Rehabbing a Muscle Belly Injury

My Spin on the Starr Rehab Protocol

Almost everyone, whether they train or not, will eventually pull a muscle or a get a tweak. We have a great tried and tested protocol to use that speeds healing, when that tweak is muscular. But understanding a little bit of background info is needed to apply this protocol correctly, and to appreciate it fully.

This article was adapted from a Twitter/X thread I wrote yesterday, fleshed out a little more fully (and with the ability to correct a few typos) here.

Muscle vs Joint Injuries

To understand the Starr Rehab Protocol (SRP), you need to understand the difference between a muscle and a joint injury. Slightly oversimplified but good enough for our purposes here: When it comes to muscular injuries, you MAKE them heal; when it comes to joint injuries, you LET them heal. This is not absolutely always the case, and not absolutely binary as laid out, but it works well enough as a first approximation for our purposes here.

One big reason for this is that muscles get tons of blood flow - they are highly vascularized - and thus respond more to the stress we place upon them. Joints, bones, tendons, and ligaments are not highly vascularized - they do not get much blood flow. This is a large part of why muscles change more in response to training than ligaments and bones do. Just as muscles respond more to training in the traditional sense of growth, so too do they respond more and quicker when it comes to healing via rehab. Of course bones do get denser and tendons thicken up in response to training, but the changes aren’t as profound as we see in muscle tissue growth. Similar to healing, they do have healing capacity but it isn’t as quick as muscles’ and usually the active rehab process can’t start as quickly as after a muscle strain. Bill Starr figured out how we can use this bit of physiology to our advantage, to actively heal muscles even quicker.

The veins you see running through the muscles of a lean person aren’t just for show - they deliver blood bearing oxygen and nutrients to the cells

The Legendary Bill Starr

The Starr Rehab Protocol is named after legendary lifter and strength coach Bill Starr. Bill Starr was a competitive lifter back in the 1960s at York Barbell. While there, he served as the editor of Strength & Health, the nation's most influential fitness magazine at the time. He was possibly the first professionally employed Strength and Conditioning coach, spending time working for the NFL’s Baltimore Colts and later for the University of Hawaii. Eventually he came back to the northeast and was the strength coach for Johns Hopkins University until 2003. He has several well known books including his classic The Strongest Shall Survive, and much of his writing can still be found online in several different places.

Here’s a couple classic pictures of Starr in his lifter days.

The Protocol

The SRP was brought to public light by Mark Rippetoe, his clearest early treatment of it in this video from 2015. In short, it goes as follows: After you get a small muscle tear such as a strain, rest 1-3 days to make sure all internal bleeding has ceased (don’t stretch it during this period!), then begin to do very high rep, low weight work on the muscle to heal it up. For larger but still non-surgical tears you might need to rest slightly longer before starting the protocol, and you may also need to start with easier, more regressed movements, but the same idea applies: As soon as you can start moving it again without exacerbating the initial pull, DO SO. This accelerates the healing process big time compared to just rest.

The key is not to do more than it can handle, too soon. So don’t load up on weight. Instead, use higher rep, lower weight work to pump blood into the area, which you’ll recall from above is a big part of what promotes healing. This also helps the muscle tissue heal healthily, instead of with scar tissue, which is prone to re-tearing later on. This is also why it’s crucial not to wait 3 months before doing this. After a short amount of time, a few days for a minor strain, a little more for a serious but sub-surgical pull, the muscle will start to heal with scar tissue if you don’t start moving it, and we don’t want that. If the muscle is forced to contract in the process of its healing, it will generally heal as normal muscle tissue rather than a scar.

The weight to start with is a weight at which you can use absolutely perfect form, as this forces the injured area to get worked to its full capacity within the context in which it normally functions. This will vary person to person and injury to injury, but we’ll use an example where the person can start back with the empty bar for squats, to keep things simple. But this won’t always be the case.

