Our bone density changes as we age.
Having healthy bones is vital to our overall health. One key unique factor about our bones, is that they change in density over time. Bone density peaks when we are fairly young in our 20s and early 30s. Then as we age, our bone density goes down.
Anatomy & Physiology, Connexions Web site. http://cnx.org/content/col11496/1.6/, Jun 19, 2013. – OpenStax
The figure above shows an average representation of bone density changes over time. What it doesn’t show is that some peoples’ curves may drop low enough in density to be considered osteoporosis as they age. Some peoples’ bone densities may decrease more slowly and they may stay out of the threshold considered for osteoporosis.
How do you keep your bones from becoming osteoporotic?
So how do you keep your bones from becoming osteoporotic and what happens when you lose too much bone mass? Unfortunately fractures (broken bones) are something we see in our clinics and in the emergency room all the time. Patients are walking in their house, they accidentally trip over a rug and they have a fracture when they fall. Normally, people would not break a bone just from falling from a standing position, but when someone has osteoporosis, or a low bone mass, then bones are not as strong and they can break very easily. There are about 10.3 million Americans with osteoporosis, and another 43 million that are at risk for it.
Is there any way to decrease your chances for having bone loss?
The short answer is yes!
There are a number of ways to do this including diet, exercise, and even medications, but for this article we are going to focus on exercise! A number of research studies have shown that weight-bearing exercises can help slow bone loss. When you put stress on your bones, like with strength-training, the cells in your bone can detect that stress. When that happens they send signals to other nearby cells that start a cascade of remodeling, that increases the strength of the bone in that area. Remodeling is when the cells in your bones rebuild an area of bone stronger than it was before. The phrase, “Use it or lose it”, applies to bones. The more you use them, the stronger they will be! Running has this effect on the bones in your legs. The impact of your body weight with each step places stress on the bones in your leg causing them to build up better and stronger constructs of bone in those areas.
Another interesting example of this principle can be found on the international space station.
NASA/Tracy Caldwell Dyson – http://spaceflight.nasa.gov/gallery/images/station/crew-24/html/iss024e014263.html direct link
Astronauts that are in space do not have the same weight of gravity always placing stress on the bones that we do here on earth. In fact, this is one of the challenges when thinking of long term space travel. Astronauts’ bones become thinner over time in space, they lose bone mass much more quickly without gravity than they would on earth. Scientists are working on solutions to combat the loss of that bone to be able to sustain longer term space travel.
So, how do we combat bone loss on earth? Placing weight on your bones through exercise is an underutilized solution! Before you start exercising remember that you know your own body really well, but if you have a concern about your health or already have osteoporosis it would be wise to check with your doctor prior to starting an exercise program.
So what is the perfect exercise program to prevent bone loss?
In most cases, just starting doing something to start building your bone health is better than nothing at all! This is as long as you don’t hurt yourself, so always remember to prioritize safety!
The main principle to follow is to think about placing stress on your muscles and the bones that they are attached to.
Running as well as strength training exercises like squats, places stress on the bones in your legs. With exercises like running, while it might be great for building the bones in your legs, it does not place any significant weight on your upper arms. So don’t ignore the bones in your arms and shoulders!
For arms and shoulders trying some exercises such as lifting dumbbells is a great way to start. It can definitely seem intimidating, but if you focus on learning one thing at a time it is more manageable.
With these principles in mind, I will leave you with one exercise that will place stress through the bones in your arms. Below is a diagram of the bones in your arm.
A great arm exercise that is described below, is called a shoulder press. It places weight mainly on your humerus, radius, ulna, and wrist bones:
In a seated position, hold your dumbbells in line over your shoulder with palms facing forwards. Push the weight up vertically in line over your shoulders, keeping your hands over your elbows. Movements should be slow and controlled. Breath out while pushing up. Lower weights in line with palms facing forward the whole time, exhaling when you lower the weights. Repeat this for ~10-12 repetitions.
How much weight should you use?
This is where prioritizing safety is the most important thing. Starting with a very light weight to start out with is perfectly fine. 1-3 lbs is fine. Then you can build over time with your comfort level. To optimize building and safety, aiming for an amount of weight that makes your shoulders feel pretty tired at 9-10 repetitions is perfect.
Here is a great free resource on youtube that shows this exercise: Fitness Blender Video
Disclaimer: No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.
Human arm bones diagram. https://upload.wikimedia.org/wikipedia/commons/4/49/Human_arm_bones_diagram.svg
Introduction – Anatomy and Physiology – OpenStax. https://openstax.org/books/anatomy-and-physiology/pages/1-introduction.
Slowing bone loss with weight-bearing exercise – Harvard Health. https://www.health.harvard.edu/staying-healthy/slowing-bone-loss-with-weight-bearing-exercise.
Upper Body Split Workout – Shoulders and Lats Mass Building Video. https://www.youtube.com/watch?v=MHjJF_MnWBI&feature=youtu.be&t=1140.