Your six-pack shape is largely genetic. Here’s what determines how your abs look – and what training can (and can’t) change.

That's how Jay Cardiello, the celebrity trainer behind 50 Cent and Kevin Love, designs his workout routines. That's how Jay Cardiello, the celebrity trainer behind 50 Cent and Kevin Love, designs his ...

Heimlich is a contributor for TIME. Heimlich is a contributor for TIME. A hard workout can come back to haunt you. When you wake up the next morning and try to get out of bed, everyday motions like ...