Exercise leads to bone growth. That's an irrefutable fact of biology and one of the most important tools for preventing and reversing osteoporosis. While we can observe that this is true– and scientists have been observing it for generations– the mechanisms by which this incredible process occurs are still being discovered.
Today we'll look at a brand new study that digs deep into the question of how new bone is created as a result of the pressure that we exert on our bones when we exercise.
Get ready to zoom way in to the microscopic cells that are responsible for building bone. What you’ll learn there can help you make choices that maximize your bone growth and ensure your strength and well-being.
What We Know About Bone Formation
We know that exercise stimulates bone formation. Surgeon and anatomist Julian Wolff observed this law of biology in the late 19th century, which is why we call it Wolff's Law. That law observes that in a healthy person or animal, bone will adapt to the loads under which it is placed.
We call that load mechanical load. Mechanical load describes the pressure that our muscles exert on our bones to create movement or resist pressure. Weight-bearing exercise places a mechanical load on your bones.
Bones sense this pressure with the help of osteocytes, the most abundant bone cells in the adult skeleton. Found in mineralized bone matrix,osteocytes are mechanosensitive, meaning they are sensitive to mechanical pressure.1
When osteocytes sense pressure, they respond by releasing compounds called paracrine factors, which interact with stem/stromal cells in bone. These cells are progenitor cells with the ability to mature into cells with different functions. The paracrine factors send a message to the stem/stromal cells to develop into cells that will create new bone mass, like osteoblasts. This bone-creating process is called osteogenesis.1
The process described above is how exercise results in new bone growth. We could also break it down into a chain of communication that looks like this:
- You do weight-bearing exercise, which engages your muscles
- Your osteocytes sense the pressure that your muscles are exerting on your bones
- Your osteocytes respond by releasing paracrine factors
- The paracrine factors signal stem/stromal cells to become cells that create new bone
- Osteogenesis begins at the site of the pressure
Synopsis
New bone is formed in response to the pressure that muscle places on bone. This occurs because osteocytes sense mechanical pressure, then release compounds called paracrine factors that signal progenitor cells to become bone-forming cells that carry out the process of osteogenesis, which is the creation of new bone.
Study Reveals The Mechanism Of Communication
Although the chain of events described above is well known, scientists were less certain of how each event in the chain connected to the next one. That's what a team of Irish scientists set out to discover.
They performed an experiment in which they applied mechanical pressure to osteocytes in a lab and observed the results.
They found that when the osteocytes secrete paracrine factors, those compounds use extracellular vesicles to interact with stem/stromal progenitor cells, driving them to the process of osteogenesis. These extracellular vesicles are activated by this osteocyte response to mechanical pressure and are a previously unconfirmed part of the bone formation process.1
Extracellular vesicles are not pathways that are continually present. They are created by osteocytes along with the paracrine factors so that those factors can reach the stem/stromal cells that will then develop into cells that can conduct osteogenesis.1
This remarkable ability of osteocytes to both create the signal for osteogenesis to commence, and to create the means of sending that signal is a major step forward in understanding how exercise creates new bone.
Synopsis
A group of Irish scientists observed what happens when osteocytes experience mechanical load. They discovered that not only do those osteocytes secrete paracrine factors, but they also create extracellular vesicles that allow for the signals contained in those factors to reach the progenitor cells that will begin the process of osteogenesis.
What This Means To You
Every time you go for a walk, lift a bag of groceries, or perform an exercise routine, you're engaging an intricate and ancient system of building bone. It's a solution to bone loss that lives inside of us, the complexity of which is still being discovered by scientists at the top of their field.
You have the power to engage this process anytime you want. Use that power. Activate the bone-building pathways, the osteocytes, the extracellular vesicles, and set them to their purpose: building strong and healthy new bone.
References
1 https://stemcellsjournals.onlinelibrary.wiley.com/doi/10.1002/sctm.19-0405
vivian back in may i purchased the exersise and i have never have been able to get it i was charged for it please help me bea
Bea, please check your email inbox within the next 24 to 48 hours. We are delighted to help you!
Is there a relationship between the amount of the loading and the amount of osteocyte response to mechanical pressure? For example, would a heavy strength routine in the gym result in more bone production than a cardio routine of the same duration, involving the same muscle groups?
