12/16/01
A runner can improve for up to 10 years, regardless of the age at which s/he starts. (For an in depth study of the why's and wherefore's of this, see http://home.hia.no/~stephens/, which is an excellent website for Masters.) Of course, this assumes that a runner trains consistently. If s/he is inconsistent (start/stop or with no plan) so that s/he is always restarting, the total period of improvement might be extended, but the eventual level reached might be lower.
Progress is best achieved through a long term program that includes a balance of speedwork, endurance, strength, and rest...that is, long runs and high mileage with speed training, hill training, weight training and scheduled rest periods. It should be based on a plan...and the longer term the plan, the better.
It's best to follow a multi-year plan to optimize progress. I suggest the type of plan I like to follow...alternate marathon and 10k seasons. I prefer spring 10k and fall marathon programs, but the reverse works just as well. You can even fit three programs into a year with shorter "racing" phases following the training cycles.
Although both 10k and marathon programs include long runs and speedwork, they are different. The marathon program emphasizes mileage and AT speed training, while not ignoring speed and running economy. The 10k program focuses more on faster speedwork (VO2max and running economy training)since 10k's are run somewhat below AT, with somewhat less mileage. They complement each other. The benefits of each feeds the other, which enables you to "stair-step" your way to higher levels.
This long term plan approach is simply taking the "hard-easy" concept of training to a "macro level"...what's "hard" in a 10k program is "easy" in a marathon program, and vice versa. So, both body and mind get an extended break from each form of stress while still being challenged by the other. I think this is preferable to year round marathon training.
Concerning "rest." To make progress, you have to challenge yourself to move to a higher level, then rest so your body can consolidate at the higher level. Rest is an important part of any training program and it should be planned. The best way to schedule rest is the hard/easy approach...that doesn't mean just day-to-day or week-to-week. It also means season-by-season. Alternating 10k and marathon seasons is an excellent way to build rest into a macro-plan. But, I like to go even beyond that. I suggest planning extended rest periods between the seasons. Specifically, 2-4 weeks of R&R between each 10k and marathon season. These breaks don't mean no running, but they do mean a big cut in mileage, no hard runs or racing, no long runs, etc. These are the times you recharge your batteries for the next 4-6 month "mini-cycle" within the macro cycle. This is even the time to treat yourself to a big banana split, holiday dinner, or New Year's Eve party...great for mental recovery. :)
One simple way to go about structuring progress is to get a copy of Bob Glover's book, "The Competitive Runner's Handbook", which is written for runners of all levels who want to improve. Especially study the 10k and marathon chapters. Choose the level of training schedule that best defines where you are now. Then start a long term plan to run each of the 2 programs every year, starting at your current level and increasing the level each year based on the progress you make.
My basic points are:
1) Any beginning runner can look forward to several years of improvement.
2) Reaching your maximum potential will take what I call the 3 P's of running.....Patience, Perseverence, and a Plan.
3) It will also take a lot of hard work and a little luck in avoiding injuries.