And some are a little of both.
This is Bernice Bates, a 91-year-old yoga teacher from St. Petersburg, Florida.
Bates recently entered Guinness World Records as the oldest yoga teacher in the world -- and she says the record isn't all that important to her.
"Anyone that can beat the record is fine," Bates told HuffPost Weird News. "I'm sure there's a 100-year-old guy in India who can probably beat me."
Bates, who took up yoga more than 50 years ago, affectionately refers to her students as her kids -- which is funny when you consider that most of them are seniors themselves.
She marked her achievement as the oldest of her kind on the seventh annual Guinness World Records Day, which was held on Nov. 17.
"It's a chance for everyone around the world to try a record, try to break one or set a new one," Guinness editor-in-chief Craig Glenday told HuffPost, adding that he was most interested to see if the record for largest gathering of people dressed as leprechauns would be broken.
Did it happen?
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