Strength Training and Bone Density: What Actually Works

Strength training helps bone most when the load is progressive, meaning the weight or resistance increases over time, and when it works the hips and spine. Reviews in postmenopausal women find modest but real differences: less bone loss at the spine and hip in people who exercise than in those who do not. It works best combined with impact and balance exercise, enough calcium, vitamin D and protein, and medical advice if you already have low bone density.

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This guide explains how bone responds to load, what the trials have actually measured, which types of exercise load bone and which do not, a simple starter programme, and the safety points that matter if you have osteoporosis.

At a glance

• Load is the signal. Bone responds to forces that are greater than everyday activity. Progressive resistance training and impact exercise provide that; swimming and cycling largely do not.
• Effects are modest and site-specific. Exercise mainly benefits the bones being loaded, and changes in density are measured in single-digit percentages.
• Aim for at least two strength sessions a week, as most national guidelines recommend, plus balance work if you are older.
• Nutrition supplies the raw materials: calcium, vitamin D and protein all matter.
• If you have osteoporosis or a past fracture, talk to your doctor or a physiotherapist before starting, and avoid loaded forward bending and twisting of the spine.

Bone is living tissue

Bone is constantly being broken down and rebuilt. The US National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) explains that in younger years new bone forms faster than old bone is removed, and that bone mass peaks for most people by the mid to late 20s. After that, the balance slowly tips the other way.

For women, loss speeds up around menopause. The NIH Office of Dietary Supplements notes that falling oestrogen during menopause and for about five years afterwards leads to faster bone breakdown than formation, and so to a rapid drop in bone mass. Men lose bone too, usually more gradually and later.

The rate of loss is not fixed. Physical activity, nutrition, smoking, alcohol, some medicines and some health conditions all affect it.

How muscle and bone work together

When muscles pull on bone and when the body absorbs impact, bone cells sense the strain and respond by strengthening the areas under stress. Without that stimulus, bone has less reason to maintain its density, which is one reason long periods of inactivity or bed rest lead to bone loss.

NIAMS describes weight-bearing exercise as activity that produces a force on bones that makes them work harder, and notes that resistance exercise also stresses bone in a way that can make it stronger. Stronger muscles also support joints and improve balance, which lowers the chance of a fall. For bone health, avoiding the fall matters as much as the density of the bone that lands.

What the evidence shows

The main review

The best-known summary is the Cochrane review of exercise for bone health in postmenopausal women (Howe and colleagues, 2011). Compared with not exercising, people who did combinations of exercise types had on average 3.2% less bone loss at the spine, and those who exercised had on average about 1% less bone loss at the hip. The authors described the effect as relatively small but possibly important, and noted that the reporting quality of the pooled studies was low.

The same review found that progressive resistance training for the legs was the most effective single approach for hip bone density, and that combination programmes were most effective for the spine. That is the site-specific effect: bone responds where it is loaded.

Higher-intensity training under supervision

For a long time, people with low bone density were steered towards light exercise only. The LIFTMOR trial in Australia, published in 2018, tested a different approach. It randomised 101 postmenopausal women with low bone mass to either a supervised, high-intensity programme of heavy lifts and jumping drills twice a week for eight months, or a low-intensity home programme. The supervised group improved bone density at the lower spine and hip and gained strength and function, and no serious injuries were reported.

Two points matter. The participants were screened, trained carefully and supervised throughout, and the programme built up gradually. It is evidence that well-run, progressive training can be appropriate for some people with low bone mass, not a reason to start lifting heavy weights alone.

What guidelines recommend

The World Health Organization recommends muscle-strengthening activity on at least two days a week for adults, and for people aged 65 and over, varied activity that includes balance and strength on at least three days a week. Australia’s physical activity guidelines, the UK Chief Medical Officers’ guidelines and the Physical Activity Guidelines for Americans give similar advice on strength work. Healthy Bones Australia’s exercise guidance combines progressive resistance training on two to three days a week with regular weight-bearing impact and balance exercise.

