What's the Best Exercise for Bone Density After 40?

When most people think about keeping their bones strong as they get older, they usually think about calcium and vitamin D.

Those nutrients are important, but there's another factor that doesn't always get enough attention.

Exercise.

Your bones are living tissue. They constantly respond to the mechanical forces placed on them, and that response becomes increasingly important as we age.

But what type of exercise actually works best?

Is lifting weights enough? Should you be running? Does walking provide any meaningful benefit? And how much exercise do you really need to protect your bones?

A new 2026 study published in The BMJ attempted to answer those questions by analyzing 124 randomized controlled trials involving 18,429 adults aged 40 and older.

The researchers compared different exercise modalities, examined their effects on bone mineral density, and even attempted to identify how much exercise was needed to produce clinically meaningful improvements.

The results were interesting, particularly for people who assume that maintaining bone density requires heavy resistance training.

Why Bone Density Becomes More Important After 40

Bone mineral density, or BMD, measures the amount of mineral contained in a given area of bone.

It's commonly assessed using a dual-energy X-ray absorptiometry scan, better known as a DXA scan.

Although bone density isn't the only factor determining bone strength, lower BMD is strongly associated with increased fracture risk.

As we get older, the balance between bone formation and bone breakdown gradually changes.

Bone remodeling continues throughout life, but the rate at which new bone is formed may no longer keep pace with the amount being resorbed.

For women, this process can accelerate considerably around menopause because of declining estrogen concentrations.

Men also experience age-related bone loss, although the pattern is generally more gradual.

The consequences can be significant.

Fractures involving the hip, spine, and other skeletal sites can lead to substantial reductions in mobility, independence, and quality of life.

And once someone has experienced a fragility fracture, their risk of experiencing another fracture increases.

That's why preserving bone strength before significant bone loss occurs is so important.

The good news is that bone responds to mechanical loading.

When muscles contract and weight-bearing forces travel through the skeleton, they create mechanical signals that can influence bone remodeling.

But not all exercise produces the same loading patterns.

And that's what makes this study particularly useful.

How the Researchers Conducted the Study

The researchers performed a hierarchical Bayesian network meta-analysis of randomized controlled trials.

That's a complicated name for an approach that allows researchers to compare several interventions using both direct and indirect evidence.

Instead of examining only resistance training versus no exercise, for example, the researchers could evaluate how resistance training compared with walking, aerobic exercise, mind-body exercise, and other modalities across a connected network of trials.

They included studies involving adults aged 40 or older who participated in structured exercise programs.

The exercise interventions were divided into six categories.

The researchers examined changes in bone mineral density at three locations: the lumbar spine, femoral neck, and total hip.

They also analyzed incident fractures where trials reported that outcome.

The interventions lasted between 12 and 208 weeks, and most trials enrolled women.

One thing I appreciate about this study is that the researchers didn't stop at asking whether exercise worked.

They also attempted to determine how much exercise was needed to produce a meaningful change in bone density.

That makes the findings more practical, although the dose estimates come with some important limitations.

The Main Finding: Brisk Walking or Jogging Performed Surprisingly Well

Of all the exercise categories evaluated, brisk walking or jogging produced some of the strongest estimated improvements in bone mineral density.

Compared with control groups, it was associated with increases at all three skeletal sites.

At the lumbar spine, brisk walking or jogging increased BMD by an estimated 0.013 g/cm² compared with control.

At the femoral neck, the estimated difference was 0.009 g/cm².

And at the total hip, the difference was 0.021 g/cm².

That last result was particularly interesting because brisk walking or jogging was the only exercise category with a statistically credible improvement in total hip BMD in the primary analysis.

However, I wouldn't rush to conclude that walking is superior to every other form of exercise.

The total hip estimate came from only three trials involving 68 participants in the brisk walking or jogging category.

That's a relatively small evidence base, and the certainty was rated low.

The participants in those trials were also all women, with an average age of approximately 45.

So the findings don't establish that brisk walking will produce the same hip bone density improvements in an 80-year-old man with established osteoporosis.

