One of the most essential parts of ACL rehabilitation is regaining strength in the leg. Traditionally, rehab specialists have been guilty of underloading people during the rehabilitation of these injuries.
Ah, the old “3 sets of 10.”
In this episode, we review a recent journal article that compares the outcomes of two different set and rep schemes during ACL rehabilitation.
To view more episodes, subscribe, and ask your questions, go to mikereinold.com/askmikereinold.
#AskMikeReinold Episode 371: Periodization of Strength Training After ACL Reconstruction
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Show Notes
• Resistance training with linear periodization is superior to the ‘3×10 reps protocol’ after anterior cruciate ligament reconstruction: a randomized controlled trial
• Evaluation and Treatment of the Knee online course
Transcript
Mike Reinold:
Welcome back everybody to the latest episode of the Ask Mike Reinold Show. We’re here up at Champion PT and Performance up in Boston, Massachusetts. We’re here today. We have a journal article review for you. I’ve actually gotten some emails and some DMs from some people. We still want to hear it. Are you liking the journal article format that we’re doing? Are you missing the questions?
We’re kind of going back and forth a little bit, trying to do it all, but definitely want to hear some feedback, if you like these journal article reviews. We’re enjoying them, but if you aren’t, we’ll pivot, so just let us know. But today we have a nice journal article. Oh wait. I didn’t introduce you guys. Let’s see. We have Kevin Coughlin, Lisa Lowe, Lenny Macrina, Mike Scaduto, Brendan Gates, Dave Tilley, and Anthony Videtto here for you with this great journal article review.
The one we’re going to start with, the one we have for today was pretty cool. So let me see here. We have a study from, it’s out of Brazil, from Physical Therapy Journal in Sport from May, 2025. And the title of the article is “Resistance training with linear periodization is superior to the ‘3×10 reps protocol’ after ACL reconstruction: a randomized controlled trial.” So we were excited when we saw this come out and wanted to definitely dig in and go through this with you. So Anthony, you want to take the lead and tell us what they did in the study?
Anthony Videtto:
Yeah. So pretty interesting study. I’ll take a look at the methods and who they were looking at here first, and then we’ll kind of go into what they found. So looking at the subjects in this study, they were males, age range from 18 to 40, who underwent ACL reconstruction with hamstring graphs. No other graphs were included. So I think Lenny’s already out on this study, probably, but we’ll have to hear from him later.
So, the first three months of rehab were standardized for both groups. The first month, first four to five weeks, they said focus on the basics, managing swelling, regaining extension, normalizing gait, activating the quad, all that good stuff. Then the next two months, they started to incorporate some newer things. They started adding balance and proprioception exercises, added core exercises, and then they started introducing strength exercises, including a mini squat, which progressed to a goblet squat and then lunges, single-leg knee extensions, things of that nature.
So that was kind of the progression for the first three months. Every person in the study was doing the same exact thing. And so what they did at the three-month mark was they tested strength using a handheld dynamometer at 90 degrees of knee flexion. For the linear periodization group, they found that the average LSI was about 80%. And then for the 3×10 group, the average LSI was about 76%. So this is where they broke individuals up randomly into two groups. One group was a linear periodization group, and then one group was a 3×10 group. There were 22 participants total in this study. And so for those 12 weeks, the linear periodization group went through a progression, and it changed every four weeks. For the first four weeks it was 3×15. That was their set and rep scheme.
Then it progressed to 3×10 and then finally got to 3×5. And then for the other group, 3×10, they followed the same set and rep scheme for the whole duration of the 12 weeks. By the end of it, the total volume was equivalent, so that’s how they standardized how much they were working. That accumulated to about 720 reps per exercise. And then the exercises were also standard for each group, including back squats, lunges, and leg extensions as well. And the way that they progressed the other patients was using reps in reserve, which I thought was great. So every time they were doing an exercise, they asked the patient, “How many more could you do?” If that number was two or more, they would progress the load. And that’s how they got that kind of progressive overload to modify for intensity.
