The creator of the P90X workout is touting his program in his first book.
Horton doesn’t pretend his workout plans are easy, but he does promise not to overwhelm anyone -- even beginnners.
"They want to eat healthy food, and they don't want to do an hourlong workout,” he said of people new to intense workouts. “They want to do 20-minute workouts."
And the man who started as a trainer to celebrities, now has lots of fans himself.
“We're pulling people out of gyms, and they're saving a whole lot of time,” he said. “They’re saving a whole lot of money.”
And many of his fans like how they can work out at home on their own time and at their own pace.
"In the convenience of your own house, you don't feel embarrassed if you're 50,60, 70 pounds overweight," he said. “You can go at your own speed and pace. You can hit the pause button if you want, if there's some part of the DVD you're struggling with.”
Among his supporters: celebrities Pink and Sheryl Crow.
"Charles Barkley just started,” Horton said. “I mean, it's just kind of crazy. When you have that kind of unsolicited support, people are going to start talking about it."
More: Tony Horton's World