Heavy Sled Pulls: Superior to light for improving sprints (*study)
Towing a weighted sled can help you sprint faster. Common wisdom holds that a light sled that allows maximum speed without breaking sprint form is the ideal way to make use of this training modality. But is this true? Is towing a light sled to allow for running mechanics closer to actual sprint form is superior to pulling heavier loads? To answer this question, scientists recruited twenty-one physically active men were randomly allocated to heavy or light-load weighted sled towing groups for two training sessions per week over eight weeks. The subjects in the heavy group used a load that reduced their speed by ~30%, while the sleds in the light group reduced sprint speed by ~10%. Before and after the training, the subjects performed a 10-m sprint test (time was measured at 5 and 10 m). The heavy group significantly improved both the 5- and 10-m sprint time by about 5.7% and 5.0% at 5 and 10 meters, respectively. But only the ten meter sprint time was improved significantly in the light group, and only by about 3.0 +/- 3.5% in the light group.
Moving a heavy sled is more difficult to start, so it’s no surprise that the people who trained heavier got off the line more quickly. Obviously these were very short sprints, but if we look at average distances per carry in the NFL for a halfback or a fullback, 5-10 meters is more than enough.