So after the 12 weeks, they then did another strength assessment at 90 degrees of knee flexion, with the handheld dynamometer, and they found that the linear periodization group, their average LSI was about 97%, and the 3×10 group only increased to about an 85% LSI. So they found that that was statistically significant in favor of the linear periodization group. And then they also used two other objective measures. They used the ACL-RSI questionnaire, and they found that the linear periodization group scored higher than the 3×10 group. They were more ready to return to sport at that point. And then they did compare some horizontal and vertical hop tests for each group, and they found that the horizontal hops seemed to be pretty symmetrical for each group, but both groups remained limited in vertical hop testing.
They were doing some plyometrics throughout this three-month progression as well. But, as we know, it’s pretty hard to get those vertical hops back after ACL surgery. So those are the kind of conclusions. Seems like linear periodization was superior in terms of getting LSI back at about six months after surgery.
Mike Reinold:
This is one of those articles that I think we were all excited to see and then excited to read and see the results, because I think a lot of people preach this. They talk about this on the internet, that you have to advance your strengthening protocols and you have to change up the set rep schemes and stuff like that. So I think it was really good to see this, and I think this will be a very good paper, hopefully, in the future for people to reference as why they do certain methodology with their strength. But I want to hear from you guys. What were some of your thoughts on the article? Good? Bad? What are you going to do different? Kev, you want to start?
Kevin Coughlin:
Yeah. Anthony and I were talking about this a little bit last night, but one thing that I thought was interesting is that the 3×10 group still ended up progressing pretty well. By the end of the study, they had 85% LSI, and I think that speaks to the fact that the authors use the reps in reserve to monitor intensity.
So for me, that’s a big takeaway. And I think other people who listen to this or read this study should take that away as well, is we want to make sure that we’re constantly pushing intensity and asking our patients how the exercise feels. Because I think far too often we stick with the same load, even if we’re changing the set and rep scheme a little bit, and we’re not always checking in and trying to figure out, “What intensity was this?”
And I think there have been some studies out there that looked at how reps in reserve correlate with your percentage of one rep max type thing. So, I think what they said was having two reps in reserve is kind of a good cutoff when you’re really trying to build strength. So that’s something I would take away, is even if you’re not mirroring, changing the volume over time, which we should be doing according to this study, and I think other principles of strength and conditioning that we know, we definitely want to ask about intensity and make sure that we’re progressing weights. So I thought that was pretty cool.
Mike Reinold:
Yeah. You know what, I thought about that, Kevin, when I was reading it. I thought it was kind of interesting because I still say I think this a lot. With an untrained individual, you can linear load their weight to the resistance for a very long time and make a ton of gains. And I actually think this study showed that. But what it did show is that if you manipulated the set rep scheme for lower reps, they were able to load more. One of the most exciting parts of this study for me was the graphs. I don’t know if you guys picked up on this. The graphs of loading.
And not their strength gains, but their loading. You could see they both… They load well, but the loading went up so much higher in the group that decreased their reps, it really opened my eyes that you have to challenge these people. And sometimes even with best intent of trying to have some reps in reserve and make that consistent, you still have to lower the set rep schemes and increase the load for it to be as effective. That was a huge eye opener for me. So I agree with you on that one, Kevin. Who else? Dave, yeah, what do you think, Dave?
Dave Tilley:
Yeah. I’ll just go quick. I think obviously for a lot of us who have a strength conditioning background, I think that’s one of the things that we notice is commonly maybe missing in some of these studies, is the ability to really use solid strength conditioning principles. So it was great to see this kind of involved and you kind of take that to all your rehab type stuff. But the thing that I appreciate is, I like that you used hop testing in both vectors, vertical and horizontal, as Anthony said, but for me, it really summarized how you have to even have more of a strength conditioning hat on because, yes, if you work on three months of the early stuff and it’s great, then you just hammer strength for whatever time period you have, but you then don’t really get somebody into the plyo strength kind of like rate of force development bucket, it’s not shocking that their jump testing is not going to be, for both groups, it’s not going to be statistically crazy different side to side.
Versus when you get a little bit more further out, say if it’s like four and a half or whatever your LSI is doing pretty well, you really need to kind of then shift gears to, okay, the strength has to continue, but what am I doing for power and what am I doing for rate of force development and what am I doing for some sort of tolerance to loading, because half of that is probably another new stimulus for strength conditioning obviously, but also it’s confidence. Hopping is very much also a indicator of, “Do I feel comfortable jumping on two legs equally?” And so, I think ACL rehab, as we’ll probably talk about in a couple articles, is very long and there’s a lot of different things that have to change.
