| Autor: |
Zisi M; Sports Performance Laboratory, School of Physical Education & Sport Science, National & Kapodistrian University of Athens, Ethnikis Antistaseos 41, 172 37 Dafni, Greece., Stavridis I; Sports Performance Laboratory, School of Physical Education & Sport Science, National & Kapodistrian University of Athens, Ethnikis Antistaseos 41, 172 37 Dafni, Greece., Agilara GO; Sports Performance Laboratory, School of Physical Education & Sport Science, National & Kapodistrian University of Athens, Ethnikis Antistaseos 41, 172 37 Dafni, Greece., Economou T; Sports Performance Laboratory, School of Physical Education & Sport Science, National & Kapodistrian University of Athens, Ethnikis Antistaseos 41, 172 37 Dafni, Greece., Paradisis G; Sports Performance Laboratory, School of Physical Education & Sport Science, National & Kapodistrian University of Athens, Ethnikis Antistaseos 41, 172 37 Dafni, Greece. |
| Abstrakt: |
The aim of this study was to investigate the effects of heavy sled towing using a load corresponding to a 50% reduction of the individual theoretical maximal velocity (ranged 57-73% body mass) on subsequent 30 m sprint performance, velocity, mechanical variables (theoretical maximal horizontal force, theoretical maximal horizontal velocity, maximal mechanical power output, slope of the linear force-velocity relationship, maximal ratio of horizontal to total force and decrease in the ratio of horizontal to total force) and kinematics (step length and rate, contact and flight time). Twelve ( n = 5 males and n = 7 females) junior running sprinters performed an exercise under two intervention conditions in random order. The experimental condition (EXP) consisted of two repetitions of 20 m resisted sprints, while in the control condition (CON), an active recovery was performed. Before (baseline) and after (post) the interventions, the 30 m sprint tests were analyzed. Participants showed faster 30 m sprint times following sled towing ( p = 0.005). Running velocity was significantly higher in EXP at 5-10 m ( p = 0.032), 10-15 m ( p = 0.006), 15-20 m ( p = 0.004), 20-25 m ( p = 0.015) and 25-30 m ( p = 0.014). No significant changes in sprint mechanical variables and kinematics were observed. Heavy sled towing appeared to be an effective post-activation potentiation stimulus to acutely enhance sprint acceleration performance with no effect on the athlete's running technique. |
