PurposeTo compare two modalities of exercise training (i.e., Endurance Training [ET] and High-Intensity Interval Training [HIT]) on health-related parameters in obese children aged between 8 and 12 years.MethodsThirty obese children were randomly allocated into either the ET or HIT group. The ET group performed a 30 to 60-minute continuous exercise at 80% of the peak heart rate (HR). The HIT group training performed 3 to 6 sets of 60-s sprint at 100% of the peak velocity interspersed by a 3-min active recovery period at 50% of the exercise velocity. HIT sessions last ∼70% less than ET sessions. At baseline and after 12 weeks of intervention, aerobic fitness, body composition and metabolic parameters were assessed.ResultsBoth the absolute (ET: 26.0%; HIT: 19.0%) and the relative VO2 peak (ET: 13.1%; HIT: 14.6%) were significantly increased in both groups after the intervention. Additionally, the total time of exercise (ET: 19.5%; HIT: 16.4%) and the peak velocity during the maximal graded cardiorespiratory test (ET: 16.9%; HIT: 13.4%) were significantly improved across interventions. Insulinemia (ET: 29.4%; HIT: 30.5%) and HOMA-index (ET: 42.8%; HIT: 37.0%) were significantly lower for both groups at POST when compared to PRE. Body mass was significantly reduced in the HIT (2.6%), but not in the ET group (1.2%). A significant reduction in BMI was observed for both groups after the intervention (ET: 3.0%; HIT: 5.0%). The responsiveness analysis revealed a very similar pattern of the most responsive variables among groups.ConclusionHIT and ET were equally effective in improving important health related parameters in obese youth.

Background-The effects of diet and diet plus exercise training on muscle vasodilatation during physiological maneuvers in obese children are unknown. We tested the hypothesis that (1) blood pressure (BP) and forearm vascular conductance (FVC) responses during handgrip exercise and mental stress would be altered in obese children and (2) diet plus exercise training would restore BP and FVC responses during exercise and mental stress in obese children. Methods and Results-Thirty-nine obese children (aged 10Ϯ0.2 years) were randomly divided into 2 groups: diet plus exercise training (nϭ21; body mass index [BMI]ϭ28Ϯ0.5 kg/m 2 ) and diet (nϭ18; BMIϭ30Ϯ0.4 kg/m 2 ). Ten age-matched lean control children (BMIϭ17Ϯ0.5 kg/m 2 ) were also studied. Forearm blood flow was measured by venous occlusion plethysmography. BP was monitored noninvasively. Handgrip exercise was performed at 30% maximal voluntary contraction for 3 minutes. Stroop color word test was performed for 4 minutes. Baseline BP was significantly higher and FVC was significantly lower in obese children. During exercise and mental stress, BP responses were significantly higher and FVC responses were significantly lower in obese children. Diet and diet plus exercise training significantly reduced body weight. Diet and diet plus exercise training significantly decreased BP levels during exercise and mental stress. Diet plus exercise training, in contrast to diet alone, significantly increased FVC responses during exercise

We studied the effects of a hypocaloric diet (D, n = 24, age: 32.2 +/- 1.4 yr, body mass index: 34.7 +/- 0.5 kg/m2) and a hypocaloric diet associated with exercise training (D + T, n = 25, age: 32.3 +/- 1.3 yr, body mass index: 32.9 +/- 0.4 kg/m2) on muscle metaboreflex control, muscle sympathetic nerve activity (MSNA, microneurography), blood pressure, and forearm blood flow (plethysmography) levels during handgrip exercise at 10% and 30% of maximal voluntary contraction in normotensive obese women. An additional 10 women matched by age and body mass index were studied as a nonadherent group. D or D + T significantly decreased body mass index. D or D + T significantly decreased resting MSNA (bursts/100 heartbeats). The absolute levels of MSNA were significantly lower throughout 10% and 30% exercise after D or D + T, although no change was found in the magnitude of response of MSNA. D + T, but not D, significantly increased resting forearm vascular conductance. D + T significantly increased the magnitude of the response of forearm vascular conductance during 30% exercise. D or D + T significantly increased MSNA levels during posthandgrip circulatory arrest when muscle metaboreflex is isolated. In conclusion, weight loss improves muscle metaboreflex control in obese women. Weight loss reduces MSNA, which seems to be centrally mediated. Weight loss by D + T increases forearm vascular conductance at rest and during exercise in obese individuals.

