Cycling and Your Feet
The foot is the contact point with the cycling pedal. Because of this, foot problems are not uncommon to cyclists. Most of these problems can be easily fixed.
In a 2003 study, shoes with carbon-fiber soles were shown to induce more stress under the forefoot. If you are susceptible to a common burning feeling, known as neuromas, or "hotfoot" (pinched nerves near the third and fourth toes), and/or have minimal fat padding, then consider Nylon soles. Wider forefoot configuration, particularly with shoes made in the Far East, help avoid forefoot compression. Moving the cleat back behind the ball of your foot also reduces the force (see illustrations below).
Cleat in Mid Position
Cleat Moved Back
Pedals with a wider platform distribute the force better than smaller pedals. Regardless of the platform width, you may still get some discomfort if you cycle far enough. In fact, just like with running, the more you cycle, the more the fat padding under the ball of your foot wears thin. Then it may be time to consider seeing a podiatrist or other specialist that deals with cyclists' foot problems.
Biomechanical abnormalities, such as a shorter (or longer) limb, can be addressed with an extra insole in the forefoot (up to 1/4 inch if you have enough volume in the shoe), adding washers/shims between the cleat and the shoe or moving the cleat back on the longer leg's shoe. Foot orthoses with a forefoot extension can help control excessive internal leg rotation, which can cause knee pain (patello-femoral syndrome/chondromalacia). (See below.)
Keep in mind that a seat positioned too low or high, and cycling with too high a gear, can also contribute to knee pain.
Achilles tendon problems are not uncommon with cyclists, particularly those covering a lot of mileage. The covering of the Achilles, known as the paratenon, can get inflamed from the continuous friction. Physical therapy, staying in the saddle and using lower gears can help. Sometime surgery is needed and is very helpful.
Cycling in the winter or rain can be made more pleasant by placing your shoes over a heater vent prior to rides, placing extra insoles or foil to cover that ubiquitous hole in the bottom of the forefoot of most shoes, and using wool-blend (Smartwool™) or Thermax ™ socks. Various shoe covers that enclose the toes and even the whole shoe are very helpful.