The results are encouraging, but the strength of the evidence matters just as much as the size of the estimated effect.

Does This Mean Walking Is Better Than Weightlifting?

Not necessarily.

And this is where I think the study could easily be misinterpreted.

The researchers found that resistance training improved lumbar spine BMD by approximately 0.005 g/cm² and femoral neck BMD by a similar amount compared with control groups.

Those are statistically credible improvements.

But the magnitude of the benefit was smaller than the estimates for brisk walking or jogging.

Does that mean someone concerned about osteoporosis should stop lifting weights and start walking instead?

I certainly wouldn't recommend that.

Bone density is only one component of fracture prevention.

Muscle strength, balance, coordination, and the ability to recover from a loss of balance also influence whether someone falls and whether that fall results in an injury.

Resistance training directly addresses several of those factors.

It also produces mechanical loading through muscular contractions, which can help stimulate bone adaptation.

Another consideration is that resistance training programs vary enormously.

A supervised program using progressively heavier loads is very different from a program involving light resistance bands without meaningful progression.

The researchers grouped these interventions into broad exercise categories, which makes it difficult to determine whether specific resistance training approaches might outperform others.

I also think it's worth remembering that the study compared average results across different populations and interventions.

It wasn't one giant randomized trial assigning identical participants to six perfectly standardized exercise programs.

My preference would be to combine resistance training with regular weight-bearing aerobic activity rather than choosing one over the other.

That approach supports bone health while also addressing strength, mobility, and cardiovascular fitness.

How Much Exercise Do You Actually Need?

This might be the most useful part of the study.

The researchers examined the relationship between exercise dose and changes in bone mineral density.

They expressed exercise dose in MET-minutes per week.

A MET, or metabolic equivalent of task, represents the energy cost of an activity relative to resting energy expenditure.

For example, an activity performed at 4 METs requires approximately four times the energy expenditure of resting.

You calculate weekly MET-minutes by multiplying the activity's MET value by the number of minutes performed.

The researchers found that clinically meaningful improvements in bone density generally began appearing around 400 to 600 MET-minutes per week, depending on the skeletal site.

They estimated the following thresholds across exercise modalities:

These thresholds were model-based estimates, not precise individual prescriptions.

The researchers also found that improvements generally approached a plateau around 900 to 1,000 MET-minutes per week.

For context, here's what 600 MET-minutes could look like using approximate activity intensities.

The practical message is encouraging.

You may not need an extreme exercise program to support bone density.

But I wouldn't interpret 600 MET-minutes as a magic number.

The dose-response curves were generated from statistical models, and the researchers acknowledged uncertainty in the estimates, particularly at higher exercise volumes.

They also used a study-defined threshold for what constituted a clinically important BMD change.

That threshold is useful for research, but it doesn't guarantee a particular reduction in fracture risk for an individual.

More Exercise Isn't Necessarily Better for Bone Density

Another interesting finding was that the relationship between exercise dose and bone density wasn't linear.

For most exercise categories, the researchers observed an inverted U-shaped relationship.

In other words, benefits increased as exercise dose increased, then appeared to level off or decline at higher volumes.

This doesn't mean exercising more than three hours per week is bad for your bones.

There are several possible explanations.

People assigned to more demanding exercise programs may have had difficulty maintaining the prescribed intensity or frequency.

The higher-dose groups may also have differed in age, baseline bone density, training history, or other characteristics.

And fewer studies examined very high exercise doses, making those estimates less reliable.

The researchers themselves acknowledged that the apparent decline at higher volumes could reflect statistical uncertainty rather than a true physiological effect.

I wouldn't use this study to discourage someone from training more if they enjoy it and are recovering appropriately.

The more useful takeaway is that bone health benefits don't necessarily require enormous amounts of exercise.

Can Exercise Actually Prevent Fractures?

Improving bone density is important, but preventing fractures is ultimately the outcome we care about most.

The researchers analyzed fracture incidence separately using 26 randomized trials involving 11,132 participants.

