Effects of physical activity on body mass and composition of school-age children and adolescents with overweight or obesity: Systematic review focusing on intervention characteristics.

OBJECTIVE: The characteristics of physical activity (PA) interventions to improve body mass and composition in pediatric populations are unclear. This systematic review summarized the effects of PA on those outcomes in school-age children and adolescents with overweight or obesity, focusing on training components (frequency, intensity, duration, and type - FITT). METHODS: Databases were searched for controlled trials applying exclusive PA and including children (5-12 y) or adolescents (13-17 y) with overweight/obesity. RESULTS: Twenty-seven trials yielding 34 interventions were included. PA was recreational (children: k = 9, n = 478), systematized (children: k = 18, n = 565); or combined (children: k = 7, n = 205). Successful interventions were performed for 6- to 35 weeks (mostly 12-14 weeks), 2- to 5 d/wk (mostly 3 d/wk), during 8- to 60 min (mainly 60 min) with moderate to high intensity (60-90% maximal heart rate or 40-70% heart rate reserve). Half of the interventions applying recreational (4 out of 8), 59% of systematized (10 out of 17), and 57% of combined (4 out of 7) interventions reported improvements in body mass or composition, especially body fat. Benefits were more often reported for body composition (18 out of 34 interventions) than body mass (8 out of 34 interventions), irrespective of the age group. CONCLUSION: Recreational and systematized PA may improve body mass, and particularly body composition in school-age children and adolescents with overweight or obesity. Successful programs were performed for at least six weeks and applied a PA amount consistent with the minimum recommended for pediatric populations (≥60 min of moderate-to-vigorous PA at least 3 d/wk).

Joint and muscle injuries in men and women CrossFit® training participants.

OBJECTIVE: Verify the incidence and rate of joint and muscle injuries with the practice of CrossFit® and the potential risk factors for injuries in men and women. METHODS: A total of 184 CrossFit® participants (97 men and 87 women). A questionnaire was conducted based on characterization, training routine, injuries, and additional information. The incidence refers to the number of new cases of injury in the sample during the CrossFit® training. The injury rate was calculated by estimating the number of weekly training hours and converted into the number of injuries per 1000 training hours. RESULTS: Among the participants, 38.6% reported some type of injury, being joint injuries (83.1%) and/or muscle injuries (45.1%). The injury rate was 3.4/1000 h, with men having a higher rate. The location of the joint injuries was shoulders, wrists, and elbows, in addition to the lumbar spine in women. As for muscle injuries, the deltoid, upper back muscles, and quadriceps femoris were the most reported in men and deltoid, trapezius, upper back muscles, and gastrocnemius in women. CONCLUSIONS: A better understanding of the anatomical distribution of the injuries may help coaches prescribe the most adequate workout that may reduce the likelihood of injuries occurring in CrossFit® training participants. It was demonstrated that gender, experience, weekly frequency, and previous injuries are important factors, and professionals must be concerned with the assessment of the participants and with an individualized progression in order to avoid risks.