However, based on this knowledge, it is of interest to compare the speed and stride characteristics of each phase expressed relatively to the level of motor abilities, primarily jumping ability, and strength of lower extremities. The relationship between stride length (SL) and stride frequency (SF) for maximizing running speed in different phases of a 100 m sprint performed by athletes of a different sports level ( Delecluse et al., 1995 Mann and Sprague, 1980 Ferro et al., 2001 Gejer et al., 1999 Ito et al., 2006 Letzelter, 2006 Mackala, 2007 Salo et al., 2011) and even untrained athletes ( Babić et al., 2011 Chatzilazaridis et al., 2012 Coh et al., 1995 Letzelter, 2006) remains poorly investigated. The amount (running distance) of body-lean an athlete exhibits is directly proportional to upper body strength. In turn, Frye (2000) claimed that the technical model of the initial acceleration phase can be achieved by pushing with the drive leg, which requires a forward body-lean from the ground up. Maximal strength, acquired in the squat and power clean exercises, has been significantly correlated with sprint performance ( Wisloff et al., 2004). The sprinter also requires strong leg and back extensor muscles. Therefore, the greatest transfer of the explosiveness to sprinting can occur. These exercises have similar contact times as sprinting during the initial acceleration phase. Young (1992), Mero and Komi (1994), and Rimmer and Sleivert (2000) suggested that bounding may be considered a specific exercise using the stretch shortening cycle for the development of acceleration. The deceleration is marked only in the last 10 m section of the 100 m dash ( Brüggemann et al., 1999).Īt the beginning of the sprint run, the ability to produce a great concentric force/power and to generate high velocity during acceleration is of primary importance ( Bissas and Havenetidis, 2008 Mero et al., 1992). In this phase the sprinter reaches peak stride length, stride frequency, and maximum velocity. It lasts until the sprinter achieves the level of maximum running speed. Thus, a third transition sub-phase (35–60 m) takes place only at the elite level. Top-level sprinters reach their maximum speed between 50 and 70 m ( Ae et al., 1992 Brüggemann and Glad, 1990 Gajer et al., 1999) and are able carry on for another 20 m, although very seldom for 30 m. When the acceleration phase is of sufficient length and optimum value of running speed, the sprinter is not able to maintain the maximum speed and a long deceleration phase occurs. The acceleration phase may be subdivided into several sub-phases: the initial or starting acceleration (0–12 m), which is mainly characterised by a constant increase of stride length and the main acceleration (12–35 m). The duration and more insightful breakdown of each phase mainly depend on the level of sprint abilities ( Mackala, 2007). The 100 m sprint can be divided into 3 distinct phases: block start with acceleration, maximum speed, and deceleration ( Ae et al., 1992 Brüggemann and Glad, 1990 Shen, 2000).
The most important factor for differences in maximum speed development during both the initial and secondary acceleration phase among the two sub-groups was the stride frequency (p<0.01). A strong correlation was also found between a 1-repetition maximum back squat and a standing long jump, standing five jumps, and standing ten jumps (r = 0.88, r = 0.87 and r = 0.85), but again only for sprinters. The recorded times of the 10 and 30 m indicated that the strongest correlations were found between a 1-repetition maximum back squat, a standing long jump, standing five jumps, standing ten jumps (r = 0.66, r = 0.72, r = 0.66, and r = 0.72), and speed in the 10 m sprint in competitive athletes.
Additionally, the Ward method of hierarchical cluster analysis was applied. The Spearman ranking correlation coefficient was computed to verify the association between variables.
An independent t-test for establishing differences between two groups of athletes was used. Sprinting performance (10 m, 30 m, and 100 m from the block start), strength (back squat, back extension), and jumping ability (standing long jump, standing five-jumps, and standing ten-jumps) were tested. Eleven competitive male sprinters (10.96 s ± 0.36 for 100 with 10.50 s fastest time) and 11 active students (12.20 s ± 0.39 for 100 m with 11.80 s fastest time) volunteered to participate in this study. The goal of this study was to examine the relationship between kinematics, motor abilities, anthropometric characteristics, and the initial (10 m) and secondary (30 m) acceleration phases of the 100 m sprint among athletes of different sprinting performances.
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