School recess provides a major opportunity to increase children's physical activity levels. Various studies have described strategies to increase levels of physical activity. The purpose of this systematic review is therefore to examine the interventions proposed as forms of increasing children's physical activity levels during recess. A systematic search of seven databases was made from the July 1 to July 5, 2012, leading to a final set of eight studies (a total of 2,383 subjects-599 "preschoolers" and 1,784 "schoolchildren") meeting the inclusion criteria. These studies were classified according to the intervention used: playground markings, game equipment, playground markings plus physical structures, and playground markings plus game equipment. The results of these studies indicate that the strategies analyzed do have the potential to increase physical activity levels during recess. The cumulative evidence was (a) that interventions based on playground markings, game equipment, or a combination of the two, do not seem to increase the physical activity of preschoolers and schoolchildren during recess and (ii) that interventions based on playground markings plus physical structures do increase the physical activity of schoolchildren during recess in the short to medium term.

No abstract

The aims of this study were (1) to compare water polo game-related statistics by context (winning and losing teams) and sex (men and women), and (2) to identify characteristics discriminating the performances for each sex. The game-related statistics of the 64 matches (44 men's and 20 women's) played in the final phase of the Olympic Games held in Beijing in 2008 were analysed. Unpaired t-tests compared winners and losers and men and women, and confidence intervals and effect sizes of the differences were calculated. The results were subjected to a discriminant analysis to identify the differentiating game-related statistics of the winning and losing teams. The results showed the differences between winning and losing men's teams to be in both defence and offence, whereas in women's teams they were only in offence. In men's games, passing (assists), aggressive play (exclusions), centre position effectiveness (centre shots), and goalkeeper defence (goalkeeper-blocked 5-m shots) predominated, whereas in women's games the play was more dynamic (possessions). The variable that most discriminated performance in men was goalkeeper-blocked shots, and in women shooting effectiveness (shots). These results should help coaches when planning training and competition.

This study develops multivariate models to predict swimming performance based on multidimensional assessment. 66 male (age 13.6 ± 0.6 y) and 67 female (11.5 ± 0.6 y) swimmers undertook a test battery including a sports background and training questionnaire, anthropometry, general and specific fitness tests, and technique. Competitive performance (LEN scores in three best events) was the predicted variable. A multiple linear regression model explained 82.4% of performance variability in males (based on age, sitting height, 30-min test, 6 × 50 m at 1:30, and swimming index) and 84.5% in females (age, 30-min test, 6 × 50 m at 1:30, and velocity at 50 m). Discriminant analysis using a four-group split-sample approach correctly classified 94.1% of the best male swimmers (based on age, 30-min test, 6 × 50 m at 1:30, shoulder extension, arm span, and height), and 71.0% of the best females swimmers (30-min test, horizontal floating, velocity at 50 m, and age). Chronological age was the main predictor of performance in this age category. Main predictive variables pertained to the anthropometric (particularly in males), specific fitness (aerobic speed and endurance), and technical domains (particularly in females). In these ages competitions should be organized according to year of birth and not by age categories.

Osteoarthritis is a degenerative joint disease. The knee and hip joints are the most frequently affected. Treatments fall into three main categories: pharmacological, non-pharmacological, and surgical. Treatments can be applied alone or in combination. In the last few years, within the non-pharmacological category have been a growing importance of physical exercise programs aimed to reduce pain in knee and hip joints. The purpose of this review was to summarize evidence for the effectiveness and structure of exercise programs on pain in patients with hip and knee osteoarthritis. To that end, several databases were searched, retrieving 33 studies that evaluated the influence of different exercise programs on pain. These studies were grouped according to the characteristics of the exercise program: land-based intervention (strength program, Tai Chi, aerobic program), aquatic intervention (hydrotherapy), and mixed exercise programs. The main conclusions drawn were: (i) despite recommendations for the use of exercise programs as pain therapy in patients with hip and knee osteoarthritis, very few randomized clinical studies were conducted; (ii) the structure of the exercise programs (content, duration, frequency and duration of the session) is very heterogeneous; (iii) on overall, exercise programs based on Tai Chi have better results than mixed exercise programs, but without clear differences.

Objective: The purpose of this meta-analysis was to examine the evidence for the effectiveness of aerobic exercise interventions on reducing insulin resistance markers in obese children and/or adolescents. A secondary outcome was change in percentage of body fat. Methods: A computerized search was made from seven databases: CINAHL, Cochrane Central Register of Controlled Trials, EMBASE, ERIC, MEDLINE, PsycINFO, and Science Citation Index. The analysis was restricted to randomized controlled trials that examined the effect of aerobic exercise on insulin resistance markers in obese youth. Two independent reviewers screened studies and extracted data. Effect sizes (ES) and 95% confidence interval (CI) were calculated, and the heterogeneity of the studies was estimated using Cochran's Q-statistic. Results: Nine studies were selected for meta-analysis as they fulfilled the inclusion criteria (nZ367). Aerobic exercise interventions resulted in decreases in fasting glucose (ESZK0.39; low heterogeneity) and insulin (ESZK0.40; low heterogeneity) and in percentage of body fat (ESZK0.35; low heterogeneity). These improvements were specifically accentuated in adolescents (only in fasting insulin), or through programs lasting more than 12 weeks, three sessions per week, and over 60 min of aerobic exercise per session. Conclusions: This meta-analysis provides insights into the effectiveness of aerobic exercise interventions on insulin resistance markers in the obese youth population.

No abstract

The purpose of this meta-analysis was to examine the evidence for the effectiveness of exercise interventions on the resting blood pressure (systolic and diastolic) of obese children. A computerized search was made of seven databases using keywords. Effect sizes (ES) and 95% confidence intervals were calculated, and the heterogeneity of the studies was estimated using Cochran's Q-statistic applied to the effect size means. Nine randomized controlled trial (RCT) studies were selected for review as satisfying the inclusion criteria (n = 205 exercise, 205 control). The main cumulative evidence indicates that the exercise programmes with a frequency of three sessions weekly lasting longer than 60 min had a moderate effect on systolic blood pressure (ES = -0.46, I(2)  = 27%), and programmes of under 12 weeks with more than three sessions weekly were beneficial in terms of reduction of diastolic blood pressure (ES = -0.35, I(2)  = 78%).