The purpose of this study was to compare the track block start (BS), rhythm step (false step) (RS), and forward step (FS) on sprint start ability in male Division I collegiate football linebackers. Although the blocks are not practical in the sport of football, they were used as a gold standard for sprint acceleration. Sixteen collegiate football linebackers (age, 20.9 ± 1.1 years; height, 72 ± 3.0 in; mass, 97 ± 4 kg) performed 3 repetitions each of the BS, FS, and RS. Each sprint was videotaped through 5 m. The time from 0 to 2.5 m (t2.5), 0 to 5 m (t5), and 2.5 to 5 m (tsplit) were calculated for each trial using all 3 different techniques, and the best times for each treatment was recorded. Block start resulted in significantly lower t2.5 and t5 compared with RS and FS. Rhythm step had significantly lower t2.5 and t5 compared with FS. There was no difference in tsplit between any of the 3 treatments. The results indicate that using the blocks is optimal for sprint performance through 2.5 and 5 m. Rhythm step outperformed FS through both 2.5 and 5 m, suggesting that for collegiate football linebackers, RS is superior to FS.

The purpose of this study was to investigate the effects of 2 stretching protocols on stretch-shortening cycle performance in female Division I soccer players and female club rugby players. Fifteen soccer and rugby players (20.1 ± 5.9 years, 170.5 ± 14.2 cm, 70.4 ± 22.3 kg) participated in 3 test sessions with different treatments. The first treatment involved a warm-up of 10 minutes of exercise on a cycle ergometer (warm-up only [WO]), the second was this warm-up followed by static stretching (SS), and the third was this warm-up followed by dynamic stretching (DS). The treatments were administered randomly to negate an order effect. Each treatment was immediately followed by a reactive strength index (RSI) test requiring the athletes to drop off a box (45 cm in height) on to a force plate and upon landing immediately jump into the air while minimizing contact time (CT, milliseconds) and maximizing flight time (FT, milliseconds). The RSI was FT: CT. Repeated measures analysis of variance indicated that a significant treatment effect existed for RSI (F = 7.95, 2; p = 0.002) and FT (F = 7.43, 2; p = 0.003) but no significant effect for CT (F = 1.53, 2; p = 0.235). The RSI and FT were significantly greater in DS compared with that in SS and WO. Dynamic stretching is the preferred warm-up before an athletic event involving considerable jumping.

There was no difference in the optimal loads for MP (40, 50, and 60% 1RM) and PP (50, 60, and 70% 1RM) between CO and SSC movements. An enhancement of power during the initial 200 ms of the concentric phase of SSC movements was observed. Greater time to reach PP was the reason for the enhancement in PP output observed in CO movements. The CO training regimen associated with the sport of rowing also may have lessened the effect of the SSC.

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