You will have to tailor your regiment to fit your needs. In losing 105 pounds I discovered the key to elite performance training is change. P90X is so successful because it's constantly changing the pace, methods, type, intensity of the workout. Every time you do a P90X session your body get's it's @$$ kicked. I have not ever done P90X but I've observed it and seen the merrits. Abstracting the concepts into my own exercise I have to admit the science is sound. Distance running is highly static and predictable. If possible very your terrain. Interlace interval sprints of different intensity, frequency and duration (in the same session). Sometimes rest for a minute between bursts and others rest (meaning keep running just at a recovery pace) longer. Just make sure that longer rests are followed by longer, higher intensity or a group of short, highly, intense bursts at randomized periods. I think that if you don't understand how to approach this on your own I'd recommend two courses of action. One consult a trainer (expensive). Two go to an elite running store in your area, try on shoes and talk to the employees. See what they are doing. Additionally, hit your outdoor exercise areas and spot elite athletes. If possible contact them and request a few minutes of their time to get tips and suggestions. Maybe, if it seems appropriate, ask if you can tag along for one of their sessions. I think there's tons that you *CAN* do. But what I want to conclude with is *JUST* - *DO* - *IT* and don't over-think it. :-\ The frog has spoken. Ribbit();
There have been joys too great to be described in words, and there have been griefs upon which I have not dared to dwell, and with these in mind I say, climb if you will, but remember that courage and strength are naught without prudence, and that a momentary negligence may destroy the happiness of a lifetime. Do nothing in haste, look well to each step, and from the beginning think what may be the end. - Edward Whymper Climb On!