Blog By Coach Dr Aaron Uthoff

Dr Aaron Uthoff from Auckland University of Technology and the Sport Performance Research Institute New Zealand (SPRINZ) talks about Wearable Resistance for Sprinting.

I’m here today to share with you some insights how you can use EXOGEN Wearable Resistance Calf Sleeves to take your sprint game to the next level. I’ve been researching how to get athletes faster and applying these learnings to my practice for nearly a decade now. Along that journey, I work with athletes all the way from youth grassroot level to Olympic medalists at the top of their game. And what I’ve learned along those journeys is that my real passion lies in this area of bridging the gap between research and practice. So that’s taking what happens with these researchers the scientists do in a lab setting now with these coaches do in their practical application working with athletes on the day to day basis and melding it together and then teaching people how to apply these scientific principles of sports and exercise science to optimize their athletes performance.


One aspect that’s been really interesting to me is this idea of transference; is what you’re doing in the gym or what you’re doing on the field, these exercises that you’re always working on, that people tell you are to get you better, faster, stronger, are they actually transferring to making you faster on the track, the court or the field? Well, several years ago I was invited to be a part of this research team looking at the effects of this novel resistance training tool: Wearable Resistance on the Effects of Sprinting Technique and Force Application.

From that research it just opened my mind to this world of how we can apply the idea of specificity to your training and I haven’t stopped researching it since. When you think about it, speed in its most simple form is just strike length or step length; how far you step on each stride and stride frequency. So how fast you can turn your legs over in order to beat your opposition to the ball or an order to win that score and try, whatever it might be. What we found is when we load 200, 400, 600 grams, this here 200 grams (that’s 8 ounces for any of those North American folks, that’s half a pound) on to the calf, this overloads a stride frequency component of that model. This is done primarily because they have about a 2 percent longer ground contact time and about a 3 percent longer flight time. What I’m talking about with ground contact time is the time that your foot hits strikes the ground in a single support and that flight time is the time where both feet are off the ground before you hit your next step. What was really interesting from all this research is that athletes can get faster using it, it can overload the stride frequency component but what doesn’t happen is you don’t see differences in ground reaction forces either vertical or horizontal so this leads us to understand that when you load the calf during sprinting where the primary overload occurs is in rotation. So it happens here, not just straight down in the ground, not just straight back behind you. That’s just one of the fantastic things about wearable resistance, especially the calf sleeves that we can use.

Along with this, what we’re also seeing is if you’re getting greater rotational inertia so you’re getting greater overload the joints. When you load the calf what happens is you load across the muscles across the knee and across the hip okay so theoretically what you can do is just say that this is going to train those muscles and there’s likely going to be adaptations to improve performance and primarily in the realm of neurological adaptation so you’re firing frequency is probably going to be a bit higher your synchronization will likely increase so therefore being able to enhance your sprint capabilities.

When it comes to integrating calf sleeves into your training, there are three things that you need to consider:
1. How to wear the sleeves
2. Loading terminology and placements for it
3. How are you gonna progressively overload this over about 6 weeks and integrate it into your training cycle

How do you wear it? The calf sleeves are pretty simple. They’ve got a top and a bottom, and what you do is it’s pretty simple. You just look at the tag; it’s going to tell you what your size is; it’s gonna tell you whether it’s a right or a left and then you just slap that bad boy. Strap that baby down and boom there you go. What you’re looking for here is you’re looking to ensure that this gap is on the outside, go towards that and malleolus. You want to make sure that these straps are nice and tight around the top to hold it in place above that calf, the bottom strap is just kind of there to hang on.

About loading terminology, there are 3 ideas that you need to need to think about. If you’ve ever taken an anatomy or physiology class, you might be familiar with these terms. The first one is anterior / posterior. Anterior / posterior refers to either the front or the back of the body, so are you either going to load the anterior aspect of it or are you gonna load the posterior aspect. Next, you gotta think about is whether you’re gonna go medial or lateral. When you think of medial / lateral, medial you’re just thinking towards the center of body. Am I going to take this, I’m going to take the fat end, the belly portion of the load, put it right to the inside; that is a medial loading strategy. The next one is going to be lateral so you just take that fat end of the load. Lateral just means away from the center line of the body.

Finally what you got to think about is where you’re going to go proximal or distal okay Proximal just means that it is closer to the center of mass okay so I’m here it’s gonna be closer to my knee right so I load that end up the belly up that is proximally loaded or I can load here that is proximal. Now as I progress I can progress that distally all right so move it further towards the ankle what that’s going to do is that’s going to increase rotational inertia so it’s going to provide more overload. It’s it’s fairly important to think that with this loading placement comes your progression and you gotta be smart and safe with how you’re doing it. How are you gonna progressively overload this safely?

How are you gonna integrate this into your training program? It’s pretty easy 3-step process. Weeks 1 & 2, you’re just gonna take 200 grams, put it proximally belly up and there you go. You do your sprint training, you take care of business, you make sure that you get a little bit faster. For weeks 3 & 4, what we’re looking to do is you’re just gonna add another 200 grams for that. So now we’re up to 400. Same thing you don’t need to switch up what you’re doing in your program. You just keep doing your day to day business, you keep doing your drills, you keep doing your sprints, you keep getting faster! This is just gonna overload that component. Now to finish off these, final week 5 & 6, what you’re gonna do is you’re gonna move the final 200 grams anterior. Again, belly side up, now you’ve got 600 grams on your calf. That’s enough; this is a simple safe and effective progression that you can use to ensure that you’re getting you and your athletes faster.