The 20-year study of almost 300 children around Australia has found that those who did lots of jumping, running, and skipping had more cartilage in their knees than those who were sedentary.
It is estimated about 3 million Australians will be affected by osteoarthritis by 2050.
The irreversible disease is caused by cartilage breakdown and is most common in the knee joint.
Researchers at Hobart’s Menzies Institute have found physical activity during childhood increases the amount of cartilage in the knee, helping prevent the onset of osteoarthritis later in life.
The institute’s Professor Graeme Jones says high impact activities were more effective in building strong knees than gentler activities like walking.
“The bones adapt to that extra physical load and because cartilage basically covers the end of the bone, if your bone gets larger, you’ll grow more cartilage over the end of that bone,” he said.
“So that then gives you a knee that’s able to adapt better in later life and should last longer because you’ve got to lose a fair bit of cartilage before you get end-stage arthritis.
“It’s really the first study that has shown that what you do in childhood can have an effect on joint health.”
The ideal age for children to be developing their knee strength is before they hit puberty but it is still possible for adults to grow new cartilage.
“It used to be thought that you couldn’t change the amount of cartilage you had after 18 but it now looks like it’s gone up to about 45.”
Professor Jones says losing weight may also help adults slow down cartilage loss.
The study compared information from 1985 to knee scans taken over the past three years.