• Your life and health are your own responsibility.
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“Walk it off, Sally”: Why Exercise Helps Speed Injury Recovery

Caution: contains SCIENCE

Robert H. Demling, MD. The Role of Anabolic Hormones for Wound Healing in Catabolic States. J Burns Wounds. 2005; 4: e2.

“There is a well-recognized interrelationship between hormones, nutrition, and wound healing. The anabolic process of protein synthesis, with new tissue formation, requires the action of anabolic hormones. Exogenous administration of these agents has been shown to maintain or increase lean body mass as well as directly stimulate the healing process through their anabolic and anticatabolic actions.” [emphasis mine]

Note the word “required.” That is a very strong word in the scientific literature. Anabolic hormones like testosterone*, growth hormone, and IGF-1 are required to synthesize protein…and muscles, tendons, and all your other body tissues are made out of protein. So: in order to repair damage to your tissues, you require the action of anabolic hormones.

* The testosterone situation is complex: it seems to inhibit collagen synthesis while encouraging other types of protein synthesis. However, certain synthetic anabolic steroids seem to encourage collagen synthesis. I may explore this in more detail in the future.

You may also recall that levels of these hormones decrease dramatically as we age, starting around age 25 and beginning a steep plunge around age 40. That is why we heal more slowly as we age.

(Yet, strangely enough, the medical establishment does not routinely prescribe anabolic hormones to people over age 25 who are recovering from injuries. We are told to accept slow and imperfect healing as an inevitable consequence of aging, despite the ready availability of drugs that can fix this problem. Wouldn’t it seem strange if we were told that pain was an inevitable consequence of injury and refused access to Vicodin, or even Tylenol? But that is a different discussion for a different time.)

Moving ahead: in order to speed the process of healing, it is clear that we need to boost our levels of anabolic hormones. Besides adequate sleep and protein intake, the most effective way to do this is…exercise.


Schwarz AJ, Brasel JA, Hintz RL, Mohan S, Cooper DM. Acute effect of brief low- and high-intensity exercise on circulating insulin-like growth factor (IGF) I, II, and IGF-binding protein-3 and its proteolysis in young healthy men. J Clin Endocrinol Metab. 1996 Oct;81(10):3492-7.

“In summary: 1) brief exercise leads to small but significant increases in circulating IGF-I, IGF-II, IGFBP-3, and IGFBP-3 proteolysis; and 2) these responses may be influenced by exercise intensity.” (Small but significant = 8-13% for low intensity exercise, and 13-23% for high-intensity exercise.)

Now, the big one: human growth hormone (hGH).

I prefer to link to studies directly, but this article does such an excellent job of summarizing and linking several studies linking hGH release to exercise frequency and intensity that I’ll just point you here:
Human Growth Hormone: Breaking Down a Few Scientific Studies

Apparently the key here is the intensity of the exercise: just 30 seconds of all-out sprinting increased hGH secretion by 4.5 times, and serum hGH remained elevated for 90-120 minutes afterward! So it seems that, contrary to the bodybuilders’ consensus, you don’t necessarily have to lift heavy weights to cause hGH release (though lifting heavy is certainly an effective way to do so.)

Furthermore, multiple short bursts throughout the day are more effective than a single workout:

Wideman L, Weltman JY, Hartman ML, Veldhuis JD, Weltman A. Growth hormone release during acute and chronic aerobic and resistance exercise: recent findings. Sports Med. 2002;32(15):987-1004.

“Following the increase in GH secretion associated with a bout of aerobic exercise, GH release transiently decreases. As a result, 24-hour integrated GH concentrations are not usually elevated by a single bout of exercise. However, repeated bouts of aerobic exercise within a 24-hour period result in increased 24-hour integrated GH concentrations.

Executive summary: in order to recover as quickly as possible from injuries—particularly as we get older and our natural levels of anabolic hormones decrease—perform multiple short bouts of high-intensity exercise, throughout the day, in whatever form your injury leaves you able to do so.

If you have leg injuries, lift some barbells. If you have arm or back injuries, do sprints on a stationary bike. If you’re confined to a hospital bed, lift some books. Do whatever you can without re-injuring yourself, because you will heal faster and more completely.

Live in freedom, live in beauty.



Permalink: “Walk it off, Sally”: Why Exercise Helps Speed Injury Recovery
  • downtownj

    Succinct and well put. Broke my wrist hooping. Time to start sprinting it seems. Thanks for the great post. Very glad I found this resource.