Two exercise categories showed statistically credible associations with lower fracture odds.

Mixed aerobic exercise was associated with approximately 71% lower fracture odds, while mind-body exercise was associated with approximately 42% lower odds.

Those sound like dramatic effects.

But I would be very cautious about treating them as reliable estimates of how much exercise prevents fractures.

The mixed aerobic exercise estimate came from just two trials involving 119 participants in that exercise category.

The mind-body exercise estimate was also supported by only two trials.

The certainty of the fracture evidence was rated low.

And importantly, the absence of a statistically credible fracture reduction for resistance training or brisk walking doesn't establish that those activities are ineffective.

It means this particular analysis couldn't demonstrate a clear reduction.

The mind-body findings are still interesting because activities such as tai chi may improve balance and postural control.

That could potentially reduce falls, even if changes in bone density are relatively modest.

It's a useful reminder that fracture prevention isn't exclusively about increasing bone mineral density.

Does Age Change How Your Bones Respond to Exercise?

The researchers also investigated whether age, sex, and body mass index influenced the results.

They found that adults aged 40 to 60 generally appeared more responsive to exercise than those older than 60.

Men also appeared more likely to reach the study's predefined bone density improvement thresholds than women.

Participants with a BMI in the normal range tended to show more favorable responses than those with overweight or obesity.

However, the certainty of these subgroup findings was very low.

That means I wouldn't interpret them as evidence that exercise is substantially less worthwhile for older adults or women.

There are several reasons why bone density responses might differ between populations, including hormonal status, baseline bone health, exercise tolerance, and the intensity of training participants can safely perform.

The study also included substantially more women than men, which limits confidence in some sex-specific comparisons.

What I take from these results is that starting earlier may be beneficial.

If you're in your 40s or 50s, that's a good time to establish consistent weight-bearing exercise and resistance training habits.

But if you're 70 or 80, there's still plenty of reason to exercise.

Maintaining strength, mobility, balance, and independence can be extremely valuable even when measurable changes in BMD are small.

What About Calcium, Vitamin D, and Protein?

Although this study focused on exercise, I think it's worth discussing nutrition.

Bone remodeling requires adequate nutritional support.

Calcium is a major structural component of bone, and vitamin D helps regulate calcium absorption and metabolism.

Protein also matters because bone contains a substantial organic matrix, primarily collagen, and adequate protein supports the muscles responsible for loading and protecting the skeleton.

But the relationship between these nutrients and bone health isn't as simple as taking larger doses.

If someone already consumes adequate calcium, additional supplementation may not provide meaningful benefits.

The same principle applies to vitamin D. Correcting a deficiency is important, but taking large amounts when levels are already sufficient doesn't necessarily improve bone density or prevent fractures.

And while collagen is an important structural component of bone, that doesn't mean taking collagen supplements automatically increases bone mineral density.

This particular meta-analysis did not test whether calcium, vitamin D, protein, or collagen supplementation enhanced the effects of exercise.

Some included trials provided calcium or vitamin D as part of their protocols, but the analysis wasn't designed to establish the independent benefits of those nutrients.

At Simply Good Supplements, we offer products such as Essentials and Collagen that can fit into a broader nutrition routine.

However, I wouldn't claim that either product increases bone density based on this study.

The more important starting point is ensuring that your overall diet provides enough calcium, vitamin D, protein, and energy to support healthy bone metabolism.

For people with osteoporosis or elevated fracture risk, nutritional assessment and medical treatment may also be necessary.

How I Would Structure an Exercise Program for Bone Health

If I were designing a general bone-health exercise routine for an otherwise healthy adult over 40, I'd focus on three things.

First, regular weight-bearing activity. Brisk walking is accessible, inexpensive, and easy to incorporate into most schedules. Jogging may provide additional impact loading for people who can tolerate it, but it isn't appropriate for everyone.

Second, progressive resistance training. I'd include exercises targeting the major muscle groups, particularly the hips, legs, back, and trunk. The goal would be to gradually improve strength while maintaining proper technique.

