Vertical vs. Horizontal Force in Sprinting


Here’s a response I wrote for an interview I did over at as part of their Friday Five Series. To read the entire interview please click here and be sure to share and like on facebook and twitter. Q: “Max speed” is often the hot topic with many blogs, especially those in strength and condoning. With huge debate on horizontal and vertical forces as well as specific muscle groups such as calves, hamstrings, glutes, quads, and even core and upper body being the holy grail, what are the real bottlenecks in top speed? Can the force plate data and of Ralph Mann and Peter Weyand show enough evidence that a combination of the right force profile in all planes is necessary for world class performance? A:While many think there’s a single magic bullet, I don’t think something as complex as speed can be distilled to an exercise, drill, specific force vector or workout. The attainment of top speed is multi-factorial with many things being intertwined and I think anyone who claims to have the secret has immediately discredited themselves for having any advice worth hearing. In my opinion, there are two interlinked bottlenecks to top end speed. The first is simply the ability to accelerate. It sounds simple, but the people with the best top end speed tend to accelerate smoother, longer and with more mechanical proficiency at every phase from the start until they are upright at top end speed. The second limiter is the ability to generate forces eccentrically. The faster you run, the more load you experience at touchdown. This requires the athlete to have the capacity to resist those downward forces. It also requires the athlete to overcome the inevitable breaking forces in order to harness the potential elastic response even before they can ultimately produce a beneficial propulsive force (upward AND forward) in a very limited amount of time. The available force plate data has some serious methodological limitations right now and while there’s useful information to be gleaned, I think we’re still getting a very unclear picture of what’s happening. I’m excited to see what results are produced when sprinters across a wide performance continuum (good to elite) are studied sprinting across 3D force platforms on flat ground at true maximum velocity rather than treadmills at sub-maximal speeds. I suspect what we’ll find is that the whole vertical force vs. horizontal force debate is going to be somewhat of a moot point based more on semantics rather than what is actually happening or what can actually be trained. I believe that from a coaching standpoint, the change of force vector is so fast in elite sprinting (ground contact