7 trips worth getting in shape for

Flickr/Robin Zebrowski

Lacking motivation to stay in shape this summer? Maybe you just need an incentive, like, say, surveying Africa from 20,000 feet up or having the Great Wall all to yourself.

Valaer Murray lines up once-in-a-lifetime adventures that will have you hopping off the couch and straight into the gym.

Grand Canyon Descent in Arizona

From the rim, you see the top half, and from a raft on the Colorado, you see the bottom half. But the only way to truly appreciate the Grand Canyon’s grandeur is the rim-to-river hike, a descent of about 5,000 feet. Thought that hiking downhill was easier? The 7.3-mile South Kaibab Trail proves otherwise. But, you'll pass through a multi-colored rift etched by prehistoric river currents on a trail originally forged by Hopi Indians.

Every switchback presents a chance to catch wildlife and a different soaring panorama. South Kaibab offers the shortest route, taking anywhere from three to five hours, while the Bright Angel Trail is more gradual and less exposed but 10.3 miles. Rest for the night in a rustic stone cabin at the Phantom Ranch (reservations open 13 months ahead) before you hike out in the morning.

Climbing Mount Kilimanjaro

Mount Kilimanjaro has long been known as the "Everyman's Everest," since it's the only one of the world's Seven Summits that doesn't require technical climbing skills. Still, climbing the world's tallest free-standing mountain is not for the weak. Only 40-50% of people are able to complete the climb. The biggest danger involved during the nearly 20,000-foot ascent is altitude sickness.

And the biggest reward? Watching the sun rise above the clouds, snow falling from above and a glacier below. Along the way you pass through wildly different climates, from rainforests to lava formations to alpine fields of lichen and grass. And hey, while you're checking off that bucket list, why not tack on a few days of hiking amid elephants and giraffes in the Serengeti?

Kayaking the Na Pali Coast in Hawaii

The coastline of the Hawaiian islands offers a coffee table book's worth of eye candy, from black sand beaches sloping up to palm fringed ridges, to rugged cliffs rising from the sapphire sea. But it’s Kauai that tops our kayaking bucket list for its isolated, rugged Na Pali coast. Some of the most spectacular scenery of the Na Pali State Park, like the Miloli'i Valley, are only accessible by sea.

One-day guided kayak trips are available, but we'd suggest a multi-day adventure so you’re able to explore the sea caves and virgin reefs along the way. However, we'd suggest taking along a guide, who will rent you kayaks and help you load up with necessities for camping at the two permit-only camping sites. Paddling for 17 miles in rough waters plus landing in high surf requires an experienced kayaker, but your reward is mile-high waterfalls dropping from emerald cliffs, deserted white crescents of sand and misty valleys only a few get a chance to see.

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