Your feet may not thank you for those marathon feats.
As a much younger man, your Back Page correspondent was a moderately keen runner and occasional participant in the odd half-marathon or two.
These days, however, running would only be considered an exercise option if being pursued by the bear from The Revenant. Even then, temperamental knees and dodgy arches would ensure there was only one winner of that lopsided contest.
Which brings us to a new study by Japanese researchers, published last month in the Scandinavian Journal of Medicine & Science in Sports, which appears to be quite interesting to both former and current pavement pounders.
While the cardiovascular benefits of long-distance running are undoubted, little is known of the impact of routinely subjecting oneself to a 42km endurance test on other parts of the body, in particular the feet.
So this study set out to explore the damaging effects of full marathon running on intrinsic and extrinsic foot muscles, and the association with changes in the longitudinal foot arch.
Intrinsic muscles originate and insert within the foot while extrinsic muscles originate in the lower leg and insert into the foot via the ankle. Both muscle groups work to stabilise the medial (inner) longitudinal arch of the foot.
The researchers recruited 22 college runners from track and field clubs that ran at least two to three times a week and had registered for a full marathon race at the Mount Fuji International Marathon, either in 2019 or 2021.
They used MRI to measure foot muscle damage in the runners before the marathon and one, three and eight days after the race.
What they found was that marathon running had a more damaging effect on the extrinsic muscle groups than the intrinsic ones, and that the foot arch height ratio decreased from before the race to afterwards.
This damage to extrinsic foot muscles reflected the extensive pressure borne by the ankle joint while running for long distances as compared with the rest of the foot, the study authors said, and that this extrinsic damage could be a factor in lowering the foot arch height.
“Since more people are now running for their fitness, our findings can provide runners and sports professionals insights on planning better recovery strategies focusing on muscle fatigue and damage to prevent running-related injuries and also improve runners’ conditioning,” the authors concluded.
And while this knowledge may not help you outrun a bear, it may help you outrun the person next to you, and that could make all the difference.
Sending story tips to firstname.lastname@example.org can improve your fitness without buggering up your feet.