The simplest way to stay fit is to just go for a run right? It doesn't cost anything, you can do it almost anywhere and it's a good workout. The U.S. Track and Field Organization estimates there are 50 million adult runners in the United States alone.
But for the aging runner who's laced up the sneakers all their lives, now the hip pain or knee pain is telling them running is no longer an option.
Many have tried biking, but to get a similar workout to a run, you have to bike for two to three times as long. And being hunched over or looking down for a few hours can be a pain ... and that doesn't even take into consideration the pain in the posterior that bikes can evoke.
The solution for many has been trips to the gym for the elliptical machine: a gliding no-impact exercise machine that prolongs running, but it's indoors and stationary, AKA boring.
Enter the Elliptigo. It's a cross between a road bike and an elliptical machine at the gym. Zero impact, you get a runner's workout in 30 to 45 minutes while riding the Elliptigo outside on the road.
I tried it in Northern California after my friend Missy Park introduced me to the new device.
A former basketball player, Park used to run every day but that stopped a few years ago. Last Christmas when she and her family were writing their annual letters to Santa, Park asked for new knees.
"Instead, Santa bought me the Elliptigo," she said.
Her partner Dana Tillson thought the device would be perfect for the time-crunched Park.
As I first get on the Elliptigo, I immediately notice how tall I feel -- you ride much higher than on a standard bike. Balancing the nearly six-foot-long device was surprisingly easy and with a few strides I'm on my way.
I steer warily at first and while the Elliptigo doesn't have the turning radius of a standard bike, it's plenty maneuverable. I shift gears; it works just like a bike and I'm ready to go.
Riding with Park, who's a pro now that she's had the device a few months, proves a little harder. I'm huffing and puffing right out of the gates and this old friend is quickly trash-talking me.
But the workout is both effortless on the joints while being a substantial fitness challenge.
"For me, there's something about being up on my feet," Park said. "It feels more active ... and then the other thing about riding a bike -- you're in for about two-and-a-half hours whereas this, you can get a good workout in 45 minutes to an hour."
One thing we both notice as we ride, everyone is staring at us.
"You have to have significant energy just to talk to everyone who wants to know about the Elliptigo," Park said.
The device has plenty of fans, from ultra-marathoner Dean Karnazes to teams like the Boston Celtics, who use the device as a cross-trainer. There was even a "World Championship" Elliptigo event last year: 30-plus competitors tackled the steep 3,990-foot, 11.68-mile Palomar Mountain ascent in California.
So far the device is only for road-biking, not mountain biking or off-roading. And the other significant issue is the price: it starts at $1,800.
But Bryce Whiting, an Elliptigo spokesman, said "that's about what you'd pay for a quality road bike." And as with all new products one can only hope the price will come down as more are manufactured.