Built to Load: An Exercise Physiologist's Guide to Bone Density and Osteoporosis

Your skeleton is a living tissue that rebuilds itself around the loads you put through it, and it quietly downgrades when you stop asking it to work.

Most people only think about bone density after a scan, a fracture, or a GP conversation that starts with the word "osteopenia". By then you're playing catch up. The better move is to treat bone like any other performance quality: something you train on purpose, measure, and progress. That's exactly how we approach bone health at In Between Performance, our exercise physiology clinic in Darlinghurst, Sydney.

How exercise increases bone density

Bone responds to strain. When you jump, lift or land, the bone bends ever so slightly. Cells buried inside it, called osteocytes, sense that deformation and signal the cells that build new bone to get to work. Physiologists call it mechanotransduction.

Think of it like sand at the beach. Get down there at sunrise, before anyone's walked on it, and the sand is light and fluffy. Your feet sink straight through. By mid morning, after hundreds of people have walked, run and played across it, that same sand is dense and firm underfoot. Nothing was added. It was the force pressing down on it, again and again, that packed it tight.

Bone works the same way. Put force through it, consistently, and it gets denser and stronger. The pressure isn't the threat to your skeleton. It's the thing that builds it.

Three things make a load worth adapting to:

Magnitude. Heavy beats light. A walk barely registers, a heavy deadlift does.

Rate. Fast, sharp forces like jumping and landing send a stronger signal than slow, steady ones.

Novelty. Bone gets bored. Varied directions and new challenges outperform the same repetitive pattern.

Bone also tunes out quickly. A handful of quality reps or jumps does most of the work, and more of the same adds little. Short, sharp and heavy wins over long and easy.

Timing matters too. You build most of your bone mass through childhood and adolescence, and it peaks around your late 20s to early 30s. After that, the trend is gradual loss, which speeds up for women in the years around menopause. Training can't stop the clock, but it can slow the slide and, in many cases, push density back up

Who's at risk of low bone density and osteoporosis

Low bone density isn't just an older person's problem. These groups carry the most risk:

Women around and after menopause. Falling oestrogen accelerates bone loss, often for years before anyone checks.

Older adults. Lower bone density plus reduced strength and balance is the combination that turns a trip into a fracture.

Endurance athletes under fuelling. Relative Energy Deficiency in Sport (RED-S) disrupts hormones and bone turnover. Stress fractures are often the first warning sign, in men and women.

Cyclists and swimmers. Both are low impact, so huge training volumes do little for bone. Plenty of fit riders have scans that would surprise them.

People on certain medications or with chronic conditions. Long-term corticosteroids, some hormone therapies, coeliac disease and rheumatoid arthritis can all affect bone.

If you tick one of these boxes, a conversation with your GP about a DEXA scan is a smart first step. It gives you a baseline to train against.

The best exercise for osteoporosis: lift heavy, land well

For years, people with low bone density were told to stick to gentle walking and light weights for fear of fracture. The research has moved on.

The standout is the LIFTMOR trial, run out of Griffith University on the Gold Coast. Postmenopausal women with low to very low bone mass trained for 8 months, twice a week, 30 minutes a session. The program was supervised heavy lifting at 5 sets of 5 reps above 85% of their one rep max, plus impact work. A comparison group did a low intensity home program.

The heavy lifting group improved bone density at the spine and hip, along with strength and function. Across 101 women, the only adverse event was one minor lower back spasm. A three year follow up found those who kept training kept improving.

That's 60 minutes of training a week. Same women, same age, same starting point: the only real difference was how much load their skeletons were asked to carry.

What that looks like in practice:

Progressive resistance training, 2–3 times a week. Big compound lifts like squats, deadlifts and overhead presses, built up towards genuinely heavy loads.

Impact and jumping. Hops, drop landings, skipping and, for athletes, plyometrics. Matched to your current bone health and joints.

Variety. Multi-directional work, not just the same straight-line movement over and over.

Balance and strength for fall prevention. Bone density is half the fracture story. Not falling is the other half.

Fuel to match the work. Adequate energy, protein, calcium and vitamin D. Training on an empty tank undermines everything above.

The catch: "heavy" has to be earned. LIFTMOR worked because it was closely supervised, with technique built first and load progressed carefully. That's where an exercise physiologist comes in.

How an exercise physiologist in Darlinghurst can help

An Accredited Exercise Physiologist (AEP) is a university qualified allied health professional who prescribes exercise for people with medical conditions, injuries and performance goals. Bone health sits right in that space.

Here's what working with one looks like:

1. Assessment. We look at your scan results, history, medications, strength, balance and how you move, so we know where you're starting.

2. A program built for your skeleton. Exercise selection, loads and impact matched to your bone density and fracture risk, not a generic template.

3. Technique before load. We build the movement patterns first, then progress weight and impact deliberately, the way the evidence did it.

4. Progression and re testing. Strength and function are tracked every block so you can see the work paying off between scans.

5. Working with your team. We liaise with your GP or specialist so training and medical management pull in the same direction.

Our clinic is in Darlinghurst, an easy trip from Surry Hills, Paddington, Potts Point, Woolloomooloo and the Sydney CBD. If getting in is hard, we also run online sessions and mobile visits across Sydney.

Bone density FAQs

Can exercise reverse osteopenia or osteoporosis?

Exercise can increase bone density, and in trials like LIFTMOR it did. How much it moves your scan varies from person to person. It works best alongside whatever medical management your GP or specialist recommends.

Is heavy lifting safe if I have osteoporosis?

For most people, yes, when it's properly assessed, supervised and progressed. Technique comes first, and load builds gradually. If you've had a spinal fracture, your program will be adjusted around it.

How often should I exercise for bone health?

Two to three resistance sessions a week, plus short bouts of impact work, is a solid target for most people. Consistency over months matters more than any single session.

How long does it take to improve bone density?

Bone remodels slowly. Changes on a DEXA scan are usually measured over 12-24 months, though strength and balance often improve within weeks.

Do I need a referral to see an exercise physiologist?

No, you can book directly. A GP referral is needed if you want to use Medicare funding for your sessions.

This article is general information, not personal medical advice. Speak with your GP before starting a new exercise program, especially if you've been diagnosed with osteoporosis.

Sources

Watson et al. (2018), High-Intensity Resistance and Impact Training Improves Bone Mineral Density and Physical Function in Postmenopausal Women With Osteopenia and Osteoporosis: The LIFTMOR Randomized Controlled Trial, Journal of Bone and Mineral Research

LIFTMOR three-year follow-up summary