EVERYONE IS GETTING INTO THE PACK

A year ago, when Co Rentmeester took these pictures at the Boston Marathon, 1,898 men and women were entered. This April 18, in the race's 81st running, there will be a field of 2,500. Marathoning, once a feat for hardy loners—15 men competed in the first Boston Marathon—has become a mania. Until 1965 Boston usually had between 250 and 400 starters. But by 1969 there were 1,152, and in 1970 the field had to be limited by a qualifying time (now three hours for men under 40, 3:30 for women and for men over 40). Fifteen years ago there were only six marathons in the U.S.; last year, 166. And the goal is no longer just to finish but also to clock a good time. In 1970, 812 men completed a U.S. marathon in under three hours; last year 3,600 men and women did so. Now it seems inevitable that another record year is upon us as more and more marathoners get set to test themselves over that magic distance: 26 miles, 385 yards.

Last year runners hosed down to beat the heat. Other years they have bundled up against sleet.

A phalanx as it streams through Hopkinton, the field will quickly become a miles-long parade.

Their contribution can only be a brief cheer, but still the proud, hopeful families line the streets.

Unabashed support for a runner often is enough to spur him on—if only one more torturous mile.

Some call it the "meat wagon." It patrols the course, picking up those the distance has defeated.

There are race-watching regulars, too, and they are equipped for their own test of endurance.

The final miles often become unendurable and sometimes the body simply has to surrender.

To reach Prudential Center is the common goal. To do so yields satisfaction that is uncommon.

For many, exhaustion will be mixed with joy. For others, it is so total there can be no feeling.

THIRTEEN PHOTOS