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.

High-intensity activity is an important aspect of football performance during competitive match play. The aim of this study was to investigate the effect of beta-alanine supplementation throughout a short-duration intense football-specific training period prior to an international competition on measures of high-intensity running performance. Methods: Twenty-four elite international U20 female footballers (age 18 ± 1 y, height 1.67 ± 0.07 m, body mass 62.7 ± 7.4 kg) volunteered to perform the YoYo Intermittent Recovery Test Level 1 (YoYo IR1), the Running Anaerobic Sprint Test (RAST) and a 20-m maximal sprint test on two separate occasions, separated by 3 weeks of training and supplementation. Participants were randomly assigned to receive either 6.4 g•day −1 sustained-release beta-alanine (BA, N = 12) or an equivalent dose of maltodextrin (placebo, PL, N = 12) throughout a 3-week standardized training camp. Results: There was a main effect of group (P = 0.05) and time (P = 0.004) on YoYo IR1; overall values were lower in PL and distance covered was lower post-vs. presupplementation. There was no group × time interaction (P = 0.07). There was an effect of sprint number for RAST, but no further main effects and there were no effect for the 20-m sprint. Conclusions: Top-level female footballers involved in this intense 3-week training period prior to a competition worsened their high-intensity intermittent exercise capacity, and this negative result was not attenuated by a short-duration BA supplementation protocol throughout the same period. Further work is necessary to elucidate whether adapted training protocols and BA dosing regimens could lead to better results.

No relationships reported)Assessing physical activity (PA) in adults and children is difficult, and the use of accelerometers is currently the most common method based on validity and reliability. However, the use of accelerometry is not practical in large samples. PURPOSE:To determine whether a simplified daily PA questionnaire can be used in adolescents to accurately assess activity levels when compared to accelerometry data. METHODS:Twenty-seven males and females aged 11-12 wore GT1M Actigraph accelerometers over seven days. A 10 second epoch was used to analyze accelerometry data during all waking hours. Each child was required to log the type and duration of physical activity each day based on moderate versus vigorous activity. Moderate PA was defined by 3-5.9 METS and vigorous PA as ≥6 METS. In regards to the daily diary, if an individual responded yes to sweating or breathing hard during activity it was considered vigorous. All other activities were considered of moderate intensity if the individual responded "no" to sweating or breathing hard. RESULTS:There was no significant association (r=0.217, p>.05) between the average time spent in combined moderate and vigorous activity assessed using accelerometry (38.4±20.9 minutes) and reported daily diary time (91.0±53.5 minutes). When examining each sex using accelerometry, males (46.9±22.9 minutes) exhibited a trend of higher activity levels when compared to females (31.1±16.1 minutes). CONCLUSION:Adolescents overestimated physical activity in both intensity and duration when using a daily diary questionnaire. Using this specific daily diary to assess physical activity levels in this population appears to be invalid and misleading. The present data indicates there is still a need for a survey that is valid to estimate PA in children and adolescents. Currently, the use of accelerometers is still the most appropriate and practical instrument to asses PA levels.Childhood obesity throughout the United States continues to rise. As a result, physical education (PE) class may help youth increase fitness, or prevent decreases in fitness as students progress. PURPOSE:The purpose of this study was to examine the percentages of students that met FITNESSGRAM Healthy Fitness Zone (HFZ) standards for body composition and aerobic conditioning in a large sample of elementary, middle, and high school physical education classes. METHODS:This study included 4,189 students (age 9-18 years) enrolled in physical education classes. PE teachers conducted fitness testing using FITNESSGRAM standards for body composition and aerobic conditioning. Youth were categorized into Meeting/Not Meeting current HFZ standards. The resulting distributions were created separately by age. RESULTS:Between age groups, the percentage of students meeting the HFZ standards ranged from 59% in 17-18 year olds to 85% in 9-10 year olds for the one mile run and 30% in 17-18 year olds to 84% in 9-10 year olds for PACER. The percentages of students meeting the HFZ for percent body fat ranged from 79% to 86% and...

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