By Sara C. Medina

A vigorous older man leads a party of hikers along a mountain trail, pauses beside a waterfall, naps under a tree after a sandwich-and-soft-d rink lunch. A typical day in the country--except when the hale sexagenarian happens to be Pope John Paul II, taking a rare and precious break from papal responsibilities. His doctor is known to have repeatedly urged him to get more exercise, and he has long had an enthusiasm for outdoor activity. The outing, with his secretary, Stanislaw Dziwisz, some friends and ever present bodyguards, apparently took place last year during his summer vacation in an isolated area of the central Apennines in the Abruzzi region, 75 miles east of Rome. No one is saying just who in the group took a few pictures, but they first appeared in the West German and Italian weeklies Bunte and Gente this month. According to the reports, John Paul met no one, indulged his nostalgia for the mountains of his native Poland and returned refreshed.