Stride Length & Stride Frequency are multifactorial outcomes, not causes.
The key is to look at how fast the center of mass travels, not about strides and frequency unless you are able to see ground contact time and mechanics with a high degree of precision and accuracy. In my presentation I did on the 100m dash recently, the big question is what has changed over the last 20 years. Bodies are a little stronger from training and perhaps extra servings of yams, but gravity and distance are constants. No matter how fast you reposition legs gravity will be the same rate. No matter how much force you put into the ground, an optimal release angle is necessary. So what is changing? Race modeling has made athletes do a better job at the entire race. No more top speed guys. No more accelerators. No more closers. The entire race is getting better. Even parts of the race are getting better as well. People are able to string together entire phases better and the splits are showing that.
Stride length and stride frequency are descriptors, not characteristics that live in isolation. It’s like the biomotor abilities, while speed is a quality, I have never seen an ugly 12.3 mps split done by a skinny runway model. We know Usain is not embarrassing people with his squat or clean numbers, and his plyometric program is not likely to be something that will make a triple jumper puke by just observation. A huge component is genetic and the fact a focus on running is there. The natural adaptation to speed is a decrease of ground contact time and stride length. How much does each one change is individual. Usain bolt doesn’t have the same ground contact time of Dwayne Wade, while their heights are similar. In fact the elites all have less ground contact time than those that are slower, and are likely to have stride lengths that match their anatomical heights.
The takeaway here is to focus on great mechanics and loading, and the adaptations will happen. We never see explosive strides at 3 meters with longer ground contact times. We never see 1 meter steps that look like a blur. Most will fall in the 2.2-2.5 meter lengths with 4.5-4.8 strides per second and usually one’s anatomy and physiology has a signature that is developed by just time and work. Instead of thinking about what ways we can make the stride more powerful with weights and plyometrics, think about are we exposing athletes to speed work while fresh and with enough technique that the stimulus will create what we are seeking.