Let’s explore another way of getting you or your athletes faster. Previously we looked at how you can use limb loaded wearable resistance (WR) to train step frequency. This article unpacks how you can train step length to improve speed.
Determinants of Speed
Just to recap, if you want to get faster getting from A to B, whether it be a 100 m, 1000 m or 10,000 m, mechanically speaking it is simple, as all you need to do is increase your step frequency and/or your step length as these are the two primary determinants of speed or getting between the start and finish faster (see Figure 1). Simply put, if you can increase your step length and maintain your frequency then you’ll get to the finish quicker. Conversely, if you get your feet down more often to apply force against the ground and maintain step length, that finish line will appear quicker. If you can do both then you are going to be a real winner and smash your PBs. This article, however, will focus on step length.
Wearable Resistance and Step Length
I am the first to acknowledge that there are a number of ways to increase step length, from technical cueing and increasing range of motion to specific strength and power drills/training. However, one of the easiest ways to improve step length is to put a vest on and run. It is as simple as that.
If you can remember back to my “Get Faster: Step Frequency” post, I explained why limb loaded WR was ideal for overloading step frequency. So why is vest loading a better choice for inducing step length adaptation. Let me explain.
I have tried to show in Figure 1 that the two types of WR garments offer very different forms of overload. The vest is more of a vertical overload, whereas limb loaded WR is more of a rotational overload at the hip and/or knee depending if you are wearing shorts or calf sleeves. Limb loading as explained in my previous article has greater influence on swing velocity and therefore step frequency. Vest loading however, due to the vertical overload has a greater influence on the rise and fall of the centre of mass (COM) whilst airborne. That is, because of the vest loading exerting a downward vertical force, the upward path of the COM of the runner is less - you remember “for every action there is an equal and opposite reaction” don’t you? I have tried to show this diagrammatically in Figure 2. To the bottom line then, with vest loading you are in the airborne phase for a shorter duration and therefore your step length will be less.
Take Home Message
You can improve speed by overloading step frequency with limb loaded WR whereas a better choice for step length is vest loaded WR. Determine what your athlete needs (step length or frequency training) and program accordingly. If in doubt or unsure what your athlete needs, wear both vest and limb loaded WR whilst training.