I saw this and thought it might be of interest to ELITETRACK members:
Med Sci Sports Exerc. 2010 Oct 26. [Epub ahead of print]
Elite Sprinting: Are Athletes Individually Step Frequency or Step Length Reliant?Salo AI, Bezodis IN, Batterham AM, Kerwin DG.
PURPOSE: The aim of this study was to investigate the step characteristics amongst the very best 100 m sprinters in the world in order to understand whether the elite athletes are individually more reliant on step frequency (SF) or step length (SL).
METHODS: A total of 52 male elite level 100 m races were recorded from publicly available television broadcasts with 11 analysed athletes performing in 10 or more races. For each run of each athlete, the average SF and SL over the whole 100 m distance was analysed. To determine any SF or SL reliance for an individual athlete, the 90% confidence interval (CI) for the difference between the SF: time vs. SL: time relationships was derived using a criterion nonparametric bootstrapping technique.
RESULTS: Athletes performed these races with various combinations of SF and SL reliance. Athlete A10 yielded the highest positive 90% CI difference (SL reliance) with a value of 1.05 (CI range 0.50 to 1.53). The largest negative difference (SF reliance) occurred for athlete A11 as -0.60 with the CI range of -1.20 to 0.03.
CONCLUSION: Previous studies have generally identified only one of these variables to be the main reason for faster running velocities. However, this study showed that there is a large variation of performance patterns amongst the elite athletes, and overall, SF or SL reliance is a highly individual occurrence. It is proposed that athletes should take this reliance into account in their training with SF reliant athletes needing to keep their neural system ready for fast leg turnover and SL reliant athletes requiring more concentration on maintaining strength levels.
While I don’t think this is a bridge that most coaches will ever have to cross, I think it could potentially lead to some interesting individualization to maximize performance. One question that would need to be asked though, is that since direction and magnitude of force application at ground contact strongly impacts both stride length and stride frequency what individualizations would actually need to be made?