Sweating out a midlife crunch

I use the stern railing as leverage as I yank the pole back and reel in the slack to keep the line taut. As the fish nears the boat, crew members scoop him up in a net and throw him at my feet. It's a yellowfin tuna, weighing a good 40 pounds.

"Call me Ishmael," I say to my friend Jeff Katz.

Don't get me wrong. I'm no Hemingwayesque hunter displaying my machismo in a Central American outpost. At 43, coming off knee surgery last winter after a ligament popped like a wishbone at Stowe, I simply want to play out my version of "Middle-Aged Man and the Sea." This is an opportunity to give my rehabilitated body a weeklong endurance test. My father-in-law had a textbook midlife crisis: ditched his family, married his secretary, and drove off in a Mercedes convertible. I happen to love his daughter and our kids too much to do something like that. And I'm an adrenaline junkie. All I want to do is shake off the rust (and a heavy layer of suburban malaise) with a dose of adventure.

I enlist Jeff, who leads a far too sedentary life socked away in a Boston office building trying to reach his law firm's quota of billable hours. We will spend a week traversing that outdoor lover's playground called Costa Rica. This little country bordered by Nicaragua and Panama, and by the Pacific Ocean and the Caribbean Sea, includes terrain ranging from 4,800-foot peaks in the cool environs of a cloud forest to the sweltering humidity of a Pacific rain forest, ideal for people who want to sample a different sport each day.

"I finally feel my heart beating," says Jeff after splashing through a stream on his mountain bike. We're on a dirt road at the base of a perfectly cone-shaped volcano, not unlike Osorno in Chile and Mount Fuji in Japan. The night before, Jeff and I had enjoyed the best light show ever as we watched a river of red flow from the crater of Arenal, one of the most active volcanoes in the Western Hemisphere. Even as we woke in the morning, you could hear the hammering of the eruptions and see puffs of smoke from the smoldering lava.