Many people run to stay in shape. Some may even incorporate long-distance running into their routines. But a recent study shows that marathon running may do more harm than good.
People that run long distances may experience exhaustion. They may damage their muscles leading to long-term pain and injuries. There is also limited knowledge on how marathon running can affect different muscles in the feet.
The Study
The study was led by Professor Mako Fukano from the Shibaura Institute of Technology (SIT). He and his team of researchers looked at how marathon participation affects different foot muscles. The results were published online in the Scandinavian Journal of Medicine & Science in Sports on April 27, 2023.
Researchers looked at 22 college track and field club members who ran 2-3 times a week and had registered for the Mt. Fuji International Marathon in 2019 or 2021. They used magnetic resonance imaging (MRI) to measure the transverse relaxation time (T2) of the intrinsic foot muscles, which stabilize the arch of the foot, and the extrinsic foot muscles which are in the lower leg where the foot connects to the ankle.
T2 measures muscle damage. The measurement was taken before the marathon and 1, 3, and 8 days after completing the marathon for the following muscles:
Intrinsic muscles:
- Abductor hallucis (ABH)
- Flexor Digitorum Brevis (FDB)
- Quadratus Plantae (QP)
Extrinsic muscles:
- Flexor Digitorum Longus (FDL)
- Tibalis posterior (TP)
- Flexor Hallucis Longus (FHL)
The team also measured the height of the longitudinal foot arch to determine changes.
Researchers noted significant changes in the QP, FDL, TP, and FHL one day after the marathon which continued to fluctuate over the next days. However, there were no significant changes in the ABH and FDB muscles. They also found a decrease in the longitudinal foot arch directly related to the changes in the FDL and FHL.
What Does it Mean?
The research shows that different foot muscles are affected differently during long-distance running. It also finds that all three extrinsic foot muscles showed signs of damage as compared to just one intrinsic foot muscle. It reveals that outer foot muscles are more prone to running-related damage than inner foot muscles.
Professor Fukano explains that the pressure put on the ankle joint during long-distance running is contributing to the damage, an outcome consistent with other study findings. The QP is the only inner muscle to experience damage which is likely due to its connection with the outer foot muscles FDL and FHL. The relationship between FDL and FHL damage and the reduced longitudinal foot arch suggests that the damage to these muscles could contribute to a decrease in foot arch height.
Fukano states that the study’s results could be useful to runners and sports professionals. It can help them plan effective strategies for recovery that reduce fatigue and damage. It can prevent injuries and improve fitness in runners.
