Diseases and Conditions

What do you mean by weight-bearing exercise?

March 22, 2017

Rheumatology primarily, and thankfully, deals with rare conditions with a few notable exceptions.  Osteoporosis being one of those.  According to the CDC

Percent of men 50 years of age and over with osteoporosis of the femur neck or lumbar spine: 4%

Percent of women 50 years of age and over with osteoporosis of the femur neck or lumbar spine: 16%

That’s a lot of people.  It’s also important note, that post-menopausal women are not the only ones that develop osteoporosis.  Men do.  People with inflammatory diseases do.  People that have GI absorption problems also do as well as people that don’t move a whole lot.

What is osteoporosis?

Osteoporosis is a condition that is characterized by weakening of bone.  People that have osteoporosis don’t feel they have osteoporosis.  It’s painless and there are no symptoms, until that is, something very bad happens like a fracture.  Bone strength is determined by bone mass and bone quality.  Think of a tree branch.  Branch A just fell off a healthy tree.  There was a bad storm and it just fell.  Structurally it’s normal.  Now you try to break it in half.  It’s a bit difficult to do.  Now you have Branch B.  This branch fell off a termite infested tree.  It’s partially hollowed out, i.e., the “wood” mass is significantly lower.  You try to break Branch B in half…easy peasy.  Osteoporosis = bone like Branch B.  Minor trauma in osteoporotic bone can result in a fracture.

Risk factors for osteoporosis

The next question is what are some of the risk factors that predispose someone to develop osteoporosis.  The good news is that some of these risk factors can be modified.  The bad news is that some risk factors cannot.

Things you CAN’T change

  • Advanced age
  • Ethnicity (white and Asian)
  • Early menopause
  • Slender build (< 127lbs)
  • Maternal history of hip fragility fracture
  • Certain medical conditions

Things you CAN change

  • Low calcium intake
  • Low vitamin D intake
  • Estrogen deficiency
  • Sedentary lifestyle
  • Cigarette smoking
  • Alcohol excess ( > 2 drinks/day)
  • Caffeine excess (> 2 servings/day)
  • Certain medications

Medical conditions

  • Rheumatoid arthritis
  • Ankylosing spondylitis
  • Lupus
  • Hyperthyroidism
  • Hyperparathyroidism
  • Alcoholism
  • Eating disorders
  • Inflammatory bowel disease
  • History of gastric bypass
  • Celiac disease
  • Renal failure
  • Multiple myeloma

There are a lot more conditions, but this is a quick list of the common ones.

Medications

  • Steroids!!! Like prednisone, methylprednisolone, dexamethasone, etc.
  • Excess thyroid meds
  • SSRIs
  • Proton pump inhibitors, used for heartburn

Before making any changes with your meds, please talk with your doctor. 

How to measure bone density?

Bone density is measured using dual energy x-ray absorptiometry (DEXA).  Just say DEXA, the first word is way too long and complicated.  Sometimes bone density can be measured with a special type of CT or ultrasound but this is not typical and usually is reserved for unusual situations.

The body parts that are typically measured are the lumbar spine, the hip, the femoral neck, and the forearm.  Sometimes the heel is also included.  These areas are best at predicting future fractures, which when you think about it, is what we’re trying to do: Prevent future fractures.

Typically, DEXAs are repeated every two years.  Again, there are some exceptions where DEXAs may be obtained more frequently.  For example, if I have a patient on a “boat-load” of steroids for systemic vasculitis for months and months on end, I may want to repeat the DEXA annually.

Why is it important to treat osteoporosis?

The answer to this question is very simple.  Prevention of fractures.  Other than the fact that fractures are incredibly uncomfortable, multiple studies have shown that fragility fractures particularly hip fractures, increase the risk of dying…  Yes you heard me, dying.  A recent article found that the one year risk of death was 23.6% after sustaining a hip fracture.  This finding is in line with most of the literature.  I don’t know about you but I don’t like these odds.

