Episode 44 | Early Conditioning Options in ACL Rehab

What’s up guys, and welcome back to another episode on the ACL Athlete Podcast. Today’s episode number 44, and we are talking about early conditioning options in ACL rehab. This topic came up after a question I got from an athlete based on a post I made, and this is actually a question I get all the time. I feel like this was a good time to talk about this specific topic. I’m going to read the post to create a little bit of context here.

It says, initially in ACL rehab, return to running isn’t for cardiovascular or aerobic benefits, it’s for building capacity and tolerance to load on the knee. If the goal is cardiovascular work, this should be accomplished via other means with off-feet conditioning. The caption is running is commonly viewed as a cardiovascular/aerobic activity for athletes. This is where education is vital. When athletes know the why behind what they’re doing, it changes the output, it changes their intent, it reduces the odds of overdoing it. We need less grumpy knees in ACL rehab, amen! We need more why and education for athletes during this process.

I want to talk about this briefly because I think this is a very important point for any of you who are listening, getting back into running, or planning to get back into running. Maybe you have a very pissed-off knee right now because you are running. Maybe this can give you a little bit of context or some input to understand, okay, what is my goal with running, and then therefore that can help to strategize what you’re doing with it. And so what happens is, is that athletes will get cleared to run, and then all of a sudden they are running more and more, they’re accumulating volume.

And a lot of times they’re starting to get back into it because they want to build up their cardio, they’re excited to be running, and we totally get this. I completely get it. I have a lot of athletes who are always itching to start running. But there’s always a process leading up to it, and it doesn’t always go as smoothly as we hope sometimes. And so then that’s why it’s important to understand the goal of returning to running.

And that goal for the initial stages is to build up your capacity and to get that knee ready for loading. When you run, your body experiences anywhere from around 2.5 times your body weight. And then at the knee itself, it could be anywhere from five to six times your body weight between the patellofemoral joint and your tibiofemoral joint. There’s a lot of weight and a lot of load and stress and forces going through your knee. That’s why I stress a proper strategy and plan to build up your running because of these forces that your knee will feel, and also throughout your body.

And what happens is that athletes get cleared for this, they push too hard. They end up overdoing it because their intention is to build up their cardio again, as opposed to getting the knee ready for running and loading. And then they do it a little too hard because they want a good sweat. And then the knee swells up a little bit and then you might have to take a step back with the running, as opposed to, okay, let’s make sure we monitor. And the intent is load and tolerance with the knee rather than cardiovascular work for your body. 

The question I got was, what do you suggest for cardio instead? I say that you can’t do running necessarily for cardio early in ACL. So then what are the options? And so before we dive directly into this, I want to a step back and talk about some terminology so that we’re all on the same page. My goal is to keep this pretty simple, not too far into the weeds. But we’ll talk a little bit about this terminology. What you’ll typically hear is conditioning, cardio, energy system development, which is more in the sports or strength and conditioning field.

For conditioning, that is just generally the ability to sustain work, force, power output, that’s that in-shape feeling. And this is typically relative to the sport or activity. There are differences between football or swimming, a 5K full marathon, Ironman’s, skiing. Some of those are sprint, some of those are more endurance-based. All of these will be dictated and implemented specifically for your conditioning to make you feel in shape for those specific sports. The term ‘cardio’ is short for cardiovascular training. Most people reference this in terms of just general fitness for breaking a sweat via their own preferences. This might be going out for a run, maybe it’s cycling, maybe it’s a hit workout. Even though it’s cardio, it’s just essentially a way for them to get a workout in or break a sweat.

And then there’s this other term called energy system development, which is more in the sports or strength and conditioning world that you hear. And the three systems that fall within that are the ATP_Pcr. You can hear this as other terms as well called phosphagen system or anaerobic alactic, which this all just means immediate energy. And it is something that is something like a fast sprint, so maybe within 6 to 10 seconds. And then you have glycolysis, which is the next one, and this is also referred to as anaerobic lactic. And this could be something for think about, like a medium output, something around like 30 seconds. And then the last one is aerobic, and that’s more longer lower intensity, a minute-plus, typically. And this is the one that a lot of people will think of more as the cardio, more as the steady state endurance stuff where you’re training that aerobic energy system. 

