Is running a marathon actually good for you?
New research adds clarity to a long-standing question on health, joints and bones
Is running 26.2 miles good for you, or are we pushing the body too far?
A recent article in the Financial Times revisited a simple question that’s been asked many times before: is marathon running actually safe? It looked at arguments for and against, with contributions from Exercise for Science. Below we summarise the key points and what the latest research suggests.
The health gains
There’s strong evidence that training for a marathon can bring real health benefits. In a University College London study of first-time marathon runners, participants saw meaningful improvements in blood pressure and flexibility of their arteries — changes that effectively reversed signs of arterial ageing by around four years. Cardiologist Anish Bhuva, who co-led the study, noted that the biggest improvements were seen in older runners and those with higher blood pressure at the start.
The research also highlights effects beyond the heart. As Professor Hart explains, the kneecap has the thickest cartilage in the body precisely because it regularly takes high load. In Exercise for Science MRI studies, runners who followed a four-month marathon training plan showed no signs of joint deterioration — and in some cases showed small improvements. As Alister puts it, “bones need impact - they strengthen through it”.
Psychological and mental effects are also worth noting. Training for a marathon gives structure to people’s weeks, reduces unhelpful rumination, and helps build social connection through shared effort. Some research even suggests a link between higher fitness and faster information processing in the brain.
“Bones need impact — they strengthen through it.”
The risks
Running a marathon carries risks and is not automatically healthy for everyone. In the FT article, cardiologist Carl Lavie pointed out that the level of exercise most closely associated with the greatest heart benefit is far lower than marathon training — around 30 to 40 minutes a day.
Pushing beyond about ten hours of training a week may raise the chances of certain heart rhythm changes or increases in hardened arteries. For middle-aged runners preparing for marathons or ultras, a screening test such as an ECG or coronary calcium score might help check for hidden heart disease before training ramps up.
There are also musculoskeletal considerations. Studies of ultra-endurance athletes suggest that up to half of participants report issues such as temporary swelling of cartilage or soft-tissue changes. Researcher Guillaume Millet highlighted that extreme distances place athletes near the edge of what the body can adapt to, and that fatigue, lack of recovery and repetitive strain all contribute to higher injury risk.
Evolutionary biologist Daniel Lieberman, quoted in the article, reminded readers that while humans evolved as endurance movers, our ancestors did so in varied ways — with walking, running, carrying and lifting — not repetitive miles on hard pavement.
A balanced view
Most people will experience some injury at one time or another during marathon training. Around 90% of runners report issues at some point, most often around the kneecap when movement patterns aren’t well aligned. Simple conditioning can help reduce those risks.
Strength drills such as glute bridges, and cross-training activities such as cycling help keep the kneecap moving smoothly and reduce strain on other tissues. The focus, Alister suggests, should be on training that the body can sustain over time rather than pushing ever harder.
So, marathon training brings real benefits for the heart, for psychological wellbeing and cellular health for many people. But it also carries risks when the body is overloaded or when training is not well planned. Humans evolved to move, but not necessarily to run 26.2 miles on tarmac.
For most people, the healthiest approach is to run regularly, include other forms of movement, build in strength work, and understand how the body responds to training.