How to increase bone density?

The answer to this question is not simple.  The simple answer is eat a healthy diet, spend some time in the sun, if you smoke stop, supplement with calcium and vitamin D, regularly perform weight-bearing exercise, and medications.  The problem I have with this advice is that for the most part it is extraordinarily vague, except for the medication bit which will be covered in future posts.

What is weight-bearing exercise?

I’d like to focus on weight-bearing exercise, more specifically, what constitutes weight-bearing exercise.  I get this question a lot.

Before answering, “what is weight-bearing exercise”, we need to know what is NOT weight-bearing exercise.

Swimming is NOT weight-bearing exercise.

Cycling is NOT weight-bearing exercise.

Rowing is NOT weight-bearing exercise.

Don’t get me wrong, these exercises are excellent exercises for cardiovascular health, but they won’t help improve bone mass.  Weight-bearing exercises refers to exercises where you need to move your body against gravity.  These exercises can then be classified into high-impact and low-impact.  High-impact activities are better at building bone density but everyone has their own limits.  If you have severe osteoarthritis you may not be physically capable of performing high-impact activities.  Safety is a concern.  The National Osteoporosis Foundation has a nice list of activities.

High impact weight-bearing exercises are important but they are not the only factor in the equation.  Another major factor are falls, more specifically the prevention of falls.  Hip fractures almost always are directly caused by falls.  Having osteoporosis simply increases the risk of a fall that results in a fracture as opposed to a nasty bruise.  Some of the greatest fall risks include the following:

  • Frailty
  • Visual impairment
  • Cognitive impairment
  • Problems with your legs, this includes osteoarthritis of the knees
  • A cluttered home environment
  • A previous fall within the past 6 months.  This is actually number one on the list.

To help prevent falls, it’s important to try to correct some of the above.  It’s also important to perform activities that will help build muscle strength, balance, and mobility.  Most senior citizen exercise classes like the ones offered by the Silver Sneakers Program, focus on these types of exercises.

How much activity is necessary?

Again, this is difficult to quantify.

A recent Japanese study measured the number of steps per day continuously for 5 years and measured the bone density of participants’ heel on an annual basis.  They also measured the intensity of the activity.  After controlling for baseline density, age, and body mass, they found that bone health was optimal in elderly people who take at least 7000 to 8000 steps per day and/or spend at least 15-20 minutes per day at moderate activity.

It’s important to note that these people did not necessarily go to the gym.  Steps per day can be achieved in numerous natural different ways.  Blue Zone founder Dan Buettner has it as number #1 on the Power 9® list, MOVE NATURALLY.  If you’ve read some of my previous posts or actually heard me in clinic, you’ll know that I’m a huge fan of the Blue Zone Project.  We don’t need fancy supplements or gym memberships to achieve optimal health.  The following are a few examples on how to move naturally.

  • Walk, walk, walk.  Avoid using your car.
  • If you need to use your car, park further away.
  • Using stairs as much a possible, don’t use the escalator.
  • Start gardening.
  • Get rid of mechanical conveniences in the house.  I love my snow blower, but it has to go.

I hope that this has helped you.  If you retain only one thing, MOVE NATURALLY.  This is the secret to optimal bone health.

 

Disclaimer: the abovementioned information does not constitute medical advice.  Every case is unique.  Please contact your local rheumatologist or your physician for more information. 

References

CDC Osteoporosis Statistics

Rheumatology Secrets, 3rd edition

Guerra MT, et al. One-year mortality of elderly patients with hip fracture surgically treated at a hospital in Southern Brazil. Rev Bras Ortop. 2016 Dec 7;52(1):17-23.

National Osteoporosis Foundation

Shephard RJ, et al. Objective longitudinal measures of physical activity and bone health in older Japanese: the Nakanojo Study. J Am Geriatr Soc. 2016 Dec 9. doi: 10.1111/jgs.14553. [Epub ahead of print]

 

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