What effect does running your first marathon have on your hips?
Published July 2021 in the Orthopaedic Journal of Sports Medicine
Our second hip study was also based on the 2019 Richmond Marathon. To date, no studies had focused on MRI of the hips of marathoners, despite the popularity and injury risks of marathon running. 28 runners participated – all first-time marathoners in their 30s, with no known hip injuries.
Long-distance running is very popular, with more than 30 million people annually participating in marathons across the globe and many of them being novice marathon runners. The repetitive loading during running is thought to place a high amount of stress on musculoskeletal joint structures, particularly on the articular cartilage and subchondral bone. The vertical forces exerted by running can reach up to 8 times the body weight at the knee joint and 5 times the body weight at the hip joints. A high dose of running, asin a marathon (42 km), has anecdotally been associated with an increased risk of osteoarthritis, although evidence is inconclusive.
Previous studies have used MRI to focus on the effect of marathon running on knee joints and found that the high-impact forces are actually well tolerated in runners with no pre-existing injuries. However, limited research has been done on hips.
The objective of this study was to better understand the effects of a 4-month beginner training program for a marathon run, plus the race itself, on the hip joints and muscles of 28 first-time marathon runners, using high-resolution MRI before and after the period of training and the event itself.
Our hypothesis was that beginner long-distance runners would show no pathological findings on their MRI scans after their first marathon run and therefore marathon running would not be detrimental to their hips
Our findings suggest that training for and running a marathon does not induce damage or acute changes in the hips of runners.
In short…
The study
Our objective was to assess hip health before and after a group of runners trained for and completed a marathon.
The study was a collaboration with organisers of Richmond Runfest, which helped us source participants in 2019.
We recruited 28 participants who met the requirements: to be aged 18+, have no known hip problems, and to have never run a marathon.
They underwent MRI scans of both hips 16 weeks before the date of the marathon and two weeks after the event.
21 runners completed the standardised, 4 month–long training programme and the marathon; 7 runners did not complete the training or the marathon.
What we found
Abnormalities on MRI scans before training were found in 90% participants, and there were only two new abnormalities on the MRI scans after the maraton. These were not associated with symptoms or reduced hip function.
Only 1 participant did not finish the training because of hip symptoms; this participant had no abnormality on the second MRI scan, and their symptoms rapidly resolved.
The presence of abnormalities, which included labral tears, bone marrow oedema and abnormalities to the tendons and ligaments, did not affect marathon finishing times.
The differences in pretraining running experience among participants did not affect MRI findings or running performance.
There were very few changes between MRI scan 1 and 2.
What it means
This research is an important step in understanding the effect of high doses of running on the hip joints. Previous research in this area is very limited.
Our results suggest that marathon running does not induce any acute changes between the pre- and postmarathon hip MRI scans of first-time marathon runners with no previous hip problems or known injuries.
Running a single marathon is therefor not associated with damage - which is of great importance given the rising concerns relating running with hip injuries and arthritis.
Our study supports current evidence showing lack of hip arthritis in marathon runners. Other studies have shown that an increased number of marathons may be associated with decreased joint pain. This may be because of muscle strengthening during training, which can potentially reduce the load effect on the joints and thus decrease the risk of injury.
The joints themselves may gradually develop adaptation mechanisms over time, i.e. joints of runners may be able to adapt to tolerate the high-impact forces exerted during running to lower the risk of joint damage.
