The Effectiveness of Resisted Sprinting to Improve Short Distance Sprint Performance in Young Athletes
Speed is an important athletic quality and needs to be developed in young athletes, this may be best achieved using specific forms of sprint training. Resisted sled training is a sprint specific form of training widely used by coaches and practitioners. The two modes of resisted sled training that exist are sled pushing and pulling, with limited research available for pulling and little, if any, available for pushing in any population. The overarching question that guided this thesis was “what are the acute and chronic training responses to sled pushing and pulling in young athletes?”
The aims of the thesis were to: review existing literature related to acute and chronic training responses to resisted sled pushing and pulling; examine the reliability, linearity, and utility of individual load-velocity profiles to prescribe training loads during sled pushing and pulling in young athletes; assess the effectiveness of unresisted and resisted sled pull and sled push training on short distance sprint performance across a wide array of individualised loads; and, provide practical programming guidelines on how to integrate resisted sled training into an athlete’s training.
The main findings of this thesis were: 1) across existing literature little uniformity exists with regard to prescription of load for resisted sled training although heavier loads appeared to provide a stimulus for higher horizontal force application. Loads can be applied across different zones of training such as technical competency, speed-strength, power and strength-speed. 2) Sled pushing and pulling produce a highly linear relationship (r > 0.95) between load and velocity. The slope of the load-velocity relationship was found to be reliable (CV = 3.1%), with the loads that cause a decrement in velocity of 25, 50 and 75% also found to be reliable (CVs = <5%). However, there was large between-participant variation (95%CI) in the load that caused a given Vdec in both sled pushing and pulling. Loads of 14-21, 36-53, 71-107 and 107-160% body mass (%BM) caused a Vdec of 10, 25, 50 and 75% in sled pulling. Loads of 23-42, 45-85 and 69-131% body mass (%BM) caused a Vdec of 25, 50 and 75% in sled pushing. 3) Both forms of resisted sprint training demonstrated a clear trend for greater and more consistent improvements in sprinting force, power and performance over short distances when training with heavier sled loads (as compared to a lighter load or unresisted sprint training).
Several practical applications may be offered from the findings. Due to the linearity and reliability of the load-velocity relationship, coaches are urged to prescribe individualised sled loads based on a target decrement in velocity rather than simply prescribing all athletes the same load as a set percentage of body mass. Both sled pushing and pulling were effective sprint specific modes of training to enhance overall sprint performance, with the latter found to be more sprint specific due to the use of the arms. Heavier loads during both forms of resisted sled training appeared to yield the greatest benefit to young athletes in short distance sprint performance, however a targeted approach to sled loading may influence different phases of the sprint.