Greg Glassman, founder and CEO of CrossFit, believes his exercise program works for everyone.
CrossFit workouts are the same for every person who walks into a gym. The only differences are the amount of weight used and the intensity.
"Our understanding is that the needs of Olympic athletes and our grandparents differ by degree, not kind," Glassman told CNBC. "One needs functional competence to stay out of the nursing home. The other one wants functional dominance to win medals."