How to Exercise for Better Bone Health

Exercise early, often, and strategically

You’ve probably heard that exercise is important for bone health, but, if you’re like me, you want specifics. Which types of exercise are best for bones? Is walking as good as jogging? Do I have to lift heavy weights? How often should I exercise? How much benefit can I expect? At what stages of life does exercise matter most?

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After spending many hours reading the scientific literature and connecting with expert to inform my own practices, it feels like a good time to pause and take as step back. This post is my attempt to share the top things we need to know to reap the full benefits of exercise for bone health.

A good place to start is with a common misconception about bones. Bones are so much more than just rigid structures that hold us together. They are active, dynamic tissues, that are constantly being remodelled in response to internal and external signals. This is why physical activity can directly impact bone quality and quantity.

Here’s a snapshot of how our bone mass changes across the lifespan. It rises steadily during childhood, rockets during our teens, peaks in our 20s to 30s, then declines. In men, the decline is slow and gradual, while in women, there is a relatively steep decline after menopause, then a slower, steady decline.

Bone mass across the human lifecycle (Source: AmericanBoneHealth.org)

This timeline sets the stage for one of the most key aspects of bone health and exercise - timing.

1. Exercise early

The higher your peak bone mass, the better positioned you are to tolerate the inevitable declines we all face. Childhood and adolescence are crucial windows to invest in bone-building exercise - not to mention establishing healthy habits.

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According to a study by the National Osteoporosis Foundation: “Grade A evidence is available for positive effects of … physical activity, especially during the late childhood and peripubertal years.” Indeed, nearly 50% of peak adult bone mass is gained during adolescence, and, in women, 80–90% of peak adult bone mass is accrued by age 16 (see: review on exercise and bone health across the lifespan).

Importantly, these improvements can persist for years. For example, a randomized controlled trial of 89 healthy elementary school kids found a 4% increase in hip BMC (bone mineral content) after 7 months of jumping three times per week (100 box jumps). Eight years later, differences in bone mass were were still apparent, though tempered.

For me, this means I’ll be doing everything in my power to ensure that my three kids (twin girls, age 7, and a boy, age 12) are active as teens. Knowing the value of this investment helps fuel me to continue shuttling my kids to and from various sports, and weaving physical activity into our family weekends. It sometimes feels like an uphill battle, but I know it’s time well spent.

Exercise is also vital in later adulthood. At this point, it can help mitigate bone loss and reduce the risk of falling, not to mention a slew of other anti-aging benefits.

2. Exercise often

The impact of exercise on bones is modest, but can add up over time. Most studies of bone health look at several times per week, over six months or longer. For example, a 2015 review study on exercise and bone mass in kids reported that “Exercise interventions during childhood led to 0.6% to 1.7% greater annual increase in bone accrual”. Building 1% more bone may not sound like much, but if you do this over 10-15 years, you’re in a considerably better place.

The need for consistency comes through loud and clear in recent UK consensus guidelines for people with osteoporosis. They recommend that everyone with or without osteoporosis incorporates daily movement, spread out to avoid sitting. In addition, for those who can tolerate it, they recommend moderate impact physical activity on *most days* and muscle-strengthening activity two or three days per week.

3. Exercise strategically

If taking care of your bones is a top priority, it pays to exercise strategically. As much as I love swimming, yoga, and biking, I know that these exercises are not the best bang for my buck when it comes to bone health.

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There is a strong consensus that the two best types of activity for bone health are weight-bearing exercises, ideally with high impact (e.g. jumping, skipping, etc) and resistance training (e.g. lifting weights). Better yet - do both! This true across the lifespan, because the fundamental mechanisms are the same - exercise signals to the bones that they need to become stronger. Importantly, as we become older, we need to consider not only bone health but also the risk of falling, so activities that promote balance also become important.