  • downtownj:

    I've since learned that it's also helpful to take a hot shower, or even hot tub it, after exercise, as it raises hGH levels.  See http://www.ncbi.nlm.nih.gov/pubmed/12713511

    I hope your recovery is quick and complete. Feel free to stick around!


  • Scotlyn

    Very interesting post. The heat link in your comment may show the basis (in terms of clinical observation) for the strong preference TCM practitioners have for applying heat rather than cold to injuries. They often cite the classical teaching that application of cold to an injury will make it chronic and long-lasting, while heat promotes healing, and are generally not too impressed with the I (ice) part of the R.I.C.E. protocol taught in First Aid classes.

  • Scotlyn:

    I agree: RICE is stupid unless you have a muscle hematoma, and even then you only ice until the swelling is no longer critical.

    How is tissue damage supposed to heal without blood flow?  Inflammation is the body's healing response.  Sheesh.

    MEAT is better than RICE (Google it).


  • Kate

    I’ve heard a defense of icing an injury that takes into account the fact that inflammation is a natural healing response. Not very detailed, but it goes like this: the inflammation is step 1 of the body’s healing process, but the body also needs to get to step 2 and onward. In the case of recurring strain or inflammation that lasts longer than optimal (“optimal” seems to depend on the location and severity of the injury), inflammation needs to be controlled because the good intentions of the body will at this point be doing harm by keeping the injured site from progressing to later steps of healing. For example, I sprained my wrist last fall and wouldn’t have needed to ice it if it hadn’t been a very inconvenient sprain which I kept reinjuring for months, doing things like itching my elbow and picking up objects heavier than a few pounds. The inflammation from the recurring injury was supposedly preventing further healing after the initial inflammation had done its job.

    This all makes sense to me. Thoughts, anyone?

  • Kate:

    I think that if you're constantly reinjuring, it's time for the old joke: “Stop doing that, then.”  Braces can be helpful, if only as a reminder not to use that body part!

    There is some merit to the idea of occasional, short-duration icing (15 minutes), as it can temporarily increase blood flow after you take the ice off.  Alternating ice and heat would be even better, but cold is more difficult to work with logistically.  I just tie a heating pad around the affected area while I'm working.


  • Mitchell

    The method I’ve learned is ‘PRINCE’ or
    Protect, Rest, Ice, NSAIDs, Compression, Elevation

    I’ll outline the steps quickly, and maybe that will give you a better idea of why icing a injury is good.

    Protect – prevent further injury

    Rest – stop moving the area and let it rest to reduce swelling.

    Ice : ice causes the tissue to contract, which prevents excess swelling. You only want to do this for a 10-15 minutes every two to three hours for the first 2 days following a strain or sprain.

    NSAIDs – non-steroidal anti-inflammatory drugs, like ibuprofen and aspirin that will stop the pain but also reduce swelling to accelerate healing

    Compression – wrap injury to reduce swelling

    Elevation – lift above heart-level so that excess fluid can drain via gravity, especially useful during sleep when you cannot apply ice yourself.

    Now thats for immediate action over the course of maybe a week after a serious injury.

    Exercise as you’ve mentioned is great for helping an injury along. This is because your pumping new blood into the area (and more of it).

    Heat works along the same lines, the local capillaries naturally expand and enlarge, which lets even more blood into the area.

    The oxygen and nutrient-rich blood is possibly the most necessary ingredient for a speedy recovery.

    Now, you’ve mentioned alternating hot and cold – this is good for a specific reason. You said that taking it off can increase blood flow, and thats true.

    When you alternate, it increases the blood flow even more, and prevents the body getting used to the hot temperature. This ensures that applying the heat is effective, even if you’ve been doing it for a while.

    HOWEVER make sure that your only applying heat AFTER inflammation and swelling has left the area, because otherwise heat will only cause MORE swelling.

    Hopefully this explains the role of icing an injury, and why heat therapy is so great.

    – on another note, great blog, I’ve just started reading your book now!

  • Mitchell:

    That’s a good summary of the traditional treatment.  

    I’m not a fan of compression.  Isn’t icing supposed to prevent the damage done by compression?  (i.e. the swelling prevents blood and lymph from moving through the area)  If so, then why would anyone want to compress the area deliberately?  Again, in the case of a hematoma, I understand: I’m bleeding internally, and I need to control the bleeding.  But in the case of anything else, it seems like compression is causing the very problem we’re trying to prevent by icing.

