You wanna hear something insane? You can make your left arm stronger by training your right arm and never even touching your left arm.
This is called the cross-education or cross-transfer effect. I talked about it in a blog a little while back. I got a bunch of questions about it. So I wanted to go into a little bit more depth about the neurology behind this so that you can understand it and understand how to begin applying it immediately for yourself and for your clients.
So in this previous blog, I talked about the idea of this cross-transfer, cross-education effect as an enormously powerful brain-based tool for decreasing pain and helping areas that are currently injured to maintain strength. Now, this has been known about for a really long time, but we also understand much more about the neurology behind it. And if you understand basic movement neurology, cross-training makes total sense. However, in the current world, most people say, hey, I have a left bicep injury, so what am I gonna do? Well, if you go see a classically trained professional, they’re typically gonna tell you to do a lot of therapy on this side, try to rest it, maybe begin doing a little bit of strength work over time. But is there a more efficient way that we can approach this, both to improve strength, to improve movement, and to decrease pain beginning from day one? The answer is yes, and the answer is working on the opposite side of the body.
So before I go any further, if you are a movement professional, you’re interested in bringing brain-based training into what you do, you wanna understand this stuff at great depth so that you can apply it very intentionally and very precisely with your clients, go to the pinned comment, DM us on Instagram, or drop us an email because we’d love to share more information with you.
Now, having said that, whenever we start diving into the cross-education effect, number one, I said, this has been known about for a long time. So in science, whenever we’ve known about something for a long time, the next question is, are there details available that tell us how to use it most effectively? And right now, the answer is yes.
There was actually a really cool kind of meta review that came out about a year and a half ago looking at the cross-education slash cross-transfer effect for strengthening. And that’s what I’m gonna talk about today because I wanna give you some ideas from that study. I’m also gonna give you some very practical real-world ideas, stuff that we have seen work very, very well in our clients over the last 20 plus years of doing brain-based training.
So let’s assume for today that I have a left bicep injury, right? I did something. I’m having a lot of pain. Maybe I have very limited flexion right now without pain. I can’t really do much training. I’m doing typical soft tissue work and icing and electrical therapy, whatever. It’s not getting better, all right? So maybe that’s the client that comes to see you today. If you have that client, one of the first things that we wanna start with is applying cross-education for both pain and for performance, right? Now, whenever we start dealing with pain, we are going to simply think about exercising the opposite side muscle, right? So if I have a left bicep issue, I’m gonna start by training my right bicep.
Whenever we go into this, we have options then. We can choose isometric exercise, right? Where we’re just holding resistance for a prescribed period of time. We have dynamic exercises where I’m doing both concentric or an eccentric exercise. And then if you have machines, you can do isokinetics and then you can apply some electric stimulation. So these have all been looked at.
Now, from a motor training perspective, meaning I wanna increase strength in this damaged area, that’s where I wanna start. But then I’m gonna give you a really important practical real-world caveat. So whenever we look at increasing strength of this injured or painful side, the most effective way that we’ve seen that is a combination of electrostimulation, so putting like a muscle stim unit on the right bicep while I am doing dynamic exercises. I’m doing concentric and eccentric, all right? The next step down is isokinetics. Now, isokinetics means I’m doing a bicep curl at the same speed because the machine is forcing me to do that. Most of us don’t have access to isokinetic equipment and a lot of people are uncomfortable with the idea of throwing pads on someone and using electrical current, particularly if this isn’t in your licensure or in your practice. So what then would be the most practical?
Well, the most practical tool right now that carries over the most in terms of generating strength on the non-moving side is eccentric exercise. So if I was doing this, I could use, if I typically can’t use this arm, but I might wanna try to get into a bicep curl position without actually doing the concentric work. So if I’m using a band, I will often have people do a little dip. Now they’re in the position that they can just do a long three to four second eccentric of this working bicep and they just repeat that, all right? So we would be typically using rep ranges that are synonymous with creating strength. Now, obviously I’m not doing a super heavy band here, but I encourage you to not go super heavy, go for a little bit more volume, but focus on slow controlled eccentrics as one of the best tools for increasing strength on the opposite side.
From there, we then have the concentric version, all right? So eccentrics first, then concentric, and then finally, the tool that provides, from what we’ve seen, the lowest transfer in terms of strength is just isometrics.
Now, whenever we actually compare these, the differences are not huge. We’re talking about maybe two to 3% or less difference between isometric, concentric and eccentric. So you don’t have to get overly worried about, okay, am I choosing the right modality here? I just wanted to make sure that you understood what the current meta reviews look like.
Now that’s the science of it. Now let’s talk real world in practice. Here’s what I typically do. I almost always start with isometrics. Why? Because if I have an injured arm, painful arm, whenever we go into the literature looking at pain, isometrics work better than concentric, eccentric, dynamic and anything else. So in our world, because we know that doing isometric work on the right arm will actually decrease pain on the left arm through some kind of complicated neurology that we’re not gonna take time to get into right now, but it does, this is all normal if you understand neuroscience. We like to start with isometrics.
So typically for the first one to two weeks when people are having left arm pain or left shoulder pain and I’m working the opposite side, we’re gonna focus on multi angle, multiple intensity isometrics on the working side. Typically what you’ll see within three to six minutes of doing different versions of isometrics is a significant drop in the pain levels. And more importantly, because again, we’re not only decreasing pain, we’re increasing strength. You will typically also begin to see more capacity to go through a range of motion with less pain. So whenever I say multiple angles, we typically will do full stretch. We’ll come up about 30 degrees, we’ll do more. We’ll come up another 30 degrees and do more. So typically three positions for your isometrics is great. Whenever we do these, I tend to have people begin with long hold isometrics at a lower intensity, again, based on other research.
So you have a lot of ideas here. Just remember the basics are this. If someone has pain and weakness in an area, look at the muscles in that area and then perform exercises on the opposite side of the body for those same muscles. We recommend if they have pain, prioritizing long hold isometrics at three different positions, again, multi angle. Do that for one to two weeks. And as they begin to have a decrease in pain, I have more ability to actually go through a range of motion, then switch over to eccentrics and concentrics, because when you do this, you can take rehab that may have required previously three months to get them out of pain and get them moving again, and significantly reduce that because you’re actually getting them out of pain faster and you’re maintaining strength all while never working the injured side, all right?
Hope you’ve really enjoyed this. Again, if you’re a movement professional, go to the pin comment, DM us on Instagram or drop us an email because we’d love to share more of this brain-based education stuff with you, particularly if you’re great at biomechanics, you’re already great at what you do, adding the next layer of neurology is often the step that will prepare you and the results that you get with your clients to the next level, all right? I hope you guys enjoyed this. Have a great day.
