Found on RunnersWorld.com
How to build endurance gradually and avoid injury.
1. Slow your pace. You’ll save energy for those bonus miles by slowing your pace. You should feel comfortable and able to carry on a conversation. A good rule of thumb: Add 90 seconds to two minutes per mile to your normal pace.
2. Add miles gradually. To keep injuries and burnout at bay, tack on no more than one to one-and-a-half miles at a time. (For marathoners, add no more than two to three miles per week.)
3. Do one long run per week. Pick a day to tackle a new distance (weekends tend to work best for most people). You don’t want to feel rushed to complete your run, so make sure you set aside enough time to get it done at an easy pace. Every three to four weeks, scale back your long run distance to avoid overtraining.
4. Go ahead, take walk breaks. You’ll still reap the endurance benefits of running non-stop. Before you know it, you’ll be able to run from start to finish. (Check out a run-walk guide here.)
5. Fuel the tank. On runs longer than an hour, bring along fuel that’s rich in carbohydrates and electrolytes. To keep your energy level consistent, start fueling about 30 minutes into your run and refuel again every 15 to 20 minutes. Ease into it to train your stomach, and experiment with different products. Learn more about on-the-run nutrition from our Fuel School columnist Pamela Nisevich Bede here.
6. Break it up. Mentally, that is. Segment your run into manageable parts so that you’re not intimidated by the full distance. For instance, a 15-mile run could be thought of as three five-milers.
7. Run a looped route or on a treadmill. Consider running a one- to two-mile loop so you can stay close to fuel, bathrooms or the finish line. You’ll avoid getting stuck far away from home on an out-and-back run or long loop if you need to quit unexpectedly. If you’re on the ‘mill, set the incline to 1% or 2% to better simulate overcoming the wind resistance of running outdoors.
8. Be patient. Building endurance takes time. As Grete Waitz, nine-time winner of the New York City Marathon, put it, “Hurry slowly. Move ahead, but be patient.”