title: The effects of resisted sled-pulling sprint training on acceleration and maximum speed performance.
abstract: OBJECTIVE
  The purpose of the present study was to examine the effects of resisted (RS) and un-resisted (US) sprint training programs on acceleration and maximum speed performance.
  
  
  METHODS
  Twenty-two male students (age 20.1+/-1.9 y, height 1.78+/-7 cm, and weight 73+/-2 kg) completed RS (n=11) or US (n=11) sprint training programs. The RS group followed a sprint-training program with 5 kg sled pulling and the US group followed a similar sprint-training program without sled pulling. The training program consisted of 4x20 m and 4x50 m maximal runs, and was applied 3 times/week for 8 weeks. Before and after the training programs the subjects performed a 50 m run and the running velocity of 0(-1)0 m, 10(-2)0 m, 20-40 m and 40-50 m was measured. In addition, stride length and stride frequency were evaluated at the 3(rd) stride in acceleration phase and between 42-47 m in maximum speed phase.
  
  
  RESULTS
  The RS improved running velocity in the run sections 0(-1)0 m and 0(-2)0 m, while in US group the running velocity in all run sections in acceleration phase remained unchanged (p>0.05). In contrast, RS training had no effect on running velocity in maximum speed phase, whereas US improved running velocity in 20-40 m, 40-50 m, and 20-50 m run sections (p<0.05). Stride rate increased only after RS in acceleration phase (+7.1+/-2.9%; p<0.05), whereas stride length increased only after US in maximum speed phase (+5.5+/-2.5%; p<0.05).
  
  
  CONCLUSIONS
  Sprint training with 5 kg sled pulling for 8 weeks improves acceleration performance (0(-2)0), while un-resisted sprint training improves performance in maximum speed phase (20-40) in non-elite athletes. It appears that each phase of sprint run demands a specific training approach.
authors.affiliation: Department of Physical Education and Sport Science, Sports Performance and Coaching Laboratory, Aristotelio University of Thessaloniki, Thessaloniki, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Zafeiridis
authors.forename: P
authors.initials: P
authors.lastname: Saraslanidis
authors.forename: V
authors.initials: V
authors.lastname: Manou
authors.forename: P
authors.initials: P
authors.lastname: Ioakimidis
authors.forename: K
authors.initials: K
authors.lastname: Dipla
authors.forename: S
authors.initials: S
authors.lastname: Kellis
mesh_terms: D000054:Acceleration; D000328:Adult; D001696:Biomechanical Phenomena; D006801:Humans; D008124:Locomotion / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D010806:Physical Education and Training; D010809:Physical Fitness; D011446:Prospective Studies; D012420:Running / Q000502:physiology*; D013647:Task Performance and Analysis