I’ve been noticing this trend when I run. If I try to follow the main recommendations right now that to run faster I need to increase my steps per minute I get uncomfortable (fair enough, I’m not used to running like that), my knee hurts more (that’s a little more troublesome), and now that I’m stuck inside on a treadmill I know that I also run slower and get tired faster. But I thought this was the key to running faster, so how does that work?
When I up the treadmill speed I find I can last significantly longer at a high speed if I focus on pushing off more rather than moving my legs faster. Well, as it turns out, I’m not the only one. Weyand, Sternlight, Bellizzi, and Wright (2000) found that applying greater ground force, ie pushing off the ground harder, had a greater impact on top speed than did moving your legs faster. There was a pretty small difference in leg speed that was not statistically significant but there was a significant difference in force (1.26 times greater for a runner with a top speed of 11.1 m/s vs 6.2 m/s).
Nummela, Keranen, and Mikkelsson (2007) found that the force needed to be applied horizontally to contribute to maximum running speed and that the force needed to be applied quickly to maximize the amount of distance someone gets for a certain amount of energy. This makes sense, when I’m running I want to run forward not bound upwards so applying force so that it propels me across the ground makes sense. I assume that this is why the run of a 100 metre sprinter looks nothing like the run of someone who is preparing for a high jump.
I wonder if the force being applied quickly relates to why there has been such focus on the number of steps per minute. Is there a perception that the more steps you take, the faster you are applying the force? In many of the sports I do (paddling, figure skating, running as examples) there seems to be a balance between taking faster strokes/steps and how much force I can apply. Presumably the goal, if I’m working on speed is to apply my greatest amount of horizontal force while achieving the highest stroke/step rate. But there comes a point when I’m moving too fast to maintain a high force. This makes perfect sense to me. And here I see a flaw in the resources I have seen about increasing my running speed. They focus on step rate and forget to mention that I need to apply the greatest force I can. As I improve, in theory, I will be able to apply greater force at higher step rates but I have to train to do that.
So what does this mean for my training? I probably still need to spend some time trying to make my legs move faster to get them used to speed but I can’t forget about applying force. As a result, changing my run so that I can move my legs faster doesn’t help me because I won’t be able to apply the force when I’m ready. And I need to improve how much force I can apply (bring on the weights and other targeted training tools).
Nummella, A., Keranen, T., Mikkelsson, L. O. (2007). Factors related to top running speed and economy. International Journal of Sports Medicine, 28(8), 655-661.
Weyand, P., Sternlight, D., Bellizzi, M., & Wright, S. (2000). Faster top running speeds are achieved with greater ground forces not more rapid leg movements. Journal of Applied Physiology, 89(5), 1991-1999. https://doi.org/10.1152/jappl.2000.89.5.1991