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Little is known about the influence of different types and sources of social support on physical activity in adolescents. The aim of this study was to analyse the association between physical activity and different types and sources of social support in adolescents. The sample consisted of 2,859 adolescents between 14–19 years of age in the city of João Pessoa, in Northeastern Brazil. Physical activity was measured with a questionnaire and social support from parents and friends using a 10-item scale five for each group (type of support: encouragement, joint participation, watching, inviting, positive comments and transportation). Multivariable analysis showed that the types of support provided by parents associated with physical activity in adolescents were encouragement for females (P < 0.001) and adolescents between 14–16 years of age (P = 0.003), and transportation (P = 0.014) and comments (P = 0.037) for males. The types of social support provided by friends were: joint participation in male adolescents (P < 0.001) and in these 17–19-year-olds (P < 0.001), and comments in both genders (males:P = 0.009; females:P < 0.001) and 14–16-year-olds (P < 0.001). We conclude that the type of social support associated with physical activity varies according to its source, as well as the gender and age of the adolescents. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyse the characteristics of the asymmetries in the dominant and non-dominant limbs when kicking stationary and rolling balls. Ten experienced Brazilian amateur futsal players participated in this study. Each participant performed kicks under two conditions (stationary ball vs. rolling ball) with the dominant and non-dominant limbs (five kicks per condition per limb). We analysed the kicking accuracy, ball and foot velocities, angular joint displacement and velocity. The asymmetry between the dominant and non-dominant limbs was analysed by symmetry index and two-way repeated measures ANOVA. The results did not reveal any interaction between the condition and limb for ball velocity, foot velocity and accuracy. However, kicking with the dominant limb in both kicks showed higher ball velocity (stationary ball: dominant – 24.27 ± 2.21 m · s‒1and non-dominant – 21.62 ± 2.26 m · s‒1; rolling ball: dominant – 23.88 ± 2.71 m · s‒1and non-dominant – 21.42 ± 2.25 m · s‒1), foot velocity (stationary ball: dominant – 17.61 ± 1.87 m · s‒1and non-dominant – 15.58 ± 2.69 m · s‒1; rolling ball: dominant – 17.25 ± 2.26 m · s‒1and non-dominant – 14.77 ± 2.35 m · s‒1) and accuracy (stationary ball: dominant – 1.17 ± 0.84 m and non-dominant – 1.56 ± 1.30 m; rolling ball: dominant – 1.31 ± 0.91 m and non-dominant – 1.97 ± 1.44 m). In addition, the angular joint adjustments were dependent on the limb in both kicks (the kicks with non-dominant limb showed lower hip external rotation than the kicks with the dominant limb), indicating that the hip joint is important in kick performance. In conclusion, the kicks with the non-dominant limb showed different angular adjustments in comparison to kicks with the dominant limb. In addition, kicking a rolling ball with the non-dominant limb showed higher asymmetry for accuracy, indicating that complex kicks are more asymmetric. [ABSTRACT FROM PUBLISHER]

The aim of this study was to assess the validity (Study 1) and reliability (Study 2) of a novel intermittent running test (Carminatti's test) for physiological assessment of soccer players. In Study 1, 28 players performed Carminatti's test, a repeated sprint ability test, and an intermittent treadmill test. In Study 2, 24 players performed Carminatti's test twice within 72 h to determine test–retest reliability. Carminatti's test required the participants to complete repeated bouts of 5 × 12 s shuttle running at progressively faster speeds until volitional exhaustion. The 12 s bouts were separated by 6 s recovery periods, making each stage 90 s in duration. The initial running distance was set at 15 m and was increased by 1 m at each stage (90 s). The repeated sprint ability test required the participants to perform 7 × 34.2 m maximal effort sprints separated by 25 s recovery. During the intermittent treadmill test, the initial velocity of 9.0 km · h−1 was increased by 1.2 km · h−1 every 3 min until volitional exhaustion. No significant difference (P > 0.05) was observed between Carminatti's test peak running velocity and speed at VO2max (v-VO2max). Peak running velocity in Carminatti's test was strongly correlated with v-VO2max (r = 0.74, P < 0.01), and highly associated with velocity at the onset of blood lactate accumulation (r = 0.63, P < 0.01). Mean sprint time was strongly associated with peak running velocity in Carminatti's test (r = −0.71, P < 0.01). The intraclass correlation was 0.94 with a coefficient of variation of 1.4%. In conclusion, Carminatti's test appears to be avalid and reliable measure of physical fitness and of the ability to perform intermittent high-intensity exercise in soccer players. [ABSTRACT FROM PUBLISHER]