A sweat session at Equinox or a fresh-pressed juice post-workout might never had been a thing if it weren't for fitness legend Jack LaLanne. The "Godfather of Fitness", who would be 100 today, started one of the first fitness clubs in the United States and was the first to endorse juicers, making the machine a household name. The Jack LaLanne Show was the first exercise program on TV, and the birthplace of catchy one-liners such as "your waistline is your lifeline" and "10 seconds on the lips, a lifetime on the hips." In light of this athletic hero's birthday, we caught up with his wife, Elaine, at the screening of his documentary Anything Is Possible in New York this week. Here, what she had to say about being married to a fitness pioneer, and of course, her favorite juice.

Shape: Jack was a weight-lifting, low-sugar diet evangelist way before it was cool. Have you always had the same lifestyle?

Elaine LaLanne (EL): When I met him I was smoking cigarettes and blowing smoke in his face until I found out what he was all about. It changed my life. I just wouldn't have been in the shape and condition that I am today. I did 10 pushups-mens style-yesterday. I'll be 90 in a year and a half.

Shape:Jack did some crazy stunts-famously swimming handcuffed in 1955 from Alcatraz to Fisherman's Wharf. How did you stay calm?

EL: I'd always worry, but you don't say no to Jack. He would always say to me "When I play, I play for keeps." That was his way of saying, "I'm determined to do this."

Shape: What's your favorite juice that Jack introduced you to?

EL: I never tasted carrot juice my whole life until I met Jack. I mix it with everything now-apple juice, celery juice. Besides, it's good for my eyes!