Effects of intermittent-endurance fitness on match performance in young male soccer players.

The purpose of this study was to examine the effect of specific endurance (Yo-Yo Intermittent recovery test level 1, Yo-Yo IR1) on match performance in male youth soccer. Twenty-one young, male soccer players (age 14.1 +/- 0.2 years) were involved in the study. Players were observed during international championship games of corresponding age categories and completed the Yo-Yo IR1 on a separate occasion. Physical (distance coverage) and physiological match demands were assessed using Global Positioning System technology and heart rate (HR) short-range telemetry, respectively. During the match (two 30-minutes halves), players covered 6,204 +/- 731 m, of which 985 +/- 362 m (16%) were performed at high intensities (speed >13 kmxh, HIA). A significant decrement (3.8%, p = 0.003) in match coverage was evident during the second half. No significant (p = 0.07) difference between halves was observed for HIA (p = 0.56) and sprint (speed >18 kmxh, SPR) distances. During the first and second halves, players attained the 86 +/- 5.5 and 85 +/- 6.0% of HRmax (p = 0.17), respectively. Peak HR during the first and second halves were 100 +/- 4 and 99.4 +/- 4.7% of HRmax, respectively. Yo-Yo IR1 performance (842 +/- 352 m) was significantly related to match HIA (r = 0.77, p < 0.001) and total distance (r = 0.65, p = 0.002). This study's results showed that specific endurance, as determined by Yo-Yo IR1 performance, positively affects physical match performance in male young soccer players. Consequently, the Yo-Yo IR1 test may be regarded as a valid test to assess game readiness and guide training prescription in male youth soccer players.

Aerobic fitness in futsal players of different competitive level.

Recently the use of small-sided games (mainly 5 vs. 5) proved to be a valid training method to improve aerobic fitness in soccer. Thus, it could be hypothesized that professional futsal (soccer 5-a-side indoor version) players may possess a well-developed aerobic fitness as a consequence of training and game participation. The aim of this study was to examine maximal oxygen uptake (VO2max), ventilatory threshold (VT), and running economy (RE, VO2 at 8 kmxh) of futsal players of different competitive levels to determine whether aerobic fitness is a discriminative variable for futsal success. Subjects were 24 male futsal players from a professional top-ranked second division team (PT, n = 11) and a semi-professional top-ranked third division team (ST, n = 13). Aerobic fitness was assessed with a running protocol performed on a motor-driven treadmill. Professional team and ST players' VO2max were 62.9 +/- 5.3 and 55.2 +/- 5.7 mLxkgxmin, respectively (p < 0.05). RE was 34.1 +/- 2.7 and 32.4 +/- 2.7 mLxkgxmin for PT and ST, respectively (p >0.05). PT and ST attained VT at 70.5 +/- 2.7 and 71.3 +/- 5.2% of VO2max, respectively (p > 0.05). Results showed that VO2max may be considered a competitive-level dependent physical variable in futsal. VO2max values of or above 60 mLxkgxmin are advisable to play futsal at the professional level.

Effects of different practice conditions on acquisition, retention, and transfer of soccer skills by 9-year-old schoolchildren.

This study was designed to examine effects of three practice models, blocked, variable, and combined, on the acquisition, retention, and transfer of new motor skills. 67 subjects (M age = 9.5 yr., SD = .3) from the fourth year of primary school (31 boys and 26 girls) were assigned at random to three different practice groups (Blocked = 22, Variable = 23, Combined = 22) to study acquisition of two skills, dribbling a soccer ball and kicking a soccer ball at a stationary target using the dominant foot. All participants received a pretest and posttest, a transfer test, and a retention test 2 wk. later. Analysis showed significant improvement after practice of kicking skills by the three groups but not in the dribbling skills, for which only the combined practice group showed any notable improvement. At the end of acquisition, the combined practice group had significantly better performance on the dribbling task than the other two groups. However, the only differences noted in performance of kicking the ball with the dominant foot were by combined practice and blocked groups.