Purpose:
The purpose was to examine whether there is a positive acute effect of resisted and assisted sprinting on the kinematics and performance of regular 20-m sprints.

Methods:
The total of 15 female team handball players were involved in a counterbalanced crossover design three sprint sessions consisting of (1) seven normal 20-m sprints, (2) seven sprints alternating normal and resisted sprints, and (3) seven sprints alternating between normal and either resisted or assisted sprints in a single session.

Results:
The main finding was that only resisted sprints had an effect on the first normal 20-m sprint. However, this was only the case after one resisted run (from 3.59 to 3.54 s; 2% improvement). Using several resisted sprints did not have any positive effect upon the normal sprints, but probably caused fatigue, as shown in the increased contact times and decreased vertical stiffness, step length, and rate. Assisted running did not cause any changes to the normal sprints.

Conclusions:
Resisted sprints can cause a positive effect in normal 20-m sprint performance (2%) after the use of one resisted effort in team handball players. However, the small positive effect is negated if several resisted efforts are performed, causing more fatigue than a positive response. Therefore, it is recommended that multiple resisted sprint efforts are not performed when seeking to enhance 20-m sprint performance in these athletes.