Which activities load bone

Activity	Bone loading	What it adds	Notes
Progressive resistance training (weights, machines, heavy bands)	High at the bones worked	Muscle strength, bone loading at hip and spine	Most-studied option for bone density; increase load over time
Impact exercise (jumping, skipping, hopping, stair drills)	Moderate to high	Quick, varied forces that bone responds to	Start low; not suitable for everyone with osteoporosis
Brisk walking, hiking, stair climbing	Low to moderate	Heart health, daily movement	Good habit, but on its own a gentle bone stimulus
Dancing, racquet sports, team sports	Moderate	Impact, changes of direction, balance	Enjoyable ways to add impact
Balance training, tai chi	Low	Lower risk of falls	Important with age even though bone loading is small
Swimming, water exercise, cycling	Very low	Fitness, joint-friendly movement	Valuable for health but little stimulus for bone
Yoga and Pilates	Low	Flexibility, core strength, balance	Some positions involve deep spinal bending; get advice if you have osteoporosis

If you are building a habit of moving more through the day, our guide to everyday movement covers the time outside formal exercise, and our guide to balance habits for healthy ageing covers fall risk.

A simple starter programme

You do not need a gym. Bodyweight, resistance bands or dumbbells are enough to begin. Our guide to choosing resistance bands covers equipment if you are starting at home.

1. Check with your doctor first if you have osteoporosis, a past fracture, a heart condition, joint problems or have been inactive for a long time.
2. Warm up for five minutes with marching, walking or gentle stepping.
3. Squats or sit-to-stands: 2 sets of 8 to 12, using a chair behind you for safety.
4. Lunges, step-ups or split squats: 2 sets of 8 to 10 each leg, holding support if needed.
5. Push-ups: 2 sets of 8 to 10, against a wall or bench to begin.
6. Rows with a band or dumbbell: 2 sets of 10, keeping your back straight and chest up.
7. Overhead or shoulder press: 2 sets of 8 to 10, if your shoulders allow.
8. Balance practice: stand on one leg for up to 30 seconds each side, near a bench or wall.
9. Repeat two to three times a week, with a rest day between sessions.
10. Progress gradually. When the last two repetitions feel easy with good form, add a little weight, resistance or another set.

If you are cleared for it, small amounts of impact, such as heel drops or low jumps, can be added on other days. Working with a physiotherapist or accredited exercise professional is the safest way to progress to heavier loads.

Nutrition’s supporting role

Exercise provides the signal; nutrition provides the materials.

Calcium

Calcium is the main mineral in bone. Recommended intakes vary by country and age, so check your local guidance.

Group	Australia and New Zealand	United States	United Kingdom
Women 19 to 50	1,000 mg a day	1,000 mg a day	700 mg a day
Women 51 and over	1,300 mg a day	1,200 mg a day	700 mg a day
Men 19 to 70	1,000 mg a day	1,000 mg a day	700 mg a day
Men over 70	1,300 mg a day	1,200 mg a day	700 mg a day

Food is the preferred source: dairy, calcium-fortified plant milks, tinned fish with soft bones, tofu set with calcium, and some leafy greens. If your doctor suggests a supplement, our guide to calcium citrate versus carbonate explains the label differences, and our supplements evidence and label guide covers how to judge any supplement.

Vitamin D

Vitamin D helps the body absorb calcium from food. Most people make much of their vitamin D from sunlight, so needs depend on where you live, the season, your skin and how much time you spend outdoors. Our guide to vitamin D, sunlight and testing explains how to think about it, and whether testing makes sense is a question for your doctor.

Protein

Bone is a mineral laid down on a protein framework. An expert consensus endorsed by ESCEO and the International Osteoporosis Foundation reported that protein intakes at or above 0.8 g per kilogram of body weight a day are associated with higher bone density and slower bone loss in older people, provided calcium intake is adequate, while noting that longer trials are still needed. Our guide to protein and muscle after forty covers how to reach that through food.