What energy system, your training will depend on your sport or activity. And in this case, we’re talking specifically to ACL rehab in the early stages. The point of this episode is to talk about options other than running. We’re talking about probably the first three to five months realistically of ACL rehab. And sure, you might be introducing running and starting to build that up. But again, the goal should be to build tolerance and load at the knee and see how your knee develops that running volume rather than it being the means of getting this conditioning work that you want. It comes back to the goal, and right now the goal is what is going to get us that conditioning or cardio work that we’re feeling, and then we can dive into the specific energy systems if we want. But let’s just keep this very broad, in terms of how can we continue to get that sweat, get that work in like we want. And still feel like an athlete, while we can’t run and get that through that means. 

To answer this question, what would you suggest for cardio in those early phases? I want to talk about this term called off-feet conditioning. And this is something that we talk about the differences are on-feet or off-feet conditioning. On-feet, you could think of high impact, specifically running, sprinting, things that are going to put a lot of stress through the joints or through your body. And then there’s certain ones that are going to be low impact. And this is something where it’s decreased demands on the joints and the muscles, which is something we kind of need for the early parts of ACL rehab. Because we want to achieve the goal of getting some conditioning and some cardio work in. But we don’t want to essentially aggravate our knee. And so that is the thing that’s really important here. 

And off-feet conditioning can be a really good option to do that. And so some of the benefits are for rehab. It could be for building capacity. And that’s just essentially the ability to do more work or produce more output. It could be for active recovery; it could be for balancing that running volume if you’re building it up; and the knee loading during the ACL rehab process, which is something that I love to do with my athletes. We’ll integrate a lot of bike work or circuit work or even just some aerobic work that is not related to running because we’re still trying to build those up. And so then they will have things like this for their energy system development. They still get that sweat feeling and they get that feeling as an athlete without having to stress that joint as much.

For me, it will always come back to what the goal is, the current phase, and where the ACL athlete is in the process with me. But early, we will focus more on aerobic work. So that’s lower intensity, longer duration, and then as they can tolerate more, and then we move towards more anaerobic for better power output, more higher intensity stuff with shorter durations. But that doesn’t mean you can’t do that early either. It just depends on where the athletes are. And specifically, after ACL surgery or injury, I like to work on a little bit more of an aerobic base because it also has lower intensity demands. And we could still train the heart rate and get a sweat going without feeling like it’s too taxing on the body.

Equipment options for this, it can be a bike. Ideally, I like the ones with the arms and the foot pedals, so you can also get your arms involved. So let’s say you’re a week post-op and you want to get on the bike. Typically, if you’re using the ACL side, then that’s going to be something where you’re going to be working on the range rather than cranking through repetitions or minutes or things like that. It’s nice to be able to prop that leg up on a rested foot pedal, if you will, where the center of the wheel is.

And then maybe you could use the non-operated side and your arms to be able to still get some work in and some movement in. You have the rower, which will depend on your knee flexion range and the comfort of that. Obviously, you don’t want to jam that knee flexion. There’s the SkiERg, which is really great. You could take out the legs if you need to and just sit on a box. You have the battle ropes, which I like a lot. It gets a little bit more upper body movement, and that always gets your heart rate up. You’re talking about using med balls, maybe a prowler or a sled, depending on where you’re at in the process. A VersaClimber, swimming, there are so many different methods to do this. It’s just going to come back to how you want to do it. 

And then if we’re talking about programming or how we’re going to design, how to implement these, which I know can always be tough. And there’s so many different ways to do this, but that’s going to come back to the goal of what you’re trying to do. Is it to get more steady state, lower intensity work? Or is it more higher intensity, shorter duration? Then there are different options of things like high-intensity continuous training; EMOM  which is every minute on the minute; steady state training where you don’t stop and you’re just continuously going at a lower intensity; there’s Tabatas which are typically a higher intensity and then short rest; there are circuits that you can design multiple different ways which are essentially based on movement and typically time and rest ratios. And so there are all of these different options. 

One thing I’m going to give you an example of is aerobic. Let’s say you’re maybe two months out and you’ve got the full range and you’re able to ride on the bike for a decent bit. Then maybe it’s just riding the bike for 30 minutes, and you’re aiming for a heart rate of 130 to 150. This is something related to cardiac output, which is essentially how can we train our cardiovascular system and our aerobic system to be able to build a good base at a lower intensity and allow our heart to fill with blood, and then being able to push that blood out. And this is always a good means that I get a lot of athletes to work and start early. You could also mix this up. And do 10 minutes on the bike, 10 minutes on the SkiErg, and then maybe 10 minutes on the rower. Instead of being on the bike for 30 because you hate that and you want to poke your eyes out, maybe you just switch every 10 minutes and you still get a similar effect and you get some variety in there. There are lots of options to do this. 

