Excess weight: the importance of weight loss
Many chronic foot problems (ex. tendonitis, stress fractures, arthritis, etc.) are caused by, or aggravated by, increased force absorbed by the foot during each step. The foot absorbs 2-3 times body weight during each step while walking and 4-5 times body weight during running or other “high impact” activities. These forces are many times body weight because the foot acts like a lever (when the heel comes off the ground) to magnify the forces that the structures in the foot are subject to.
To minimize these forces and thereby hopefully decrease symptoms or slow the progression of chronic injuries there are a few things that can be done. Comfort shoes can help provide shock-absorbing capacity and allow for the smooth dispersion of forces up the leg. Walking and running on softer surfaces (i.e avoiding concrete and pavement) can also help to limit the forces that the structures of the feet are exposed to. However, the most important is to maintain an optimal body weight!
What is optimal body weight?
Optimal body weight varies from person to person. However, in general a patient should strive to maintain a normal Body Mass Index (BMI) which is between 18.5 and 25. Patients with a BMI > 30 are considered obese, whereas patients with a BMI > 40 are considered morbidly obese. Lowering your BMI into the normal range can often have a dramatic effect on foot symptoms!
Strategies for Weight Loss!
Weight Loss requires burning more calories than are taken in by eating. Therefore an appropriate diet to limit calories combined with a regular exercise program to burn off calories is critical for weight loss. You should strive to work out for at least 20-30 minutes 4 times per week.
An appropriate diet would include regular small meals which include fruits and/or vegetables, combined with the elimination of high calorie deserts, snacks, and drinks.
Many common forms of exercise such as walking and running are NOT appropriate for patients with serious foot problems because they will increase the loading through the foot and thereby increase symptoms. Regular “low impact” exercises such as cycling, swimming, or water aerobics are preferable:
Use of an exercise bike is an excellent way to burn off calories without excessively stressing your feet. When using an exercise bike generally about 50% or your body weight goes through your feet (unless you are standing “out of the saddle”) which is substantially less than the 4-5x body experienced by the feet when running. In general a low resistance setting and a high RPM is the best way to burn off calories without excessively loading your feet. Care must be taken to ensure that your seat height is positioned correctly as a poorly positioned seat can lead to knee symptoms. As a generalization most novice cyclist have their seats positioned too low. Your knee should be slightly bent when you toe is on the pedal at the bottom of the pedal stroke.
Swimming is an excellent way to burn off calories without putting much strain on the feet. If kicking in the pool aggravates your foot condition you may consider swimming with a Pull-Buoy between your legs to eliminate the use of your feet altogether.
Placing a life vest on and getting in a swimming pool allows an individual to perform a variety of exercises aimed at stretching strengthening and building aerobic fitness. Simply “running in the pool” can be an excellent form of exercise.
Edited August 14th, 2009