The acute effects of heavy sled towing on subsequent sprint acceleration performance

Objectives: The purpose of this study was to assess the practical use of heavy sled towing and its acute implications on subsequent sprint acceleration performance. Design and Methods: Eight healthy male varsity team sport athletes (age: 21.8 ± 1.8years, height: 185.5 ± 5.0cm, weight: 88.8 ± 15.7kg, 15m sprint time: 2.66 ± 0.13s) performed sprints under three separate weighted sled towing conditions in a randomized order. Each condition consisted of one baseline unweighted sprint (4-min pre), the sled towing sprint protocol: (1) 1 × 50% body mass, (2) 2 × 50% body mass, (3) 3 × 50% body mass (multiple sprints interspersed with 90s recovery), and 3 post-testing unweighted sprints thereafter (4, 8, 12-min post). All sprints were conducted over a 15m distance. Results: Significantly faster sprint times for the 3 × sled towing protocol were identified following 8-min of rest (p = 0.025, d = 0.46, 2.64 ± 0.15s to 2.57 ± 0.17s). When individual best sprint times were analyzed against baseline data, significantly faster sprint times were identified following both 1 × (p = 0.007, d = 0.69, 2.69 ± 0.07s to 2.64 ± 0.07s) and 3 × (p = 0.001, d = 0.62, 2.64 ± 0.15s to 2.55 ± 0.14s) sled towing protocols. Within the 3 × condition, all athletes achieved fastest sprint times following 8-12 min of rest. Conclusions: The findings from the present study indicate that a repeated bout of sled towing (3 × 50% body mass) leads to the enhancement in subsequent sprint acceleration performance, following adequate, and individualized recovery periods. (Journal of Trainology 2017;6:18-25)