The way to determine when to increase your distance is by observing how long you can hold your form together. As you become able to hold your core engagement and, therefore, your form for longer and longer periods during the run, then it's time to add a few minutes the next time you run.
Anytime you add something to your running program, whether it is distance or time, new terrain such as hills or the number of runs per week is an upgrade. Upgrades are an important way of building your running program because each addition causes the body to adapt to the new load, which increases your level of conditioning.
Be careful though. The same stresses that in moderation cause the body to adapt and grow stronger can cause injury if overdone. This can put you into an over-reached or over-trained state, where your body cannot keep up with the adaptations, and you stop improving, get overtired or even injured.
Using the principle of gradual progress you can build your program carefully by adding no more than two upgrades per week. Here are some additional guidelines for upgrading your program:
- Don't add more than 15 to 30 seconds to an interval.
- Don't add more than 15 minutes (or 10 percent additional mileage, whichever is less) to your long run each week.
- If you increase the number of intervals per session, run the first ones slightly slower.
- If you increase the speed of your intervals, decrease the number of intervals in your session, then gradually build back up to the original number while you maintain your new speed.
- If you happen to have a great day and end up running farther or faster than usual, don't do anymore upgrades that week. Save them for next week.
Intervals, as defined in the ChiRunning method, are: a series of accelerations based on increased lean and increased relaxation (most importantly pelvic rotation) resulting in a longer stride, while maintaining a steady cadence.
The second title to the ChiRunning book says: A Revolutionary Approach to Effortless, Injury-free Running, which is a pretty big statement. But turning your running into a "practice" with the goal of becoming effortless means that every time you go out for a run, you're working on what you can do to create better results by doing less. That's the real work!