title: Relationships between isokinetic knee strength, single-sprint performance, and repeated-sprint ability in football players.
abstract: Previous research has demonstrated that muscular strength of the knee extensors is related to the speed an athlete can produce during a single-sprint performance. Football players, as well as many other athletes on the field and the court, execute multiple sprints during the course of a match. The purpose of this study was to examine the relationships between leg strength, single-sprint speed, and repeated-sprint ability. Thirty-eight football players from 3 codes (soccer, rugby league, rugby union) completed a 12- x 20-m repeated-sprint protocol and were evaluated for peak isokinetic knee extension and flexion torque at 60 degrees .s(-1), 150 degrees .s(-1), and 240 degrees .s(-1). Although single-sprint performance correlated with peak extensor and flexor torque at all velocities, the strongest correlation was observed between relative knee extensor torque at 240 degrees .s(-1) and the initial acceleration phase (0-10 m) of the single-sprint performance (r = -0.714, p < 0.01). However, the data suggest that factors other than strength contribute to repeated-sprint ability. This finding provides new evidence in elucidating the relationship between strength and repeated-sprint performance.
authors.affiliation: School of Human Movement Studies, Charles Sturt University, Bathurst NSW, Australia.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Newman
authors.forename: Kyle M
authors.initials: KM
authors.lastname: Tarpenning
authors.forename: Frank E
authors.initials: FE
authors.lastname: Marino
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D005538:Football / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D016014:Linear Models; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D012420:Running / Q000502:physiology*; D012916:Soccer / Q000502:physiology*; D019415:Torque