Our data confirm that severe obesity is associated with increased TSH. The decrease in TSH was independent of BMI, but occurred in all SH patients. A putative effect of weight reduction on the improvement of SH in all patients may be an additional benefit of bariatric surgery.

The present data suggest that obesity has a negative impact on osteoarticular health by promoting biomechanical changes in the lumbar spine and lower extremities.

There is no information about the muscle metaboreflex control in obese individuals. In 40 normotensive obese women (OW; body mass index 33.5 +/- 0.4 kg/m2, age 32.4 +/- 1.1 yr) and 15 age-matched, normotensive lean women (LW; body mass index 22.7 +/- 0.8 kg/m2, age 34.4 +/- 1.4 yr), we measured muscle sympathetic nerve activity (MSNA) and forearm blood flow (FBF) in the nonexercising forearm during static exercise at 10 and 30% of maximal voluntary contraction (MVC). Baseline MSNA (38 +/- 2 vs. 31 +/- 1 bursts/min, P = 0.001) and mean blood pressure were significantly higher in OW compared with LW. FBF was significantly lower, whereas forearm vascular resistance was significantly higher in OW. During 10% MVC, MSNA increased similarly in both groups, but during 30% MVC, MSNA was higher in LW. FBF and forearm vascular resistance responses during both 10 and 30% MVC were similar between groups. During posthandgrip circulatory arrest, MSNA remained significantly elevated compared with baseline in both groups, but this increase was significantly lower in OW (3.8 +/- 0.82 vs. 9.4 +/- 1.03 bursts/min, P = 0.002). In conclusion, muscle metaboreflex control of MSNA is blunted in OW. MSNA responses are not augmented during selective activation of central command/mechanoreceptors and metaboreceptors, despite increased MSNA levels in OW. Muscle vasodilatory response during graded handgrip isometric exercise is preserved in OW.

The purpose of this study was to test the hypothesis that in obese children: 1) Ventilatory efficiency (VentE) is decreased during graded exercise; and 2) Weight loss through diet alone (D) improves VentE, and 3) diet associated with exercise training (DET) leads to greater improvement in VentE than by D. Thirty-eight obese children (10+/-0.2 years; BMI >95th percentile) were randomly divided into two study groups: D (n=17; BMI=30+/-1 kg/m (2)) and DET (n=21; 28+/-1 kg/m (2)). Ten lean children were included in a control group (10+/-0.3 years; 17+/-0.5 kg/m (2)). All children performed maximal treadmill testing with respiratory gas analysis (breath-by-breath) to determine the ventilatory anaerobic threshold (VAT) and peak oxygen consumption (VO (2) peak). VentE was determined by the VE/VCO (2) method at VAT. Obese children showed lower VO (2) peak and lower VentE than controls (p<0.05). After interventions, all obese children reduced body weight (p<0.05). D group did not improve in terms of VO (2) peak or VentE (p>0.05). In contrast, the DET group showed increased VO (2) peak (p=0.01) and improved VentE (DeltaVE/VCO (2)=-6.1+/-0.9; p=0.01). VentE is decreased in obese children, where weight loss by means of DET, but not D alone, improves VentE and cardiorespiratory fitness during graded exercise.

The purpose of this study was to test the hypotheses that in obese children: 1) hypocaloric diet (D) improves both heart rate recovery at 1 min (Δ HRR1) cfter an exercise test, and cardiac autonomic nervous system activity (CANSA) in obese children; 2) Diet and exercise training (DET) combined leads to greater improvement in both Δ HRR1 after an exercise test and in CANSA, than D alone. Moreover, we examined the relationships among Δ HRR1, CANSA, cardiorespiratory fitness and anthropometric variables (AV) in obese children submitted to D and to DET. 33 obese children (10 ± 0.2 years; body mass index (BMI) >95 (th) percentile) were divided into 2 groups: D (n=15; BMI=31 ± 1 kg/m²)) and DET (n=18; 29 ± 1 kg/m²). All children performed a maximal cardiopulmonary exercise test on a treadmill. The Δ HRR1 or LF/HF ratio (P>0.05). In contrast, the DET group showed increased peak VO₂ ( P=0.01) and improved Δ HRR1 (Δ HRR1=37.3 ± 2.6; P=0.01) and LF/HF ratio ( P=0.001). The DET group demonstrated significant relationships among Δ HRR1, peak VO₂ and CANSA (P<0.05). In conclusion, DET, in contrast to D, promoted improved ÄΔ HRR1 and CANSA in obese children, suggesting a positive influence of increased levels of cardiorespiratory fitness by exercise training on cardiac autonomic activity.