Review 2 – Are Isometrics Overrated for Speed Development?

Cross-sectional studies are an easy way to describe the relationship between 2 two or more factors. However, caution should be taken when wanting to use the results of such studies to inform our decision-making processes – aka what to do. Let’s bear in mind that without a strong and accurate causal model, we can’t infer any causation from a cross-sectional analysis and, as we’ve all heard, yet more often than not ignore, is that correlation doesn’t imply causation. This is merely a snapshot of one distinct timepoint without really knowing what contributed to the emergence of this specific phenomenon. Yet could we use such results to rule out certain training interventions – aka knowing what not to do?!

Isometric Strength and Sprinting

The most interesting part for me was the comparison of isometric strength between the groups, as ultimately, you must be able to apply more force to hit higher velocities. When we look at the relative torque values of the tested groups, it might cause some disbelief. Contrary to what we would assume no difference between elite and sub-elite. I want to challenge our assumption that whatever isometric training we do in the gym may or may not do what we all hope it does after all, especially in populations that are already well-trained. It seems like it doesn’t matter much how much you can ISO push. After all, does it?

Foot Strength

Since both relative muscle size and strength of the plantar flexors did not differ in any meaningful way, I want to extrapolate those findings to the capacities of your foot and speculate that there is again no meaningful difference. Yet, there seem to be many assumptions about the importance of the foot, MTP, or big toe and how to train it best in isolation. Do you really think you can somehow elicit higher forces in whatever gym exercise than what’s happening in a sprint? Really?

So, my takeaways from this are maybe we are way too confident in our assumptions about isometric strength and foot strength. How much time do we want to then invest in improving those two? Are we really making any difference or rather just wasting valuable training time? What do you think?