This article is talking about non-specific soreness in the sole of the feet. This is not Plantar Fasciitis, nor issues where there is pain in a particular tendon, bone or joint.
There are a number of possible causes of sore feet.
- Low Cadence If your Cadence is low, you will spend longer in the air, which requires more vertical movement and greater landing forces. Low Cadence will result in added stress to the body, which can result in sore feet as well as knee and hip problems. Correct Cadence is critical for running.
- Too much shoe Studies have shown that counter intuitively, the more padded your Shoes, the higher the landing impact. More expensive Shoes with more padding are therefore likely to increase the risk of sore feet rather than help. See The Science of Running Shoes for more details.
- Too little shoe At the other end of the spectrum, running with minimal Shoes can also result in sore feet. This is not due to impact, but rather caused by stepping on uneven surface. If you imagine stepping on a stone in bare feet, you can see how this will hurt the feet. This tends to be a surface dependent problem, with manmade gravel trails as one of the worst. Balancing too much and too little shoe is difficult on some surfaces. A minimalist shoe like the Modified Nike Free works well on asphalt or natural trails, but struggles on rough gravel.
- Foot slap If you can hear your feet slap the ground when they land, the force that is causing the sound is also likely to damage your soles. Higher Cadence and more minimalist Shoes should help reduce this, but if foot slap remains, get someone to watch you run. They may be able to suggest the cause of the problem.
- Too Much Too Soon A sudden increase in mileage can result in all sorts of Overuse issues, including sore feet. Doing Too Much Too Soon is especially dangerous when swapping to minimalist footwear, as it takes time to build up the required strength. Longer races can also cause sore feet.
- Time on feet Spending longer periods of time on your feet, whether or not you are running. If you have a job where you stand, or if you go sightseeing after a race, this can trigger sore feet.
The cure for sore feet is to treat the underlying cause, but there are also some possible ways of alleviating the symptoms.
- Stay off your feet If your feet are sore, try to avoid spending more time standing, or walking.
- Ice Icing your feet can be initially painful, but can bring relief even if your feet are not swollen.
- Massage Massaging the feet may help recovery, but more importantly, it will help identify any more significant issues.
- Compression Using compression socks may help reduce the pain.
- Foot Baths Bathing your feet in salt or Epsom salts is a traditional cure for sore feet.
- Chemical Cooling Using menthol, eucalyptus or 'icy-hot' may bring symptomatic relief, but use with caution as they can also irritate the skin.
- Calf TLC Foot problems can be triggered by issues in the calves. If a muscle in the calf is in spasm, it can cause symptoms in the tendons in the feet. Massaging and icing your calves is a low risk option for helping your feet.
- Review your log Your training log should help identify if you have increased your mileage. A good training log will have reports to simplify this. See The importance of a training log for more details.