Wow! I can't think of a guy that better exemplifies what can be done by someone over 35:
"In 1954, when Jack was half his current age--not long after he won that year's Professional Mr. America contest and something called the Best Chest award--he began to attempt a series of midlife feats of Herculean strength and uncanny endurance that were designed to call attention to his cause. He did 100 handstand push-ups in under six minutes. He swam through the powerful currents between Alcatraz Island and Fisherman's Wharf in San Francisco while handcuffed. He towed a 2,000-pound boat the length of the Golden Gate Bridge while swimming underwater with air tanks but no fins, and he somehow did 1,033 push-ups in 23 minutes during an appearance on TV.
In his sixties, Jack began to wear shackles on his legs as well as handcuffs for the swimming feats. He used the "flopping butterfly" stroke he developed to tow 13 boats symbolizing the original colonies across a southern California bay as a 1976 bicentennial feat, and he towed 6,500 pounds of wood pulp across a lake in Japan the year he qualified for Social Security. At the age of 70, he towed 70 friends sitting in 70 different boats across Long Beach Harbor near Los Angeles, despite heavy winds."
Here's the link if anyone is interested: