Picture two people on a Saturday morning. One walks briskly for an hour. The other joins a scrappy game of five-a-side football, sprinting, braking hard and twisting away from defenders. Both go home tired and happy. According to a recent review of 24 studies, only one of them may have given their bones a strong push to build new tissue.
The review comes from a team at Semmelweis University in Budapest and was published in the journal Sports Medicine – Open. It has been making the rounds again in November because it questions two pieces of advice nearly everyone has heard: walk more, and lift weights. Before anyone rearranges their week, it helps to look at what the researchers actually measured. The answer is narrower than the headlines suggest.
What the researchers measured
The team pooled 24 clinical studies covering 1,238 healthy adults. They did not look at bone density scans, which can take months or years to show a change. They looked at blood markers that reflect how actively the body is making new bone. These markers can shift within weeks of starting a training programme, so they make it possible to compare many kinds of exercise quickly. The paper’s title names osteocalcin, one of these markers, as the main result.
The studies were sorted by type of exercise (endurance, resistance or a mix) and also by intensity, frequency and session length. The aim was to find out not only which exercise “works” but what kind of effort bones seem to respond to.
What they found
The strongest responses came from sports built on explosive effort: short sprints, hard stops, quick changes of direction and turns. Recreational football and handball stood out, with increases of up to 45 to 46 percent in the blood markers linked to bone formation. Walking, step aerobics and ordinary gym resistance work produced weaker effects.
The result that surprised the authors most was about weights. First author Viktória Barna said resistance training had no significant effect on the bone markers, even though several professional guidelines recommend it for bone health. Walking and jogging, at low or moderate intensity, showed no meaningful long-term effect on these markers either.
The researchers’ explanation is mechanical. Bone responds to force, and the sudden, uneven loads of a fast sport may be a stronger signal than the steady, repeated loads of a walk. A 2023 analysis in the same journal fits that picture loosely: it found that a single long, steady running session of 60 to 120 minutes did not change two common bone markers in young healthy men.
What the study does not show
Start with the obvious gap. The markers are a short-term signal, not bone strength. The review did not measure bone mineral density or fractures, and the researchers say as much. A blood marker rising over a few weeks does not prove that someone’s bones will be stronger in ten years.
The people studied were healthy adults. Nothing here tells us how someone with osteoporosis, a past fracture, or a frail older person would respond, and for those groups a fast, twisting sport could carry real risk. The study authors themselves advise people with heart, joint or metabolic conditions, and anyone with osteoporosis, to speak with a doctor or sports medicine specialist before taking up anything more demanding.
There is also the question of how much weight the headline number can carry. The press material does not say how many studies sat behind each sport, and I could not open the full paper to check. Treat “up to 45 to 46 percent” as the top of a range, not what you should expect from a weekend kickabout.
And the review does not say walking is pointless. The authors state that lower-intensity activity keeps its health benefits. The World Health Organization’s fact sheet on physical activity reports that people who are insufficiently active have a 20 to 30 percent higher risk of death than those who are active enough, and that any amount of movement is better than none. The WHO also links regular physical activity with fewer falls in older adults, which matters a great deal for broken bones, whatever it does to a blood marker.
How it fits with existing advice
The Bone Health & Osteoporosis Foundation already sorts exercise into groups: high-impact weight-bearing activity such as jogging, skipping rope, tennis, basketball and soccer; lower-impact weight-bearing activity such as stair machines and low-impact aerobics; strength training; and balance work such as yoga. It points out that cycling and swimming are not weight-bearing, so they do less for bones. It also tells people who cannot manage high-impact exercise to choose the lower-impact options, and to check with their provider about which group suits them.
Seen that way, the Budapest review does not overturn the guidance. It adds weight to a point that is easy to miss: “weight-bearing” comes in strengths, and the top end of the range may matter more than a pleasant daily stroll. WHO’s own guidance still recommends at least 150 minutes of moderate activity a week and says muscle strengthening benefits everyone.
Putting it to use, sensibly
If you are healthy and already walk every day, there is no reason to stop. The more interesting question is whether you can add a little bounce to it. Short bursts of faster walking are a gentle starting point, and our explainer on Japanese interval walking shows one simple way to structure them. From there, people with healthy joints sometimes add stair climbing, skipping, dance classes, or a weekly game of badminton, basketball or football with friends.
Go slowly. Jumping from a walk to hard sprinting and cutting is how people pull muscles and twist knees. If you have been inactive for a long time, it also makes sense to build your general fitness first, and our piece on strengthening your heart naturally is a reasonable place to begin.
Keep the strength sessions too. The review looked at one bone marker, and strength training has other jobs: it supports balance, and it protects against falls. Diet still plays a part as well. The Foundation notes that exercise does more for bones when calcium and vitamin D are adequate, and if you are unsure about your own levels, our article on vitamin D deficiency, its signs and sources covers the basics.
One more thing worth remembering is that most of the people reading this are not elite athletes and do not need to become them. A game you enjoy enough to repeat every week will do more for your bones than a punishing routine you quit after a fortnight.
This article is for general information only and is not medical advice. If you have osteoporosis, a heart or joint condition, or any health concern, speak to your doctor before changing your exercise routine.