The effect of a bilateral training intervention on sprint start performance of experienced male sprinters

Bilateral transference research has recently shown evidence that the training of the preferred and non-preferred leg can improve overall performance, through the development and adaption of motor processes. The current study used a bilateral training intervention on a sprint start to determine if the same effects were exhibited. Twelve male participants, all of whom were county to national level sprinters took part in the study. An intervention group (n=6) undertook an 8-week bilateral training intervention for the sprint start, consistently changing the foot on the front block between preferred and non-preferred leg. A control group (n=6) used the same programme but only with the preferred leg lead. Participants were assessed Pre, Mid and Post intervention over the 8-week period. The lab-based testing assessed a total of ten sprint starts over a five-metre distance, with both the preferred and non-preferred leg performing five trials when positioned at the front block. Results established no significant change (P= > 0.05) in five-metre sprint performance for the preferred (P = 0.136; ηp2 = 0.181) and non-preferred (P=0.716; ηp2 = 0.033) lead leg trials across stages between groups. Several significant results across stages (P=<0.05) were found for kinematic and ground reaction force variables. A key interaction (P= < 0.05) was found at the block push off during non-preferred leg trials for the intervention group, where the hip had greater extension. Further changes to performance were found across stages for both groups, for hip, knee, and ankle kinematics, as well as the braking impulse (P= < 0.05). Despite these changes the 8-week intervention implemented did not result in any changes to sprint start performance over the five-metre distance. Future research should look to further assess the application of a bilateral training program to sprint start performance, with further assessment over the acceleration phase after the first two strides.