Third, balance and coordination. Especially as people get older, I'd incorporate exercises that challenge stability in a safe, controlled environment.

A reasonable weekly starting structure might look like this:

This is an illustrative routine, not a protocol directly tested in the meta-analysis.

It also isn't intended as a prescription for someone with severe osteoporosis, recent fractures, or significant balance problems.

For those individuals, exercise selection and progression should be discussed with a qualified healthcare professional or physical therapist.

Certain high-impact activities and loaded spinal movements may need modification depending on fracture history and skeletal health.

The goal is to provide enough mechanical stimulus to support bone health without creating unnecessary injury risk.

The Study Limitations That Matter Most

Although this was a large meta-analysis, there are several limitations worth understanding.

First, the included trials were highly variable.

They used different exercise protocols, participant populations, intervention lengths, and training intensities.

That makes comparisons between broad exercise categories difficult.

Second, only 28 of the 124 trials were rated as having a low overall risk of bias.

The researchers identified some concerns in 59 trials and high risk of bias in another 37.

Third, the evidence supporting some of the highest-ranked interventions was relatively limited.

As mentioned earlier, the total hip findings for brisk walking or jogging were based on only 68 participants.

Fourth, the dose-response analysis relied on estimated energy expenditure.

MET-minutes are useful for comparing activities, but they don't fully capture the mechanical loading characteristics that influence bone adaptation.

For example, two activities could require similar energy expenditure while producing very different forces through the skeleton.

Fifth, the researchers defined clinically meaningful improvements as approximately 1% to 2% of baseline BMD.

That's a reasonable research benchmark, but it doesn't mean every participant achieving that change would experience a measurable reduction in fracture risk.

Finally, fracture outcomes were supported by fewer trials than bone density outcomes.

The fracture findings are interesting, but they need stronger confirmation.

What I Think This Study Actually Tells Us

I think this is a useful study because it challenges the assumption that bone health requires a complicated or particularly intense training program.

Brisk walking or jogging performed well across multiple skeletal sites.

Combined aerobic and resistance training also produced favorable results.

And resistance training itself remained beneficial, even when it wasn't the highest-ranked intervention.

But I wouldn't interpret the rankings too literally.

The best exercise for bone health isn't necessarily the activity with the largest estimated BMD change in a network meta-analysis.

It's the activity, or combination of activities, that provides an appropriate mechanical stimulus while also improving strength, balance, and overall physical function.

And it has to be something a person can perform safely and consistently.

A well-designed resistance training program combined with regular walking may be considerably more practical than chasing a specific exercise modality because it ranked first in one analysis.

I also think the dose-response findings are encouraging.

You don't necessarily need to spend hours in the gym every day to support skeletal health.

But consistency matters, and bone adaptations generally occur over months rather than days or weeks.

The Bottom Line

A new 2026 meta-analysis published in The BMJ examined 124 randomized controlled trials involving 18,429 adults aged 40 and older.

The researchers found that structured exercise can help preserve or improve bone mineral density, with brisk walking or jogging and combined aerobic-resistance training showing particularly favorable results.

They also estimated that clinically meaningful improvements may begin around 400 to 600 MET-minutes per week, depending on the skeletal site.

Mixed aerobic and mind-body exercise were associated with lower fracture odds, although those findings were supported by low-certainty evidence.

My takeaway is that protecting your bones doesn't require an extreme exercise program. Regular weight-bearing activity, progressive resistance training, and balance work provide a practical foundation for long-term bone health.

If you're over 40 and haven't been exercising consistently, this is another good reason to start.

And if you're already training regularly, it's worth making sure your routine includes more than just one type of exercise.

Your bones, muscles, and overall physical function will benefit from a well-rounded approach.

References

Lu C, Li L, Zhang L, et al. Effect of exercise on bone health in middle aged and older adults: hierarchical network meta-analysis of randomised trials. BMJ. 2026;394:e100561. https://doi.org/10.1136/bmj-2026-100561.