Bone Health Across a Lifetime: What to Do at 25, 45 and 65

Bone is living tissue — roughly 10% of your skeleton is torn down and rebuilt every year. That cuts both ways: bad habits strip it, and loading builds it. Here is what actually changes decade by decade, and what to do in each one.

What happens to bone over a lifetime

You hit peak bone mass between 25 and 30. About 90% of it is banked by age 18-20, which makes your teens the single most valuable window you will ever get. After 40 you lose roughly 0.5-1% of bone density per year. In women, the first 5-7 years after menopause push that to 2-3% per year as estrogen drops — the biggest single jump in fracture risk in anyone's life.

Men are not exempt, just delayed: losses accelerate after 65-70. Around 20% of all hip fractures happen to men, and their mortality in the first year after a hip fracture is higher than women's.

Training: the only thing that actually builds bone

Bone responds to load, not to movement in general. Swimming and cycling are excellent for your heart but send almost no signal to bone; walking sends a weak one. You need force.

Strength work

• 2-3 sessions per week, 45-60 minutes each.
• Multi-joint lifts: squat, deadlift, lunge, overhead press, row, pull-up.
• 3-5 sets of 5-8 reps at 75-85% of your 1RM. Light 15-20 rep sets build endurance, but bone barely notices them.
• Progression is not optional: once you hit the top of the rep range in every set, add 2.5-5 kg (5-10 lb) next session.

Impact work

• 10-20 jumps, 3-5 times per week — vertical jumps, hops in place, two-foot drop landings from a 20-30 cm step.
• Rest 10-15 seconds between jumps. Bone resets in that gap, so the next landing counts as a fresh signal. Twenty jumps back to back do less than twenty spaced out.
• The whole thing takes 2-3 minutes. If you already have diagnosed osteoporosis or a fracture history, skip this until you have talked to a doctor.

Bone does not ask how long you moved. It asks how hard you loaded it.

Balance — after 60

Past 60, half the benefit comes from simply not falling. Concretely: single-leg stands, 30 seconds per side, twice a day; heel-to-toe walking for 10 metres; sit-to-stand from a chair without using your hands, 10 reps, 2-3 sets. Structured balance and tai chi programs cut falls by 20-30%.

Nutrition: three numbers worth memorising

• Calcium: 1000 mg per day for adults, 1200 mg for women over 50 and men over 70. Rough guide: 250 ml of milk ≈ 300 mg, 30 g of hard cheese ≈ 200 mg, 200 g of yoghurt ≈ 250 mg, 100 g of tinned sardines with bones ≈ 350 mg, a cup of cooked kale ≈ 180 mg. Food first whenever you can.
• Vitamin D: 800-1000 IU per day for most people at northern latitudes, where skin makes essentially none from October to March. Get a blood level checked; aim above 30 ng/ml (75 nmol/L).
• Protein: 1.2-1.6 g per kg of bodyweight per day. Roughly half the volume of bone is collagen, which is protein. In older adults, too little protein damages bone as much as too little calcium.

Magnesium (300-400 mg) and vitamin K2 help at the margins, but they are a side story if the three above are not handled.

What actively strips bone

• Smoking — smokers carry 1.5-2 times the hip fracture risk.
• More than 2 drinks a day — alcohol directly interferes with the cells that build bone.
• BMI under 18.5 and chronic energy deficit. In women training hard and eating too little, missing periods for 3 months or more means bone is actively being lost. That is an alarm, not a sign of good condition.
• Long-term corticosteroids — for example prednisone at 5 mg or more for longer than 3 months.
• More than 8 hours of sitting a day with no loading anywhere in it.

When to see a doctor

Ask for a DXA scan or a conversation with your GP if:

• you are a woman over 65 or a man over 70 — that is routine screening, with no symptoms needed;
• you broke a bone after age 50 from a fall at standing height (a low-trauma fracture);
• you have lost more than 3-4 cm of height, or notice rounding of the upper back;
• a parent had a hip fracture;
• you take corticosteroids, thyroid medication, anti-epileptics, or hormone therapy for breast or prostate cancer;
• you had early menopause (before 45), coeliac disease, inflammatory bowel disease, hyperthyroidism, or bariatric surgery.

Sudden severe back pain with no injury, that does not settle and comes with height loss, should be looked at within days — it can be a vertebral compression fracture.

The short version

• Peak bone mass lands around 25-30; after 40 you lose 0.5-1% a year, and women lose 2-3% a year for the first 5-7 years after menopause.
• Strength training 2-3 times a week, 3-5 sets of 5-8 reps at 75-85% 1RM, is the only reliable way to build bone.
• Add 10-20 jumps 3-5 times a week with 10-15 seconds between them — 2-3 minutes total.
• Calcium 1000-1200 mg, vitamin D 800-1000 IU, protein 1.2-1.6 g/kg daily.
• DXA at 65 (women) or 70 (men), and immediately after any low-trauma fracture past 50.