And then if we maybe jump onto more of the higher intensity side, let’s say we’re trying to get in some more sprint-related work, but we’re still trying to stay off our feet and staying with this theme and this goal of trying to build up more of the power output or higher end stuff. Then we’re looking at maybe five to eight rounds of bike sprints for 10 seconds on, and maybe it’s 50 to 100 seconds for rest. The rest is typically longer with this, and it’s because there’s such a high output. And if we’re working on the proper energy system which is the one that sprint like the ATP-Pcr, then we need to have a high output and then a long rest and recover to be able to have that same output on the next rep. If you’re just cranking through it 10 seconds on, and then you rest 20 seconds and then you do another 10 seconds on. One, it will crush your soul. Two, it’s probably not as high output as you want, maybe the first one or the second one. But after that, the rep’s output will go down. So that’s where there’s a strategy and there’s rest ratios that will be involved with the work that you’re doing.

Maybe you’re just starting out and you just had your surgery and you’re a week out, two weeks out, you name it, pretty early on, and this is a pretty safe bet here. Obviously, you want to check with whoever you’re working with, to make sure that this is a good fit. But there are always different options to be able to substitute or modify something, to make sure it’s safe while still getting a good outcome from it. But this is going to be, let’s say you choose four movements or machines, maybe it’s a combo of the two and you have a 30- to 60-second work time, which is easy to moderate intensity. And then you rest for 30 seconds between, and then you move on to the next one, and you do that three to four times. This could be something that you can accomplish for about 20 minutes. And this could be something where you add in, maybe it’s a bike, and you prop up the ACL leg and you go for about 30 or 45 seconds. You get off and then you transition to the next thing, which could be battle ropes. And then you get off, you rest, you switch, and then you transition towards maybe a med ball slam.

And then for your fourth movement, it would be a SkiErg where you’re seated and you’re just using your arms and making sure that you are offloading the knee and the legs and not putting stress there. But you’re still getting a good workout. You have four movements that you can still get the heart rate up, be able to get a sweat, feel like an athlete, work on your aerobic base as you’re starting out with ACL rehab, and then you build from there. 

And remember, the whole goal is to help balance this whole return to running process early in ACL rehab. And still get your conditioning and your cardio in. And the other means to this is hopefully that you’re training and the sessions that you’re doing with your strength, depending on how that’s strategized. A lot of my athletes still get conditioning from that because we do a lot of super settings and depending on if they’re doing a strength movement versus an accessory movement. I want them to kind of move through it. And it should be strategized to a point where their heart rate gets up with that, as well.

There are different options and different means to be able to get good conditioning, get good aerobic benefits, get good anaerobic benefits, and still keep that up while you’re early in this process without feeling the need to have to go out and run, to get that cardio or to feel like you need to get that sweat or to get back in shape. There are other ways to do it to build it back up. And it will always be specific to each athlete in terms of what they need to be doing, where they’re at, the phase, some of their limitations, maybe. This is where the coach that you’re working with will be so important to be able to help program this for you and strategize it and take out some of his guesswork while you could still continue to train and feel like an athlete. 

I’ll leave you this as we finish up the episode. If you are someone who is working towards running, you are in the early phases of ACL rehab, then I urge you to think about the goal behind the running and the buildup of it. And I want you to think more in terms of, “Okay, this is how I’m going to build up my knee’s tolerance to the load.” Getting it used to those forces, the positions, things of that nature and hopefully you’re getting running mechanics in different interventions to be able to prep you for that. But if the goal is to get conditioning if it’s to get that sweat going, work other ways to do this via this off-feet conditioning or through your workouts. There’s so many different options to do that. But don’t use your initial return to running as the source of your conditioning because what can happen is that we push too much or we fail to balance the recovery and stress aspects.

And let’s just face it, whenever we introduce running in ACL rehab, the knee just doesn’t always like it. And so then that’s where we need to be sensitive and respectful of our knee and the load itself. And if we view the goal as loading rather than conditioning, it will make a drastic difference in being able to progress and to be able to build up your running. This needs to be strategic, just like the entire ACL rehab process—go and figure.

All right, guys, that’s going to be it for today. Early options for conditioning, getting that sweat that you want early in ACL rehab. Thanks so much for listening. This is your host, Ravi Patel, signing off..