The purpose of this study was to examine the effect of 10 weeks' 40-m repeated sprint training program that does not involve strength training on sprinting speed and repeated sprint speed on young elite soccer players. Twenty young well-trained elite male soccer players of age (±SD) 16.4 (±0.9) years, body mass 67.2 (±9.1) kg, and stature 176.3 (±7.4) cm volunteered to participate in this study. All participants were tested on 40-m running speed, 10 × 40-m repeated sprint speed, 20-m acceleration speed, 20-m top speed, countermovement jump (CMJ), and aerobic endurance (beep test). Participants were divided into training group (TG) (n = 10) and control group (CG) (n = 10). The study was conducted in the precompetition phase of the training program for the participants and ended 13 weeks before the start of the season; the duration of the precompetition period was 26 weeks. The TG followed a Periodized repeated sprint training program once a week. The training program consisted of running 40 m with different intensities and duration from week to week. Within-group results indicate that TG had a statistically marked improvement in their performance from pre to posttest in 40-m maximum sprint (-0.06 seconds), 10 × 40-m repeated sprint speed (-0.12 seconds), 20- to 40-m top speed (-0.05 seconds), and CMJ (2.7 cm). The CG showed only a statistically notable improvement from pre to posttest in 10 × 40-m repeated sprint speed (-0.06 seconds). Between-group differences showed a statistically marked improvement for the TG over the CG in 10 × 40-m repeated sprint speed (-0.07 seconds) and 20- to 40-m top speed (-0.05 seconds), but the effect of the improvement was moderate. The results further indicate that a weekly training with repeated sprint gave a moderate but not statistically marked improvement in 40-m sprinting, CMJ, and beep test. The results of this study indicate that the repeated sprint program had a positive effect on several of the parameters tested. However, because the sample size in this study is 20 participants, the results are valid only for those who took part in this study. Therefore, we advice to use repeated sprint training similar to the one in this study only in periods where the players have no speed training included in their program. Furthermore, the participants in this study should probably trained strength, however, benefits were observed even without strength training is most likely to be caused by the training specificity.

Ists' heat round development, and age. A database of 100-m sprint results and corresponding reaction times from 1,319 sprinters participating in different International Association of Athletics Federations world championships during the time period 2003–9 was compiled for this investigation. Seiko was the official timekeeper of the world championships in this study. Seiko uses a silent gun system for time initiation and false start detection. Their Slit Video system captures the runners at the finish line up to 2,000 images per second with high-resolution cameras. Our results indicate that there was a significant relationship (p < 0.01) between reaction time and 100 m running time, with a shared variance of 8.5 and 10.8% for males (r = 0.292) and females (r = 0.328), respectively. Reaction times (0.166 ± 0.030 seconds) of males were significantly shorter (p < 0.01) than those for females (0.176 ± 0.034 seconds). No relationship was observed between reaction time and height. Male finalist sprinters had substantially shorter reaction times in the finals (0.142 ± 0.017 seconds) compared with round 1 (0.161 ± 0.024 seconds), round 2 (0.155 ± 0.020 seconds), and the semifinals (0.153 ± 0.022 seconds). Female finalist sprinters obtained their fastest reaction times during the semifinals (0.153 ± 0.018 seconds). The best reaction times were registered at the age of 26–29 years for males (0.150 ± 0.017 seconds) and >30 years for females (0.153 ± 0.020 seconds), but reaction times across different age categories were also positively correlated with 100 m performance (p < 0.05). Considering the findings of this study, the results suggest that sprinters' reacting abilities affect their sprint performance over 100 m. This study provides magnitude estimates for the influence of performance level, gender, body height, finalists' heat round, and age on reaction time among world-class sprinters, which we believe to be of great interest for coaches and athletes in sports involving reacting skills....

Between vertical jump measures and sprint speed over 10, 20, and 40 m in professional basketball players. Thirty-three professional basketball players aged (±SD) (27.4 ± 3.3 years), body mass (89.8 ± 11.1 kg), and stature (192 ± 8.2 cm) volunteered to participate in this study. All participants were tested on squat jump, countermovement jump, and 40-m running speed. The results show that all jump measures in absolute terms were correlated significantly to running performance over 10-, 20-, and 40-m sprint times. None of the jumping performance peak powers and reactive strength were found to have a correlation to running speed times in absolute term. Furthermore, all jump height measures relative to body mass except reactive strength had a marked and significant relationship with all sprint performance times. The results of this study indicate that while there is a strong and marked relationship between 10-, 20-, and 40-m sprint, there is also a considerable variation within the factors that contribute to performance over these distances. This may indicate that, separate training strategies could be implemented to improve running speed over these distances....

