Moderate Load Resisted Sprints Do Not Improve Subsequent Sprint Performance in Varsity-Level Sprinters

Area of Science:

• Sports Science
• Athletic Performance
• Biomechanics

Background:

• Resisted sprint training (RST) is a common method to improve acceleration ability in athletes.
• While evidence suggests RST can enhance successive sprint performance in team sport athletes, its acute effects on sprint-trained athletes are less understood.

Purpose of the Study:

• To investigate if resisted sprints with moderate loads (45% body mass) induce a potentiation effect, improving subsequent maximal sprint performance in varsity-level sprinters.
• To determine the acute effects of resisted sprint training on 0-5 m and 0-20 m sprint times.

Main Methods:

• Twenty competitive sprinters were divided into resisted sprint training (RST) and unresisted sprint (URS) groups.
• Each group performed a pre/post maximal 20-m sprint protocol, with 3 resisted or unresisted sprints in between, repeated over 4 sessions.
• Sprint times over 0-5 m and 0-20 m were measured.

Main Results:

• No significant differences in sprint times were observed between the RST and URS groups for either 0-5 m or 0-20 m distances.
• Sprint time changes in the URS group were Δ <0.01 ± 0.03 s (0-5 m) and Δ 0.013 ± 0.04 s (0-20 m).
• Sprint time changes in the RST group were Δ <0.01 ± 0.03 s (0-5 m) and Δ <0.01 ± 0.04 s (0-20 m).

Conclusions:

• Resisted sprints using sled-equivalent loads of 45% body mass do not effectively potentiate subsequent sprint performance in varsity-level sprinters.
• Higher resistance loads may be required to elicit a potentiation effect in highly trained sprinters.
• Current moderate-load RST protocols are insufficient for acute performance enhancement in this athletic population.