    Furthermore, swelling usually isn’t a big issue for the injuries we’re most concerned about (tendon/ligament strains, sprains, or snaps).  Yet doctors and therapists alike continue to recommend a treatment that decreases circulation and slows healing in these cases.

    Finally, acute phase inflammation isn’t bad!  It’s a necessary part of the immune response leading to tissue remodeling and eventual recovery.  I have no idea why anyone would want to abort it unless the swelling is cutting off circulation; I have no idea why anyone would want to simulate the cutting off of circulation by compressing and elevating the affected area; and as the acute phase of inflammation lasts perhaps a few days, RICE for a week is far overshooting the mark (and dramatically inhibiting the healing response) even if you still believe it’s necessary to ‘control’ the acute phase.

    Further reading:

    Rice or Meat For Acute Ligament Sprain Treatment?


  • paleodoc

    Applying the RICE principal has more to do with pain relief than accelerating healing. Moreover, it depends on the severity of the injury. An inversion injury to the ankle can result in a minor sprain or joint subluxation or disruption. Resting is more important in the latter than the former. Ice and elevation can help to reduce pain in the injured limb during the first few days after injury, but may not optimize the rate of healing. But I don’t think it retards healing either.

  • paleodoc:

    “Applying the RICE principal has more to do with pain relief than accelerating healing.”

    That's a good point.  There's also some interesting research showing that popping lots of OTC anti-inflammatories substantially inhibits the healing process.

    The best results I've obtained when dealing with my own injuries have been when I skipped RICE and went directly for MEAT.  Maybe I have a greater pain tolerance than others…?


  • […] Hi everyone who stumbles upon this blog. I’m Luke a 15 year old and i work out a lot. I used to work out for football which i was good at, i made varsity this year as a sophomore and started as a defensive tackle. It was going well until i dislocated my shoulder for the 4th time and i have to get surgery which will happen on October 30th. Also the thing that really blows is now i can’t play football anymore. I am going to track my journey of healing which is suppose to take about 6 months for my shoulder to be back to full strength. I am going to try and speed up my recovery time by exercising still but i will only be able to work out my legs. There is a science of reasoning, that i will heal faster if i exercise, if i am working out my legs the simulation of exercise that is happening causes more hormones to be produced which speeds up healing. here is scientific evidence that what i will be doing helps me. ”Anabolic hormones like testosterone*, growth hormone, and IGF-1 are required to synthesize protein…and muscles, tendons, and all your other body tissues are made out of protein. So: in order to repair damage to your tissues, you require the action of anabolic hormones.” I got some information off of this website here is its link, http://www.gnolls.org/191/walk-it-off-sally-why-exercise-helps-speed-injury-recovery/ […]

  • Step

    Both compression and ice work similarly. They both reduce inflammation which retards healing. Body has to get out damage tissue and debre and in return it must get in nutrients and oxygen for repair. Inflammation slows all of that. I have never seen inflammation helping me in any way and don’t know why the body does it. I use compression on all minor injuries with my hands and it does wonders. For example when a hammer feel off a tall ladder on my head it nearly knocked me out but by hard pressure to the bump that was forming till I hardly felt pain and then released the pressure, it hardly hurt and healed very fast. Great for when a kid gets their finger jammed in a closing door, just hold the finger tight till the pain goes away. Ice works as well when applied immediately after the injury. Hot cold water treatment goes back 100’s of years as a time tested way of healing much faster.

  • Step:

    Acute inflammation due to injury (e.g the first few days) is a necessary part of the healing process! It ‘marks’ the damaged tissue and begins to scavenge it so it can be replaced with new, undamaged tissue. Stopping acute inflammation basically short-circuits everything. See, for instance:

    J Physiol. 2007 Jan 1;578(Pt 1):327-36. Epub 2006 Oct 12.
    Macrophages promote muscle membrane repair and muscle fibre growth and regeneration during modified muscle loading in mice in vivo.
    Tidball JG1, Wehling-Henricks M.

    The place compression actually does some good is, as you point out:
    1. A hematoma, where excessive swelling can actually inhibit blood flow, AND
    2. Immediately after the injury.
    After that, you’re just cutting off circulation and thereby retarding the process.

    Pressure vs. pain, OTOH, is simply a distraction, though an often effective one.


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