of the study was to determine the effects of a 6-month supervised, job-specific moderate exercise program in police officers on body composition, cardiovascular and muscular fitness. Body weight (BW), body mass index (BMI), and cardiovascular and muscular fitness were assessed at baseline, after a 6-month supervised fitness program and at 12-month follow-up (18 months). One hundred sixty-five (n = 131 men and n = 34 women) young (mean ± SEM, 26.4 ± 1.9 years), overweight (BMI = 26.2 ± 1.2 kg·m) police officers participated. Aerobic exercise progressed from 3 d·wk, 20 minutes per session at 60% of the heart rate reserve (HRR) to 5 d·wk, 30 minutes per session at 75% of HRR at 3 months, and this level was maintained until 6 months. Muscular strength training progressed using 8 different calisthenics exercises from 3 d·wk, 2 sets of 5 repetitions using the participant's own BW to 5 d·wk, 3 sets of 15 repetitions of the participant's own BW at 3 months, and this level was maintained until 6 months. Cardiovascular and muscular fitness was measured using a 0.25-mile obstacle course incorporating various job-specific exercises and expressed as the physical abilities test (PAT) time. There was a significant reduction in BMI (-0.6 ± 0.2 kg·m, p < 0.001) and BW (-2.8 ± 2.3 kg) and reduction in PAT time (-11.9 ± 2.1%, p < 0.01) from baseline to 6 months. However, BMI (1.4 ± 1.1 kg·m, p < 0.001), BW (5.1 ± 3.0 kg, p < 0.01), and PAT time significantly increased (12.8 ± 2.2%, p < 0.01) from 6 to 18 months. There were no sex by time differences. The practical applications of this study indicate that a supervised, job-specific exercise program for police officers improves fitness and body composition after 6 months in both men and women, but continued supervision of exercise program may be necessary for maintenance of health benefits.     

Body adiposity and type 2 diabetes: increased risk with a high body fat percentage even having a normal BMI

Obesity is the major risk factor for the development of prediabetes and type 2 diabetes. BMI is widely used as a surrogate measure of obesity, but underestimates the prevalence of obesity, defined as an excess of body fat. We assessed the presence of impaired glucose tolerance or impaired fasting glucose (both considered together as prediabetes) or type 2 diabetes in relation to the criteria used for the diagnosis of obesity using BMI as compared to body fat percentage (BF%). We performed a cross-sectional study including 4,828 (587 lean, 1,320 overweight, and 2,921 obese classified according to BMI) white subjects (66% females), aged 18-80 years. BMI, BF% determined by air-displacement plethysmography (ADP) and conventional blood markers of glucose metabolism and lipid profile were measured. We found a higher than expected number of subjects with prediabetes or type 2 diabetes in the obese category according to BF% when the sample was globally analyzed (P < 0.0001) and in the lean BMI-classified subjects (P < 0.0001), but not in the overweight or obese-classified individuals. Importantly, BF% was significantly higher in lean (by BMI) women with prediabetes or type 2 diabetes as compared to those with normoglycemia (NG) (35.5 ± 7.0 vs. 30.3 ± 7.7%, P < 0.0001), whereas no differences were observed for BMI. Similarly, increased BF% was found in lean BMI-classified men with prediabetes or type 2 diabetes (25.2 ± 9.0 vs. 19.9 ± 8.0%, P = 0.008), exhibiting no differences in BMI or waist circumference. In conclusion, assessing BF% may help to diagnose disturbed glucose tolerance beyond information provided by BMI and waist circumference in particular in male subjects with BMI <25 kg/m(2) and over the age of 40.     

Oxidation of nonplasma fatty acids during exercise is increased in women with abdominal obesity.

We evaluated plasma fatty acid availability and plasma and whole body fatty acid oxidation during exercise in five lean and five abdominally obese women (body mass index = 21 +/- 1 vs. 38 +/- 1 kg/m(2)), who were matched on aerobic fitness, to test the hypothesis that obesity alters the relative contribution of plasma and nonplasma fatty acids to total energy production during exercise. Subjects exercised on a recumbent cycle ergometer for 90 min at 54% of their peak oxygen consumption. Stable isotope tracer methods ([(13)C]palmitate) were used to measure fatty acid rate of appearance in plasma and the rate of plasma fatty acid oxidation, and indirect calorimetry was used to measure whole body substrate oxidation. During exercise, palmitate rate of appearance increased progressively and was similar in obese and lean groups between 60 and 90 min of exercise [3.9 +/- 0.4 vs. 4.0 +/- 0.3 micromol. kg fat free mass (FFM)(-1). min(-1)]. The rate of plasma fatty acid oxidation was also similar in obese and lean subjects (12.8 +/- 1.7 vs. 14.5 +/- 1.8 micromol. kg FFM(-1). min(-1); P = not significant). However, whole body fatty acid oxidation during exercise was 25% greater in obese than in lean subjects (21.9 +/- 1.2 vs. 17.5 +/- 1.6 micromol. kg FFM(-1). min(-1); P < 0.05). These results demonstrate that, although plasma fatty acid availability and oxidation are similar during exercise in lean and obese women, women with abdominal obesity use more fat as a fuel by oxidizing more nonplasma fatty acids.     