Our example will be a healthy person who was previously squatting well with no problem, was working with 275 for tough but sub-maximal volume sets of 5, who gets a small hamstring pull. It’s definitely pulled, but isn’t a tear off the bone that requires surgery, or even a severe tear. But it’s definitely pulled. After 1-3 days rest, he will probably be able to start right off with empty bar squats. But instead of adding weight each set like he’d usually do until getting to work set weight, the SRP has you just do 3 sets of 25 and pump lots of blood to the area.

You want to use a just below parallel, low bar squat for these, just as you do for your main variation of the lift in general. But if the low bar squat cannot be performed for some reason, other variations like high bar or safety bar work too.

You can do this protocol daily at first, since the weight isn’t systemically stressful and the muscle tissue heals and remodels quickly. As the weight gets heavier, you’ll start to rest a day between workouts like you normally would. So the first week, maybe you do 6 days which look something like this:

Day 1: 3 sets of 25 at 45 lbs

Day 2: 3 sets of 25 at 55

Day 3: 3 sets of 25 at 65

Day 4: Off

Day 5: 3 sets of 25 at 45, 65, 85

Day 6: 3 sets of 25 at 55, 85, 100

Day 7: 3 sets of 25 at 65, 95, 115

And so on. Usually the more you do it, the more the thing heals, and the quicker you can add more weight. This is why the weight jumps got bigger as the week went on. However, keep in mind this is just an example and sometimes things go slow at first, and it sometimes takes a little longer til you can speed up the process.

Eventually the weight gets too heavy to do for 25s, so as the weight goes up, you bring the reps down to 20 then 15 then 12 or 10, and so on, while adding bridging sets so you don’t have to make absurdly large weight jumps from set to set.

This protocol works extremely well. The one big problem: Sets of 25 are miserable.

My Spin on the Starr Protocol

In short: Use more sets of 10 instead of fewer sets of 25. I’ve used the 25s many times with myself and clients, and having done this way as well, I haven’t found any disadvantage. Instead of 25s, do 7 or 8 sets of 10. For the 115x25 example day day above, it’ll look something like this: 45x10, 75x10, 95x10, 115x10x5. You won’t need much rest, so while 8x10 will take a bit longer than the 3x25, it won’t be much longer, and you’ll have far less misery. You also won’t be breathless, so can superset with upper body if you want to save time, and you might even end up spending less overall time this way than if you did 25s.

You also get 50 total reps at the highest new weight, which is the one that promotes the most healing, since you’ve already adapted to the lower weights on previous days.

Keep adding weight as appropriate, and often it only takes 2-3 weeks to get back to where you were (though don’t force it, especially if it was a bad tear). By the time you get to where 10 reps are actually challenging, you’ll basically be healed and can quickly jump back to heavier 1-5 rep sets over just a few short re-adjustment workouts of 8 and maybe 6 reps, then back to fives.

Another benefit I’ve found, aside from avoiding the misery of 25s: most people feel like they’re “failing” when they have to go down from 25 to 20 to 15 to 10 reps as the weight goes up. So instead of adding more weight quickly, which is the primary goal, they get fixated on “I have to do 25 reps” and they spin their wheels adding only 5lbs at a time when they could be adding 10, 20, or even more pounds per workout, no problem. Sets of ten solve that.

Closing Comments

I’m rehabbing my shoulder right now this way and it’s working brilliantly, as it has every time I’ve used it either myself or with clients - probably hundreds of times by across thousands of people I’ve coached over the years, for the many tweaks and pulls that are inevitable in life, whether you train or not.

BUT REMEMBER: This is for muscles, not for joint injuries!

While physical therapy and active rehab can help heal some joint issues, it’s not always so clear cut. Don’t throw high volume work at a joint injury without consulting a professional first. And don’t throw more than you can handle at a muscle pull either: if in doubt, start easier - either lower weight, an easier movement pattern (like unweighted hamstring curls or partial squats, if you can’t do more after a few days to let it stop bleeding internally).

Bill Starr passed away in 2015, but his legacy lives on. I merely stand on the shoulders of a giant, tweaking his brilliant protocol slightly, so it’s just as effective but a little less miserable, and possibly even more effective when you consider the psychological reluctance to drop reps as the weight needs to go up to continue the rehab process.

Give it a try next time you have a muscle belly injury and see how it works for you.