Aerobic exercise is 19 times more economical than anaerobic exercise.
A daily program of sustained running is essential to achieving correct respiratory and circulatory development. The longer the periods of running, the better the results of the sustained effort will be.
You should understand that it is the speed of the running that stops you, not the distance. Running that breaks the even passage of time and distance is anaerobic, not aerobic, and it must be avoided.
All this running must be steady and even, at a pace that leaves you tired at the end, but knowing you could have run faster if you had chosen to do so. In other words, you should be pleasantly tired.
Your aim is to find your best aerobic speed over the various courses. If, during any of these runs, you find you have to ease back a · little to recover, you will know that you have moved into the anaerobic phase. This is neither economical nor desirable.
Continual creation of large oxygen debts by doing anaerobic training accumulates:
1) lactic acid and other wastes
2) upsets the nutritive system
3) reduces the benefits of vitamins
4) reduces nourishment from food
5) disrupts enzyme functions
6) slows recovery
7) makes further training difficult
8) upsets the nervous system
9) makes you disinterested and irritable
10) induces insomnia and low spirits
11) endangers your general health
12) makes you vulnerable to injuries and illness.
My most frequent admonition to athletes and coaches is: train, do not strain.
Running is without question the best exercise for runners and, provided you watch the degree of effort, you cannot really do too · much running.
Once you are moving freely over the shorter runs, you should move into one or two longer runs each week to maintain the improvement and build confidence in yourself. Do every other week for senior runners running 3 to 4 times weekly.
The anaerobic stage of your preparation should only be tackled after you have developed your aerobic capacity and maximum steady state to the highest possible levels. Four weeks of hard anaerobic training is usually enough. Do 8 weeks for senior runners running 3 to 4 times weekly.
Do not let age deter anyone from tackling long mileages, as long as the individual is happy about it and exercises carefully.
Running, I repeat, is the best exercise for runners, and the more you do in a balanced aerobic-anaerobic ratio according to this overall system, the better you will be.