Sacral stress fracture - how long?

I should add I’ve been core work and lots of hip/butt strength. I also have been taking vitamin D3 and magnesium glycinate.

Healing times come with a distribution, so relying on anecdotal numbers too much can cause harm. You are doing the right thing by starting with run-walking, but would be safer being much more conservative like: 25% running in the first week; 50% in the second; 75% in the third; and 100% in the fourth, all with low mileage, and increasing run frequency gradually as well from say twice a week to 3-5 times or whatever your normal frequency was. You might well feel some mild or phantom pain for a several months, but any action that doesn’t hurt is okay to do conservatively, even if you can reproduce the pain by lying on it, but need to make sure that that pain trigger doesn’t worsen and cut back aggressively if it does.

The above is assuming you had a stress fracture with a visible line on the MRI (grade 4). You can be more aggressive using pain as a guide with stress reactions (grade 3 or lower).

I have had the following stress fractures in this order:

- Pelvis (left side)

-4th Metatarsal (right foot)

-Pelvis (right side)

-Pelvis (right side)

-Sacrum (left side)

-Calcaneus (right foot)

-Tibia (right leg)

-Tibia (left leg)

They've varied in severity and pain level; only the first 2 showed up on x-rays, while the others were only detectable in an MRI. The sacral fracture was actually the least painful - I didn't feel any pain running but only discovered I had it when I got the MRI for the fracture in my pelvis, which was very painful. Occasionally I felt it cross training on a bike though.

Anyway, in my experience, 6 weeks has been enough recovery time for all my stress fractures besides the pelvic ones. Even once a fracture is fully heeled, you might still feel some pain from tightness, scar tissue, and new nerves that developed in the heeling process. You should be ready to start running, but use pain as a guide. If you feel consistent or worsening pain in the same spot, you should stop running and rest at least 2 more weeks. If you feel no pain running that's a great sign. If you feel random, changing and sporadic pain, that's not necessarily a bad sign, as long as it doesn't get worse or become constant.

Another note - I don't know what your training volume was before the injury, but it sounds like you've been cross training and doing PT. In that case, you're probably still pretty fit, and in my opinion, walk-runs aren't really necessary. I would recommend starting with 30 minutes of easy running per day in the first week, 45 in the second, up to 60 in the third, up to 75 in the fourth, as long as you feel mostly comfortable on your runs. Definitely don't push the pace though. After 5 or 6 weeks, you can start adding intensity, but don't up your mileage at the same time.

Good luck with your recovery!

Thanks, guys! Both helpful responses and good advice. I’m not exactly sure how I’m going to return yet, but I’m leaning towards the first poster’s plan, because I would rather be that conservative than come back quicker and possibly get reinjured. I’ve never had a stress fracture until this one, so I don’t know what works for me on returning to running.

Does anyone else have any return to run plans? Any experiences with certain plans? I’m still not sure how I’m going to do this and how fast I can return.

I wouldn't risk it at all especially if it is still tender. That's still a stress reaction or fracture. If you run and have to stop again it's a waste of 6 weeks.

I am 5 months out from a sacral stress fracture and cannot run yet. Too much pain. I am able to walk but even that is not pain free. This injury is horrendous.

Chances are even when the fracture is healed you will still have some pain and soreness because you need to work with a PT and figure out how to strengthen and get the right muscles going when you run. Also, really make sure you’re eating enough of the right foods

When I had sacral stress fx, resting will let it heal but chances are there are some root causes to address while it’s healing and beyond that like keeping the back flexible enough, fixing super tight back and back muscles, Glutes not firing, tight adductors, an inability to properly squat with any weight whatsoever, not eating enough to support the training volume

How did your return to run go?

Did your glute ache at all while returning? But no sharp pains, or pain in the lower back?

im almost six weeks out of sacral sfx. Mine was also pretty mild. I’ve been pain free and walking now for a couple weeks. I did trying a 5x 1:00 on, 1:00 off and now I just feel like I irritated it. It doesn’t feel painful just irritated and mostly in my upper glute.

To follow up my sacral stress fracture took 1.5 years. Now I can run again. It was very painful despite rest. For very long.

would love to hear more. Was any kind of rest, or cross training, or PT exercise, or strengthening helpful in that year and a half? I'm at 8 months and it's no fun.

How was your return to run (if any..) ?

I wouldn't risk any running (even recovery runs) until another MRI confirmed complete healing of the injury. Bones take way more time to heal than muscle, and it can be painful even while sleeping.

And indeed it's an horrible injury and I hope you all will heal quickly.I went from a 68min HM guy to a guy walking painfully for weeks.

Got it at the end of October 2024. I had been having a small buttock and foot pain since a few days, continued running easily, then suddenly after a 1 hour easy workout and climbing some stairs, I could barely walk 3km back (took 45mins with heavy limping) home due to a big sharp pain in my lower back+buttock, the next two/three weeks I was lying in bed and ambulating with big pain for necessary daily tasks.

Hop test (painful on affected side) and MRI in mid-december confirmed heavy sacral stress facture on right side with big oedema. Haven't been running or cycling since around 2 months and it still hurts a bit walking, so definitely not close to running (or even cycling) again.

I'm considering doing more cycling instead of running to avoid future injuries like this. It's no fun/painful and can sideline you for months.

6 weeks is still early in the recovery (though not the beginning) for a sacral stress fracture. They generally takes 12-14 weeks to fully heal because it's hard to completely unload the sacrum unless you stay in bed the whole day. At 6-8 weeks, I could easily pass the hop test and walk/cycle pain free for hours, but the follow-up MRI at 7 weeks showed I still had an oedema (but no visible line left) so be careful.

If you are at this stage, I wouldn't risk running and would cross-train swimming/steady cycling another 6 weeks, before starting a return-to-run program. Prolonged pain free walking means that indeed your bone has already healed pretty much, but remember that running is 2-3 times as much stress on your bone than walking. Take your time and x-train one or two months more. It won't bring your fitness to crap and you will do yourself a big favor avoiding another stress fracture.

2 years

This is why you shouldn't run 6 or 7 days a week. No time for recovery.

Agree with the post above, you need to know why the fracture happened and take the steps to prevent any reocurrence. . It's not just healing the bone then redo the same mistakes which led to the fracture, or you may end up in a bad cycle again.

Mine happened because I was running every day with almost no recovery days. Now I no longer run every day and included a lot of cross-training in my schedule. This injury is very painful in the first weeks and slow to heal. So I no longer want to live through this.

8 weeks ish is reasonable to return to running. Remeber, if you do the "return to running protocol" where you are alternating running and walking etc...that adds another 3-4 weeks before you are running close to 100%. So thats relative rest as well.

Ignore this poster. He thinks those with mickey mouse degrees are intelligent.

Tender when lying on the area : definitely not healed. Non impact cross-training and rest 4-6 more weeks, then reevaluate to check if ready to start running. Cut back agressively on running a few more weeks if any small sacral ache happens and last more than a few hours after running.

Bone injury : zero pain tolerable during rehab, no brainer here. Its not like soft tissue injuries for which you can accept mild pain.