Exercise is good for bone health | Total Performance Physical Therapy

Exercise is good for bone health

December 3, 2012

Exercise is often encouraged to increase muscular strength, but what you may not know is that it can also increase the strength of your bones and decrease your risk for osteoporosis.

Bone is made up of three major components: cells, collagen fibers, and apatite.

  1. Cells:  There are two major types of cells found in bone.  They are known as the osteoblasts and the osteoclasts.  Osteoblast cells are the cells that are in charge of building more bone when stimulated by various signals from the body.  Osteoclast cells are the cells that breakdown bone in response to other signals from the body.
  2. Collagen fibers:  These fibers provide tensile strength to bones so when muscles that attach to certain bones pull on them they do not tear a piece of the bone off.  It also provides a foundation for bone matrix (or the framework of bone) which is filled in by a substance called apatite.
  3. Apatite: This is the substance that makes bone hard.  It is made up of a mixture of calcium, phosphate, and water which makes bone cement-like.

The majority of bone growth typically happens between the ages of 11-14 for girls and between 13-17 for boys.  During this time, osteoblast cell activity is greater than osteoclast cell activity.  This means that there is more bone formation than loss and therefore bones are able to grow.  Bone growth as it happens at this stage in life does not happen to this extent throughout life.  People typically reach what is called their peak bone mass at around the age of 22.  At this point you have reached the greatest amount of bone that you will have in your life.  Women typically reach their peak bone mass first due to earlier onset of puberty.

After you have reached your peak bone mass, osteoblast cell activity is equal to that of osteoclast cell activity which means that you aren’t really losing bone, but you aren’t gaining it.  As you start to age, the opposite of bone growth happens.  Osteoclast cell activity is actually greater than osteoblast activity so you are losing bone because bone breakdown dominates over bone formation.  Some research has shown that this may correlate with decreasing amounts of estrogen as you age.  It has been shown that estrogen plays a role in preventing bone breakdown.

So what can you do to achieve the best peak bone mass and maintain it once you have achieved it?

As you have probably heard, calcium is crucial for bone health.  If you do not get enough calcium, osteoclasts are signaled to start the breakdown of bone to make sure that your body has the right amount of calcium to maintain regular function.  What some may not know is that vitamin D is also important as there is a form of it that helps with the absorption of calcium from the intestine.  So if you are not getting enough vitamin D, the calcium you do consume through food or supplements may not get into your body (it will just go through your GI tract and be excreted as waste) because if you are vitamin D deficient it may not get absorbed.

For more information on physical therapy services head to www.totalperformancept.com.

Another thing you can do is exercise!  It has been shown that exercise, especially with weights, can increase osteoblast activity and therefore bone formation.  There is a law that explains this called Wolf’s Law.  It states that bone will buildup where stress is put on bones.  So putting stress on bones when doing things such as jumping, hopping, running, lifting weights, or any kind of resistance training will encourage the formation or growth of bone during that period of growth in your teens.  This will allow you to achieve a greater peak bone mass.  If you have already reached your peak bone mass, exercise is still equally as important.  It allows you to maintain more of that peak bone mass that you attained so that as you age your bones still maintain a certain density.  This puts you at less of a risk for development of osteoporosis.  Exercise also helps increase muscle strength and allows you to develop better balance that will prevent falls and, therefore, decreases your risk for fractures.

You shouldn’t just choose to start any exercise program.  Some exercise programs are not appropriate for all age groups or skill levels.  A 10 year old and a 60 year old should not be performing the same exercises.  For a long time people believed that children should not perform resistance or strength training.  According to the American Academy of Pediatrics, resistance training does not have an adverse effect on growth in children.  Despite this it is still important to make sure that when children strength train, they use proper technique, progress with exercises appropriately, and do not perform maximal weight lifts as this is not appropriate.  On the other end of the spectrum, the older adult doesn’t necessarily need to take it easy when it comes to resistance exercise.  Research has shown that high intensity resistance training can cause large increases in strength in the older adult.  A more gradual progression of exercises may be prescribed if they have other conditions such as arthritis, obesity, neurologic disease, cardiovascular impairment, and previous joint injuries.

So why not go to a personal trainer for a strengthening exercise program?  Although personal trainers know a variety of ways to strengthen different muscles, they do not have knowledge about different medical conditions and how they may affect your ability to exercise.  They often prescribe exercise programs that are too difficult for people, which can result in injury.   The physical therapist takes all details about a patient into consideration and can develop an exercise prescription that is appropriate for you.  They have an understanding of conditions such as diabetes, heart disease, cancer and many others that allow them to make decisions about what is best for you to do in terms of how often, how much weight, and what type of exercise you should do as well as how to make it harder when you are ready without causing injury.  They are also able to identify when you are not performing a particular exercise correctly  and can make sure that you are using the appropriate muscles for a particular exercise.  This will either help you reach a better peak bone mass or maintain more of your peak bone mass while decreasing your risk of injury.

For more information on physical therapy services head to www.totalperformancept.com.