Here’s some advice from Jeff Galloway of Runner’s World
At some point, almost every runner wants to run farther. You complete one mile, you want to try two. You reach three miles, five seems possible. Adding distance to your routine is smart because it improves fitness, builds endurance, and burns calories. Every other week, try running “long”–that is, any distance beyond your usual miles. If you usually run three, start at four miles. Your goal might be to reach an hour, run 10 miles, or work toward a marathon. The following guidelines will help you build miles without undue fatigue or injury.
Taking your speed down a notch or two gives you energy to go longer. Add about two minutes to your usual pace. For example, if you usually run three miles in 30 minutes (10 minutes per mile), expect to run four miles in 48 minutes (12 minutes per mile) or longer.
Adding miles too quickly can lead to burnout and injury. So increase your long run by no more than one to one and half miles at a time.
Run long every other week
This gives your body time to recover, which reduces injury risk.
Take walk breaks
A six-mile run with walk breaks still gives you six miles of endurance. The benefit? More energy for your run and a faster recovery.
The chart below shows a suggested breakdown of running to walking based on your pace.
Typical pace per mile 8:00
Run-walk breakdown 6 min. / 1 min.
Typical pace per mile 9:00
Run-walk breakdown 5 min. / 1 min.
Typical pace per mile 10:00
Run-walk breakdown 4 min. / 1 min.
Typical pace per mile 11:00
Run-walk breakdown 3 min. / 1 min.
Typical pace per mile 12:00
Run-walk breakdown 2 min. / 1 min.
Typical pace per mile 13:00
Run-walk breakdown 1 min. / 1 min.
Typical pace per mile 14:00
Run-walk breakdown 30 sec. / 30 sec.
Typical pace per mile 15:00
Run-walk breakdown 30 sec. / 45 sec.
Dr. Campitelli is a podiatrist in Akron, OH specializing in foot and ankle surgery with an interest and enthusiasm for running as well as helping runners with injuries. For the past several years he has been treating running injuries in patients by fixing their form and transitioning them to minimalist shoes. Having treated runners with all types of injuries through conservative measures with orthotics and shoe gear changes to reconstructive foot and ankle surgery, Dr. Campitelli has brought what works best and is most current to his practice as well as the Akron and Cleveland running communities.