The aim of this study was to compare the effects of in-season combined resisted agility and repeated sprint training with strength training on soccer players' agility, linear single sprint speed, vertical jump, repeated sprint ability (RSA), and aerobic capacity. Twenty well-trained elite female soccer players of age ± SD 19.4 ± 4.4 years volunteered to participate in this study. The participants were randomly assigned to either the agility and repeated sprint training group or to the strength training group. All the participants were tested before and after a 10-week specific conditioning program. The pretest and posttest were conducted on 3 separate days with 1 day of low-intensity training in between. Test day 1 consisted of squat jump (SJ), countermovement jump (CMJ), and RSA. Test day 2 consisted of a 40-m maximal linear sprint and an agility test, whereas a Beep test was conducted on test day 3 to assess aerobic capacity. The agility and repeated sprint training implemented in this study did not have a significant effect on agility, although there was a tendency for moderate improvements from 8.23 ± 0.32 to 8.06 ± 0.21 seconds (d = 0.8). There was a significant (p < 0.01) and moderate-positive effect on Beep-test performance from level 9.6 ± 1.4 to level 10.8 ± 1.0, and only a trivial small effect on all other physical variables measured in this study. The strength training group had a positive, moderate, and significant (p < 0.01) effect on Beep-test performance from level 9.7 ± 1.3 to level 10.9 ± 1.2 (d = 1.0) and a significant (p < 0.05) but small effect (d = 0.5) on SJ performance (25.9 ± 2.7 to 27.5 ± 4.1 cm). Furthermore, the strength training implemented in this study had a trivial and negative effect on agility performance (d = -0.1). No between-group differences were observed. The outcome of this study indicates the importance of a well-planned program of conditioning that does not result in a decreased performance of the players, the great importance of strength and conditioning specialist in implementing the training program, and the importance of choosing the time of the year to implement such conditioning training programs. However, the fact that the present training program did not cause any decline in performance indicates that it is useful in maintaining the soccer players' physical performance during the competition period.

Ingebrigtsen, J, Dillern, T, and Shalfawi, SAI. Aerobic capacities and anthropometric characteristics of elite female soccer players. J Strength Cond Res 25(12): 3352-3357, 2011-This study investigated aerobic capacities and anthropometric characteristics within a group of 29 elite female soccer players. The purpose was to identify and establish aerobic capacities and anthropometric characteristics for these players and to look for possible positional differences between keepers, defenders, midfielders, and attackers. We did this by measuring standard anthropometrical variables and maximal oxygen (VO(2)max) and anaerobic threshold (AT). One-way analysis of variance revealed no significant differences among anthropometric or physiological variables. However, a trend (p = 0.062) toward positional differences was found within running speed at AT. A subsequent Tukey post hoc test showed differences (p = 0.04) between keepers and defenders, with the latter running faster (∼1.7 km·h) at AT. The present results suggest that few anthropometric and physiological differences exist between playing positions in elite female soccer players. Furthermore, the current results indicate that present elite players' physiological characteristics are similar to those previously shown, despite the rapid changes of the female soccer game. Based on well-established knowledge that different playing positions within a soccer team ought to have distinct capacities, we recommend regular testing programs to be able to construct and implement tailored training programs for players' physical capacities with respect to the demands of their playing positions.

The aim of the present study was to assess the reliability and validity of the Newtest Powertimer 300-series® portable contact mat and photocells (Newtest Oy, Finland). The participants were 20 male soccer players aged 19.1±3.5 years. The validity and reliability of the Powertimer (contact mat and photocells) were assessed in a comparison of a laboratory testing method (force platform and photocells) and the Newtest Powertimer system. All participants were tested on 40-m sprint, countermovement jump, and squat jump. The results showed that the Powertimer was a reliable instrument for both jumping and running. The system did not show any marked systematic bias (P < 0.05) and the random error associated with it was negligible. A comparison of the laboratory testing method with the Powertimer revealed that the Powertimer contact mat and photocells had poor validity and the bias in measurement differed from that of the laboratory testing method (P < 0.05). The Newtest Powertimer testing system was shown to be a useful instrument for measuring jump height and running speed. However, if a comparison of overall values of jumping height is intended, it is important to use the same testing system, because different systems give different results. It is also advisable to use this equipment only if no other “gold standard” equipment is available.