Skinfold thickness is related to cardiovascular autonomic control as assessed by heart rate variability and heart rate recovery

The purpose of this study was to determine if heart rate recovery (HRR) and heart rate variability (HRV) are related to maximal aerobic fitness and selected body composition measurements. Fifty men (age = 21.9 ± 3.0 years, height = 180.8 ± 7.2 cm, weight = 80.4 ± 9.1 kg, volunteered to participate in this study. For each subject, body mass index (BMI), waist circumference (WC), and the sum of skinfolds across the chest, abdomen, and thigh regions (SUMSF) were recorded. Heart rate variability (HRV) was assessed during a 5-minute period while the subjects rested in a supine position. The following frequency domain parameters of HRV were recorded: normalized high-frequency power (HFnu), and low-frequency to high-frequency power ratio (LF:HF). To determine maximal aerobic fitness (i.e., VO2max), each subject performed a maximal graded exercise test on a treadmill. Heart rate recovery was recorded 1 (HRR1) and 2 (HRR2) minutes during a cool-down period. Mean VO2max and BMI for all the subjects were 49.5 ± 7.5 ml·kg(-1)·min(-1) and 24.7 ± 2.2 kg·m(-2), respectively. Although VO2max, WC, and SUMSF was each significantly correlated to HRR and HRV, only SUMSF had a significant independent correlation to HRR1, HRR2, HFnu, LF:HF (p < 0.01). The results of the regression procedure showed that SUMSF accounted for the greatest variance in HRR1, HRR2, HFnu, and LF:HF (p < 0.01). The results of this study suggest that cardiovascular autonomic modulation is significantly related to maximal aerobic fitness and body composition. However, SUMSF appears to have the strongest independent relationship with HRR and HRV, compared to other body composition parameters and VO2max.     

Lower than predicted resting metabolic rate is associated with severely impaired cardiorespiratory fitness in obese individuals

Obese individuals have reduced cardiorespiratory fitness as compared with leaner counterparts. Regular exercise maintains or increases fitness and lean body mass. Lean body mass, in turn, has a direct impact on resting metabolic rate (RMR). Given these relationships, we sought to evaluate the association between RMR and cardiorespiratory fitness in obese individuals. We evaluated 64 obese individuals (78% female) with direct assessment of RMR and cardiorespiratory fitness via breath‐by‐breath measurement of oxygen consumption and carbon dioxide production at rest and during exercise. The mean age and BMI were 47.4 ± 12.2 years and 47.2 ± 9.2 kg/m², respectively. The majority of subjects, 69%, had a measured RMR above that predicted by the Harris‐Benedict equation. Compared with the higher RMR group, those with a lower than predicted RMR had increased BMI, with values of 52.9 vs. 44.7 kg/m², P = 0.001, respectively. Analysis of those demonstrating significant effort during cardiopulmonary exercise testing (peak respiratory exchange ratio ≥1.10) revealed a significantly higher peak oxygen uptake (VO₂ peak) in the higher RMR group (17.3 ± 3.5 ml/min/kg) compared with the lower RMR group (13.6 ± 1.9 ml/min/kg), P = 0.003. In summary, a lower than predicted RMR was associated with a severely reduced VO₂ peak and a higher BMI in this cohort. These data suggest that morbid obesity may be a vicious cycle of increasing BMI, reduced cardiorespiratory fitness, muscle deconditioning, and lower RMR. Collectively, these responses may, over time, exacerbate the imbalance between energy intake and expenditure, resulting in progressive increases in body weight and fat stores.     

Proficiency deficiency: mastery of fundamental movement skills and skill components in overweight and obese children

The purpose of this observational study was to compare the mastery of 12 fundamental movement skills (FMS) and skill components between a treatment-seeking sample of overweight/obese children and a reference sample from the United States. Mastery of six locomotor and six object-control skills (24 components in each subdomain) were video-assessed by one assessor using the test of gross motor development-2 (TGMD-2). The 153 overweight/obese children (mean ± s.d. age = 8.3 ± 1.1 years, BMI z-score = 2.78 ± 0.69, 58% girls, 77% obese) were categorized into age groups (for the underhand roll and strike: 7-8 years and 9-10 years; all other FMS: 6-7 years and 8-10 years) and mastery prevalence rates were compared with representative US data (N = 876) using χ(2) analysis. For all 12 skills in all age groups, the prevalence of mastery was lower among overweight/obese children compared with the reference sample (all P < 0.05). This was consistent for 18 locomotor and upto 21 object-control skill components (all P < 0.05). Differences were largest for the run, slide, hop, dribble, and kick. Specific movement patterns that could be targeted for improvement include positioning of the body and feet, the control or release of an object at an optimal position, and better use of the arms to maintain effective force production during the performance of FMS. Physical activity programs designed for overweight and obese children may need to address deficiencies in FMS proficiency to foster the movement capabilities required for participation in health-enhancing physical activity.     

Association of the FTO gene with BMI

Variants in the FTO gene have been strongly associated with obesity in a very large sample (38,759) of diabetic and control subjects. To replicate these findings, the previously reported SNP in the FTO gene (rs9939609, T/A) was genotyped in 5,607 subjects from five different Utah studies. The studies included a random sample of the Utah population, families selected for aggregation of extreme thinness, families selected for severe obesity, a series of unrelated severe obesity subjects, and families participating in a 25-year longitudinal study of cardiovascular disease and aging. Results show a strong significant increase in the rs9939609 A allele frequency with increasing BMI (P < 0.0001). In the longitudinal study, FTO genotypes were significantly associated with BMI at a baseline exam, a 2(1/2)-year follow-up exam and a 25-year follow-up exam using an additive genetic model. The mean genotype difference in BMI ranged from 1.3 to 2.1 kg/m(2) across exams. The genotype difference in BMI means was established in youth, and at-risk subjects under age 20 at baseline had a significantly larger 25-year BMI increase (10.0 for A/A; 9.7 for A/T, and 8.5 kg/m(2) for T/T, P = 0.05). We conclude that the BMI increases associated with FTO genotypes begin in youth and are maintained throughout adulthood.