And I think personally, for me, I find myself, when I have a surgery, I’m kind of more in the strength conditioning hat than I am the PT hat after maybe three months. I find myself talking to strength coaches more like what are you doing, what do we think we should do, because it’s tissue tolerance, of course, but the principles of developing the next athletic quality symmetrically is important, symmetrical power, symmetrical speed, so like that. So I appreciate they use hop testing, but it really big step back for me was like, okay, strength bucket sometimes more so than just the PT bucket.
Mike Reinold:
Awesome. Mike, what do you think?
Mike Scaduto:
Yeah. I’m going to challenge Lenny I think a little bit here. I think anyone who listens to the podcast knows that Lenny’s a patellar tendon graft guy, so they excluded patellar tendon grafts from the study. At six months, the linear periodization group had a 97% LSI. How common is that in patellar tendon, perhaps?
Mike Reinold:
Len’s going to say the other side’s weak, but go ahead.
Lenny Macrina:
I was waiting to chime in. I was letting everybody speak, and then I was going to, I mean, A, they only went out to six months out of surgery, and they only included hamstring grafts, which we know are biased in that hamstrings quickly weaken and don’t regenerate. You get a little pseudo hamstring, that tendon that grows back, and it may never grow back. The long-term hamstring issues are potential. So yeah, at six months out and 90-plus percent LSI, I’m going to say it’s probably not… Very rarely do we see that. So some of their methods are questionable, and their inclusion/exclusion criteria. I appreciate what the authors did. Any time somebody publishes papers like this, there’s a lot of work that goes into this. We’ve lived it a bunch.
So kudos to them for doing this and putting this out there and helping us understand strength and conditioning principles. I use these concepts every day with my ACLs, but I primarily treat patellar tendon autografts. So to extrapolate the paper to other than hamstring grafts, I think you can’t just by the laws of research. This is all hamstring autografts. And there was some meniscal injuries involved in the paper and all that, but I would be cautious in extrapolating. I think the concepts of strength and conditioning principles are valid, and so we use that all the time.
Mike Reinold:
You can’t extrapolate this at all, like 0% extrapolation. I don’t know if there’s a scale of extrapolation. That’s a fun word.
Lenny Macrina:
I mean, I appreciate the paper for what it is. There were only, what, 22 participants? I mean, the power is small. It’s hamstrings only. There’s so many different flaws in the paper.
Mike Reinold:
It’s just men, but…
Lenny Macrina:
Correct. Right.
Mike Reinold:
Even though it’s just men. I mean, I think you could still, you can’t say definitively, but I mean you could say a woman is also probably going to get stronger with this periodization…
Lenny Macrina:
Absolutely. But they also, as was mentioned, they also get strong…
Lisa Lowe:
You can’t just…
Lenny Macrina:
…Times 10. Correct.
Mike Reinold:
I mean you can assume, but man you can…
Lisa Lowe:
I think my biggest qualm with this paper, like ACL, like surgeries are done on more women than men, period. There are more ACL injuries in women. So why on earth isn’t this just a study on women?
Lenny Macrina:
And that was…
Lisa Lowe:
If you’re going to do one or the other, pick women.
Lenny Macrina:
…The other same issue with the Kotak paper, the paper that came out that we reviewed a couple months ago…
Lisa Lowe:
In Brazil.
Lenny Macrina:
…Was all men.
Lisa Lowe:
Come on.
Lenny Macrina:
Yeah.
Lisa Lowe:
It’s dumb.
Lenny Macrina:
Yeah.
Lisa Lowe:
Yeah. That was my biggest thing, where I was just like, okay, great. We’ve learned that picking up heavier things makes you more confident and potentially makes you stronger. Wonderful. That’s great. But I feel like the difference of training a female would show within a six-month timeframe. And I think you have to look at that before you could ever think of generalizing a tactic in terms of a strength and conditioning choice. That was my biggest qualm with this, of why on earth we’re just picking men for this paper, if you’re going to pick one gender or the other? I mean, the other side that they found was the linear periodization group had better psychological readiness, which that doesn’t match between female and male ACL rehab. The psychological readiness of a female is not as good as a male going through ACL rehab, so where would those markers be at a six-month mark if this was a study with women?