Glenn, based on Wolff’s Law of Bone Formation, which states that bone responds to applied force from muscle and gravity by increasing strength and density, heavier weights could lead to enhanced results.
I have been fighting osteoporosis for years due to undiagnosed celiac disease for decades, resulting in malabsorption of nutrients. I have been gluten free for 12 years now and vegan for 3 years. I have been on Forteo for 2 years, followed by 2 years of Prolia injections every 6 months. I HATE taking any of these drugs but once I finished the Forteo, my endocrinologist said I risk rebound fracture of the spine if I don’t follow it up with a bisphosphonate or Prolia. So I chose 2 years of Prolia. I get terrible GI distress for 2-3 months after each 6 month injection. So, again, not absorbing nutrients, leading to more bone loss- maybe activating my celiac immune response?? Now, she tells me that I cannot stop that drug without sealing the bone with an injection of Reclast, which is a bisphoshonate. I am tired of being led down the rabbit hole and wish I never started any of these bone drugs!! Another doctor suggested going on 18 months of Tymlos instead, which claims to stimulate osteoblast production. anyone out have experience with Tymlos?? Thank you!
Indeed, as explained in this year’s March Bulletin, after the discontinuation of Prolia (denosumab), there is an increased risk of suffering a vertebral fracture, cerebrovascular disease, and renal disease.
You can read it here:
https://saveourbones.com/breakthrough-study-shows-how-weight-bearing-exercise-spurs-new-bone-growth/#comments
And this article will provide you with lots of information on Tymlos:
https://saveourbones.com/the-truth-about-tymlos-abaloparatide-the-newest-osteoporosis-drug/
Transitioning from Prolia to a drug-free approach to osteoporosis is a challenge, and I hope you’ll choose that option and that you’ll do well!
There are centers called bioDensity and Osteostrong that claim to increase bone density in minutes per week based on Wolfe’s principal of compressive loads. Not sure if valid but I have been researching these clinics…
All my PT’s say that bone loss is very very hard to reverse with resistance excersize unles the program is relentless and using weights over 200 lbs.Then there can be some minimal bone hardening effects???!!!
Based on the now proven Woolff’s Law, so long as you’re strengthening your muscles, you can reverse bone loss with just about any form of exercise. Take a look at this article that expands further on the topic:
https://saveourbones.com/new-studies-bring-good-and-bad-news-about-exercise/
I am so grateful to you all for your detailed info. I recently purchased the osteo cleanse I am in my 77th year, not a whiz with online. It appears that there is a paper
copy. How could I get one? again I am so thankful for your info.
Karen, thanks for being a member of the Saver community! OsteoCleanse is only available online, but you can download it and print it to have it on paper. Let us know if you need further assistance. We’re happy to help you!
How can a post menopausal woman who is a paraplegic exercise enough to build bone?
Susan, please check your email inbox within the next 24 to 48 hours for an answer to your question. We’re delighted to help you!
I was so glad to read this article on exercise and bone building. I got right up and did my exercises instead of taking a nap. Thank you.
It makes me happy to know that today’s article has motivated you to exercise for your bones and your health, Marcy!
I’m thankful to be reminded of how important it is for us to exercise for our bones. I was diagnosed with osteoporosis 5 years ago, and I try to keep active. But I get lazy sometimes so I’ll print this article and will read it when I’m not in the mood to work out.
Good idea, Patricia! I hope this will help you to follow a regular exercise routine 🙂
Very informative article. Thank you Vivian!
You’re welcome, Mary!
I would love to be able to exercise often but I get many aches and pains all over my body. My doctor said I don’t have fibromyalgia, though. So now I just go out for walks hoping it will hepl my bones. Any suggestions, Vivian?
I’m sorry about that, Pearl! Walking is a bone-healthy weight-bearing activity, but I suggest you make an appointment with a physical therapist to get to the bottom of your issue with pain. Let us know of your progress!
I really enjoyed reading this article, Vivian. It makes me want to exercise every day! Your research is really appreciated 🙂 Thank you.
It makes me happy to know that you’ll put the information in today’s article to good use, Frieda!