Below is an article I wrote for Vibram USA several years ago to help early adopters transition to running in FiveFingers.  (A more advanced and detailed approach to transitioning is available in my text Running in a Minimalist Shoe available in the iBookstore)

Medical Resource vol. 2:

Transitioning to FiveFingers or a Minimalist Running Shoe

A minimalist shoe is designed to simulate running barefoot and is therefore built with a very low heel and thin sole. These shoes are intended to help you develop your form by allowing your feet and legs to work the way they were intended to. The goal of the shoe is to mimic how you would run if you were barefoot – shorter stride, faster cadence, midfoot/forefoot footstrike.

Switching to a minimalist shoe significantly changes your gait. When our gait changes, we use muscles in a different way to control our foot as it hits the ground. Think of it as starting to run all over again.

We recommend to start out at 10% of what you are currently running and to build on that. It also helps to wear your new shoes around the house to strengthen the muscles in your feet that you are not accustomed to using. Intrinsic muscle strengthening exercises can also help prepare your feet for this new style of running (See Picture.)

There is no doubt that once you bring home your FiveFingers you will be excited to put them on and start running! I would encourage you to let your body adjust by first wearing them sound in your house. If you have the ability to wear them at work or in an environment that allows you to stand for 1-2 hours, this will help.

Some people ask about gradually transitioning from a traditional running shoe to a lower heel height running shoe and then gradually moving down to a minimalist shoe. While this may sound like a good idea, it actually will take longer to do this. Your body will have to adapt to change each time you switch shoes and this change needs to be gradual or it can precipitate injury. In other words, you would have to follow the 10% rule that we have already outlined with each change in heel height. I recommend finding the FiveFingers or minimalist shoe that you wish to begin running in, and then begin the transition process. Most people will start with running .25 miles or 2 minutes in the minimalist shoe, and then putting back on your traditional running shoe to finish your run. It is advised to leave a day rest in between runs ( you can still run the following day in your traditional shoe.) After 2 weeks of this you can then increase to 0.5 miles or 4 minutes. Let your body determine your ability to increase faster. Some people will have the ability to move to 1 mile after 4 weeks. If you are experiencing lower calf pain or dorsal foot pain, slow down the transition rate.

This may seem like a long process, but as you progress into the 2nd and 3rd months you will find your body will allow you to run longer in your minimalist shoe.

I also encourage my patients to begin the process by running completely barefoot on a track or treadmill the first several times so that you can properly adapt to this new gait. FiveFingers do offer the closest sensation to that of running barefoot.

Remember you are basically teaching your body how to run all over again. You will be using muscles that have been relatively inactive during your running previously so they will become sore. This is especially true for the soleous muscle and most importantly the intrinsic muscles of the feet.

Next Friday we will review what happens to the intrinsic foot muscles during this process.

Dr. Campitelli recommends consulting a physician prior to starting any exercise program and the information provided here is not recommended to be advice in place of seeing your doctor for a medical problem.