Thanks, Jack.

I’m talking about Jack LaLanne, the fitness pioneer who died Sunday at age 96. I have a few years to go before I hit that milestone (well, five decades), but you have to hand it to the guy: he knew how to keep it healthy. And he was an “exercise guru” before anyone really knew what that term meant.

I remember watching Jack on TV as a kid, doing jumping jacks in sync with the chiseled marvel. Today, I struggle to touch my toes. But adventure travelers should look to Jack for inspiration, because nothing can be more ruinous on a vacation than not being prepared for the rigors of a particular destination.

I’m thinking back to a trip I took eight years ago to the Galapagos. I still feel badly for the older travelers among the 29 explorers on our boat — by the end of a strenuous seven-day sail among the islands, three were so worn out they refused to leave the vessel. While the rest of us were looking at blue-footed boobies, they sat on deck chairs staring out to sea. I remember the wildlife expert assigned to the ship bemoaning the fact that they’d blown a once-in-a-lifetime opportunity.

Fast-forward a few years to the Grand Canyon. For months, I’d been preparing for a rim-to-rim trek, working out five days a week, going for miles-long hikes around Washington D.C. and walking seven miles to work with a fully loaded backpack. It wasn’t enough. By the time I reached Phantom Ranch in the bowels of the canyon, my left knee was throbbing, my back aching. The 105-degree temperatures didn’t help. I can’t remember much about getting out of the canyon the next day, except that it was excruciating.

Two years later, I did it again, this time preparing twice as long and arriving with better hiking poles, knee braces and a more realistic attitude. Ok, I battled a stomach bug the night before, but I still made it down in good time — and pain-free.

Now I’m preparing to do it again. I just joined a gym, I’m hiking on the riverside trail that edges my backyard and I’ve taken those knee braces out of storage. All I have to do now is get reservations at Phantom Ranch, which is easier said than done, alas, but well worth the effort.

And Jack? Something tells me that at my age, Mr. LaLanne could have made the hike blindfolded and shoeless — and he sure could do a mean jumping jack.

– written by John Deiner