By life stage

20s to 30s: the tail end of building peak bone mass. Regular strength and impact exercise now sets a higher starting point for later life.

40s to 50s: for many women, bone loss speeds up around menopause. Starting or stepping up progressive resistance training at this stage is well supported.

60s and beyond: strength training remains effective and important. Good technique and qualified instruction matter more, and balance work becomes a priority because it lowers the risk of the falls that cause most fractures.

If you have osteoporosis or low bone density

Exercise is still recommended for most people with osteoporosis, but the type matters. Talk to your doctor and ideally a physiotherapist or accredited exercise physiologist first. Points they will commonly raise include:

• avoiding fast, loaded or repeated forward bending of the spine, such as sit-ups or toe-touches with weight;
• avoiding forceful twisting of the spine, especially under load;
• learning to bend at the hips and knees, not the back, when lifting;
• building load gradually and under supervision if you have had a spinal fracture;
• prioritising balance training and making your home safer to reduce falls.

Common mistakes

• Relying on walking alone. It is great for health but a gentle stimulus for bone.
• Keeping the weight the same for years. Bone responds to loads that progress; the Cochrane review found progressive resistance training most effective for the hip.
• Only training the arms or only the legs. The effect is site-specific, so include hips, spine and upper body.
• Swapping all strength work for swimming or cycling. Both are valuable, but neither loads bone much.
• Doing loaded sit-ups or twists with osteoporosis. These movements put the spine at risk.
• Ignoring balance. Most fractures in older adults follow a fall.
• Skipping calcium, vitamin D or protein. Training without the raw materials limits the benefit.
• Expecting fast results. Bone changes slowly and the measured differences are small; strength and confidence usually improve much sooner.

Sources this guide draws on: Cochrane review of exercise for bone health in postmenopausal women (Howe and colleagues, 2011); LIFTMOR randomised trial, Journal of Bone and Mineral Research (Watson and colleagues, 2018); National Institute of Arthritis and Musculoskeletal and Skin Diseases, bone health and exercise information; NIH Office of Dietary Supplements, calcium fact sheet; World Health Organization guidelines on physical activity and sedentary behaviour (2020); Australian physical activity and exercise guidelines; Healthy Bones Australia exercise guidance; NHMRC Nutrient Reference Values for Australia and New Zealand; ESCEO and International Osteoporosis Foundation consensus on dietary protein and bone health.

Frequently asked questions

Can strength training increase bone density?

It can slow loss and, in some trials, produce small increases at the bones being loaded. The Cochrane review found modest differences at the spine and hip, and the supervised LIFTMOR trial found improvements in women with low bone mass. Results take months and are measured in small percentages.

How often should I lift weights for bone health?

Most guidelines recommend muscle-strengthening activity on at least two days a week. Two to three sessions with rest days between, gradually increasing the load, is a common approach.

Is walking enough to protect my bones?

Walking is good for overall health and provides some bone loading, but on its own it is a gentle stimulus. Adding resistance training, some impact if appropriate, and balance work gives bone a stronger signal.

Is it safe to lift weights with osteoporosis?

For many people, yes, with the right guidance. Supervised, progressive training has been studied in women with low bone mass without serious injuries. Talk to your doctor and a physiotherapist first, and avoid loaded forward bending and twisting of the spine.

What is the best exercise for hip bone density?

In the Cochrane review, progressive resistance training for the legs was the most effective single type for the hip. Squats, lunges, step-ups and leg presses are common examples.

Is it too late to start strength training after 60?

No. Strength training is effective at any age, and the gains in muscle, balance and confidence can lower the risk of falls. Start with light loads and good technique, and get advice if you have health conditions.

Bone responds to how you live. Lift something a little challenging two or three times a week, keep moving every day, practise balance, eat for calcium, vitamin D and protein, and get personal advice if your bones are already fragile.

This article is educational only and is not medical advice. If you have osteoporosis, a past fracture or another health condition, talk to your doctor or pharmacist, or a physiotherapist, before starting a new exercise programme or supplement.