The value of one of my favourite activities, walking, is a bit murky. It’s a weight bearing, which is great, but it’s not as beneficial as higher impact exercises like jogging and jumping. According to a 2012 review of bone mass and exercise in older adults: “Walking provides a modest increase in the loads on the skeleton above gravity and, therefore, this type of exercise has proved to be less effective in osteoporosis prevention.” In other words, resistance and high impact work get gold medals and walking gets a silver.

Now that we know what to do for our bones, let’s talk about expectations. How much can exercise move the needle for bone health?

How much can exercise help my bones?

The benefits of exercise on bone quality are modest but potentially meaningful. A 2011 Cochrane review on exercise and osteoporosis in postmenopausal women concluded: “Our results suggest a relatively small statistically significant, but possibly important, effect of exercise on bone density”.

Clearly, there are limits to what exercise can do, and it’s important to have realistic expectations. In older adulthood, you can’t expect to rebuild a bunch of new bone with exercise alone, but you can stave off some of the typical declines. In other words, don’t put all your eggs in the exercise basket.

For example, in the 2018 LIFTMOR study, 101 postmenopausal women (average age 65), were randomly assigned to follow a bone-building workout program with high intensity and resistance workouts (30 min, 5x per week, supervised), or a low intensity workout program (unsupervised). After 8 months, the BMD (bone mineral density) went up by an average of 3% in the bone-building group, but dropped by an average of 1% in the control group. For the hip, it went up by a 0.3% on average on the vigorous exercise program - which sounds discouraging until you see that the control group went down by 2% on average.

Changes in bone mineral densit in spine and hip after CON (low impact) or HiRIT (high intensity/resistance) for 8 months. BMD = bone mineral density; LS = Lumbar spine; FN = Femoral neck. Source: LIFTMOR trial.

The benefits of exercise depend not only on your exercise program, but also on who you are and how your body responds - two people can get very different results from the same exercise program. For example, in the study mentioned above, while the average gain in lumbar spine BMD (bone mineral density) was 3% in the bone building exercise group, it varied from zero to double this - nearly 6%. Similarly, the average loss in BMD in the control group was 1%, but it varied from a loss of 4% to a gain of nearly 2%. This wide range of responses is likely due to a combination of how each person implemented the program, how their body responded to it, and other factors that the study didn’t control, like diet.

Closing thoughts

To reap the greatest bone health rewards, exercise early, often, and strategically. Ideally, incorporate both resistance workouts and high-impact training into your routine several times per week. At the same time, bear in mind that the impact of exercise on bone health is modest, and shouldn’t be your only tool.

I also encourage you to balance what’s best for your bones with whatever truly moves you and keeps you coming back for more. Physical activity has so much to offer beyond bone health, both mentally and physically, that any type of regular movement is a win.

Personally, I plan to keep walking whenever I get the chance because it feels so good, especially when I’m strolling with a friend in a beautiful place. But, I also recognize that my bones need a little more help, so I’m committed to doing resistance work 2-3 times per week, and jogging a few times a week as well.

As always, this post only scratches the surface of this complex topic, and is not intended as a substitute for medical advice. To learn more, check out the resources below and talk to your healthcare team about your specific situation.

Thanks for joining me on this journey. I’m signing off to move my body!

Chana Davis @FueledbyScience

Resources

• Exercise tips for bone health (US National Institutes of Health)

• Exercise and diet for osteoporosis prevention (UK National Health Services)

• Exercise for people with osteoporosis (Osteoporosis Canada)

• Why Bone Health Should be a Priority (by

  Chana Davis @FueledbyScience
  )
  

Related podcast episodes

Bone Health Part 2: Osteoporosis Treatment with Dr. Joy Wu. Tune into Get Real Health with Dr. Chana Davis, Ep.55 on my website, Apple Podcast, or Spotify.

Bone Health Part 1: Osteoporosis Prevention with Dr. Joy Wu. Tune into Get Real Health with Dr. Chana Davis, Ep.54 on my website, Apple Podcast, or Spotify