What's YOUR excuse? 100-year-old woman never misses a workout!

MILWAUKEE (WITI) -- She's 100 years old, and she could be living proof of the benefits of regular exercise.

Elizabeth "Nan" Smith is the oldest member at her New York sports club. She celebrated her 100th birthday on Sunday, April 27th.

And she says she never misses a workout!

Smith regularly takes part in a national fitness program for seniors called "Silver Sneakers."

Smith says exercising has helped her to lose weight, and also to feel younger.

"I was a nice size 12. Then I went up to 16W. Now I'm back to 14. I improved my agility to walk faster. Do more spontaneous things. After my fall it set me back, but now, here I am. I don't feel a hundred. Some days I do. But it's nice to be among friends, which eliminates a lot of my distressful thoughts. I guess God wanted me this far," Smith said.

Smith's instructor says Smith puts in a lot of effort.

"At times, she is feeling very strong and very vigorous and she's right there with us. Other times she tells me 'I feel a little tired today.' We modify the exercises and she does her absolute best," Instructor Susanne Hiller said.

Smith's friend, Renata Morelli drives Smith to the gym.

"I'm her driver. I've been driving her for the last two-and-a-half years now. In the morning I call before I go. I say 'Nan, how are we doing today?' And she says 'Are we going?' She gets all excited. If I want to back off I can't because she has to come here," Morelli said.

Hiller says Smith's determination encourages a lot of the other seniors in the class too!