Does running cause osteoarthritis?
Recreational running probably does not cause osteoarthritis and is actually associated with less osteoarthritis than a sedentary lifestyle. The real risk lies in previous joint injuries, a high BMI and elite-level training loads.
The idea that running causes osteoarthritis is not supported by the available studies. The vast majority of clinical research finds no link between running and cartilage breakdown in the hip or knee. Overuse injuries to muscles and tendons can occur, but cartilage damage caused by running has not been demonstrated1.
Recreational runners actually have less osteoarthritis than people who do not exercise at all. In one comparative study, 3.5% of recreational runners had hip or knee osteoarthritis, compared with 10.2% of non-exercisers. The difference just fell short of statistical significance, but the direction is clear. People who have been running for fewer than 15 years even have a significantly lower risk of osteoarthritis than non-runners2.
At the elite level, the picture is different. Among elite runners, the prevalence of hip and knee osteoarthritis was 13.3%, nearly four times as high as in recreational runners. The extreme training load therefore does appear to send a risk signal. However, this applies specifically to competitive sport, not to the average runner2.
Mileage, marathons, years of experience and pace hardly matter on their own. Among 3,804 marathon runners, none of those training characteristics proved to be a significant predictor of osteoarthritis. Clear risk factors that did emerge were: older age, higher BMI, hereditary predisposition, and above all a previous knee or hip injury or surgery3. If a joint is already damaged, running can increase the risk.
For the everyday runner, the conclusion is encouraging. Moderate running is probably not harmful to your joints4,5. If you have no history of joint problems, a healthy weight, and run recreationally, you have no reason to fear osteoarthritis. If you have previously had knee or hip complaints, discuss this with a doctor or physiotherapist before significantly increasing your training load.
All claims are based on associative research: cross-sectional studies, surveys and literature reviews. No randomised controlled trials are available, so cause and effect have not been established. Selection bias may play a role: people with joint complaints tend to stop running earlier, which could make the figures for active runners look more favourable than they really are.
Can intense exercise actually make you age faster?
Extremely high levels of exercise can increase cardiac damage and oxidative stress, but telomere studies actually show positive associations in active people. Build high training loads up gradually and give your body sufficient time to recover.
Is walking enough, or do I really need to do strength training too?
Walking is good, but strength training adds something walking cannot: preserving muscle mass, strengthening bones and keeping your metabolism in shape. Even half an hour of muscle-strengthening exercises per week makes a measurable difference.
Does walking do enough to maintain your muscles?
Walking alone is not enough to maintain muscle as you age. Add strength training and ensure adequate protein intake for the best results.
Can you exercise too much?
Training too much without sufficient recovery can lead to overtraining syndrome, with demonstrable harm to your performance, hormonal balance, immune system and mental health. Take signals such as persistent fatigue and declining performance seriously.
How often and how hard should I strength train?
Start with 2 to 3 training days per week, sets of 8 to 12 repetitions close to your maximum, and increase the weight as soon as you can add extra repetitions. This approach demonstrably builds both strength and muscle mass at every level.
How quickly do I lose fitness if I stop exercising for a while?
Your aerobic endurance declines quickly: a measurable difference is already present after 10 days. If you maintain your intensity when training less, you can limit the loss considerably.