Mike Reinold:
But again, though, to your point though, Lisa, I actually thought that was a sneaky awesome part of this study. I’m glad you brought it up that RSI was better. So essentially, there was a correlation between quad strength and RSI. That’s awesome. I think that’s amazing. I mean, I don’t want to assume women are also… I mean I still think there’s a correlation between quad strength and RSI depending on gender, but maybe not. I don’t know. Maybe not. You’re right. But Brendan, what do you think?
Brendan Gates:
Yeah. Just real quick. I think hitting on the ACL-RSI, so I mean people are generally familiar with that, but it’s a psychological readiness. It’s essentially telling us, as an outcome measure, how confident the athlete is in their ability to come back to sport. So I think the cutoff is usually around 60, and this paper is 56 points. And I think that when your periodization group scored 67, where the 3x10s were at 53. So I think, again, we can’t extrapolate across all populations, but what I thought was kind of cool is that one of the reasons people like to rehab at Champion is because they’re in the weight room and they’re around all these healthy athletes and they feel like they’re athletes and they’re training.
I think if we take principles of strength and conditioning, like linear periodization, and apply it at the right point in rehab, it makes them feel like they’re training and they’re kind of in that gray area between rehab and training. So it kind of says, “All right, if we treat an athlete and we train them like an athlete with principles of strength conditioning, they’re going to feel more confident to become an athlete again.” So I thought that was kind of a cool takeaway.
Mike Reinold:
Yeah. More confident and stronger.
Lenny Macrina:
Well, but three times 10 with reps and reserve is also effective.
Mike Reinold:
It’s effective…
Lenny Macrina:
In hamstring autografts…
Mike Reinold:
…But not as…
Lenny Macrina:
…Not as effective…
Mike Reinold:
In hamstring autografts in men…
Lenny Macrina:
…In males…
Mike Reinold:
In Brazil. Can we not extrapolate this to America? How’s that? All right. So for patellar tendon grafts, Lenny, are you going three sets of 10 for forever because you…
Lenny Macrina:
Because this paper did not prove to me yet.
Mike Reinold:
I…
Lenny Macrina
Just kidding. Just kidding, people.
Mike Reinold:
I know. I know. You’re supposed to say you can’t extrapolate. Yeah. We’re all excited to see this on more graphs in genders and countries, but I think we’re all excited about the study.
Lenny Macrina:
Yes. Yes.
Mike Reinold:
It’s a pretty good study. Who else? Anybody else have any other comments? Did we miss anything? Because…
Lenny Macrina:
Love it.
Mike Reinold:
…I think that was really cool, but what else? Awesome. All right. You guys, nobody wants to follow up on these extrapolations.
Lenny Macrina:
I think that was a good, yeah.
Mike Reinold:
The extrapolation of extrapolation. I completely agree. I hate — I guess to standardize controls, it makes more sense to do that, but I would much rather see a little bit more diversity in these studies. But still, this is a cool study. I think we can say that this is probably a really good periodization scheme to consider, and I hope we get more research in other demographics and populations, but man, this was really cool and better quad strength, better performance, and a better RSI, less kinesophobia, stuff like that. Win, win, win. I think this is going to be a big article for people to open their eyes that you have to change your set rep schemes with these ACLs in that late phase.
So, awesome article. I think it was really good. We got a link to the article in the show notes that you can check out. I want to hear your thoughts, too. And I kid. I kid. I know. I understand research methodology. I know you can’t extrapolate, but I’m excited to try this in a variety of different populations. How’s that? Is that a good way to handle it? Lisa disagrees. But, no, great stuff.
Please, if you’re liking the format of these, like our journal article reviews, hopefully these are fun for you. We’re enjoying them because it’s keeping us up to date, and we’re talking about these articles in clinics. So maybe if you don’t have mentorship or people around you in your clinic that are eager to learn like this, maybe this is like a pseudo journal club for you too. So let us know your thoughts. We’d love to hear it. Be sure to rate, review, subscribe on all your podcast formats, and we will see you on the next episode.
