To describe the agony of a marathon to someone who's never run it is like trying to explain color to someone who was born blind. ---Jerome Drayton
Jerome Drayton was one of the top marathoners in the world back in the 1970s, winning the prestigious Fukuoka Marathon 3 times (including a 2hr 10:08 in 1975), and Boston once, in 1977. A colorful character in the world of marathoning, Drayton actually competed in the 1968 Mexico City Olympic Marathon as Peter Buniak, the name he was born with. He changed his name to Jerome Drayton in 1969. According to Blaikie, Drayton's complaining following his Boston victory was instrumental in bringing long overdue changes to this historic event. Unbelievably, the year Drayton won there were no official water/refreshment stops. Runners relied on crowd support for water and whatever other fluids they could get.
He (Drayton)trains in disciplined phases, six in all, that can last up to eight weeks each. The first consists solely of long, slow runs to build up his aerobic base. Occasionally he will travel more than thirty miles in an outing. Hill work follows. Three times a week he will pick out a hill on his training route and assault it repeatedly to toughen the workload. In the third phase he varies the routine not with hills but timed quarter-mile intervals on the track. Twelve, fourteen, sixteen times he will circle the track at a pace that takes him to the edge of his anaerobic threshold, the point at which his body begins to slip into oxygen debt from the stress. This usually occurs with laps of about 65 seconds, a 4:20-mile pace. Between each interval he walks to recover.
In the fourth phase he deliberately pushes his body into oxygen debt, running quarters at maximum effort with almost no rest in between. So stressful is this form of training that it can exhaust an athlete of Drayton's stature in fewer than half a dozen laps. At least two, often three, track workouts a week are included in his schedule. Then follows the fifth and most taxing phase in which Drayton combines both aerobic and anaerobic intervals in the same session. Quarters that previously took sixty-five seconds to cover without going into oxygen debt he now flies through in just fifty-seven seconds, the pace of a world-class miler. Through all these phases his total training rarely drops below one hundred and thirty miles a week.
The sixth and final phase comes when Drayton "rests" by tapering back to about seventy-five miles a week and substituting short weekly races for the speedwork of the track. Competition sharpens him mentally and prepares him for the ultimate challenge toward which all phases of the cycle have been directed, usually a major marathon. It is in this phase that he reaps the reward of his discipline, that all the effort and sacrifice pay off. That sweet feeling of rejuvenation sweeps through his body and all the stressed comers of his being come together in climactic unison. The sensation is one of vitality and strength that few human beings know.
source: davidblaikie.com (this is a great read!)