I've been running fairly regularly for most of the last 14 years, and that's gone pretty well. I do have your book and reference it, both for my use and fellow club members. This past year, though, I did get my first real running injury. It's enough that I'm effectively a beginner again. Something I recall reading, and perhaps the 14 years has rendered it obsolete, or it was never correct, is that the two peak periods for injuries in beginning runners are a) the first 2 weeks and b) between 8-12 weeks. If I remember right, and it's true, the reason for the 8-12 weeks is because that's the length for the aerobic system to adapt, but the muscles are still adapting. Is that 8-12 week injury-prone period true? Is it for that reason? And, if you could, could you mention a reference that I might be able to look up for more details? (I do have Noakes, 4th ed., for instance, and a friend is a member of the ACSM, but he doesn't remember a source on this point.) If it really is something like this, I need to avoid racing in that period. I have too much experience at what my paces used to be, and could force things to an injury this time around.
Reply - Janet
I don't have the actual reference in front of me, but the rate at which different tissue systems adapt varies and the cardiovascular system does seem to adapt a bit faster than the skeletal and connective tissue system does.  Noakes is a great reference but I don't know that I've seen a specific reference stating a certain number of weeks for this or that physiological system.  If you look at cell turnover rates for bone - it kind of points to about a 6-week adaptation cycle, meaning that at about 6 weeks into a training rampup your bones are probably not at their strongest....  As an experienced runner you'd be wise to come back from your injury with a big dose of common sense.  That means gradually building your base mileage, making sure you've dealt with any underlying factors that might be contributing to the inujury you have and making sure you've established a solid foundation of base mileage before dabbling in the speedplay or racing.  Good luck in your come-back!  Janet Hamilton, MA, RCEP, CSCS, RRCA coaching instructor

Im a junior in high school and this past summer I did alot of training with speed and races to train for xc season. I was doing two a days probably 45mpw. I went into the season and I pr-d by over a 1:30 form a 19:50 to 18:08, and for the first month and a half I was running low 18s.The weather got colder and I continued to train hard, well y times started declining and I ended the season running about 19flat. I believe I over trained. Now this summer I am wanting to up mileage t0 60-70mpw just base mileage. I wont be including speed work, or races just some striders here and there. Will this plan be effective to drop a nearly a minute to around 17:15, and will I get my form back like I did at the beginning of the season.
Reply - Janet
Dylan I think you hit the nail on the head - you started your season at a peak and you can't expect to maintain that peak non-stop.  I think your plan to focus more on base mileage in the summer is a sound one. Talk to your coach about when is the appropriate time to transition into a sharpening phase that would include the harder intesnsity stuff.  As you do that - you'll drop your total miles per week a bit to keep from overtraining. Good luck in your senior year!  Janet Hamilton, MA, RCEP, CSCS, RRCA coaching instructor