"Hearst Magazines and Yahoo may earn commission or revenue on some items through the links below." If you've completed a core workout—or 100 of them—over the years, you likely know what crunches are ...

While many workout regimens flame out as quickly as it took them to start trending, others stand the test of time. Exercises like tai chi, running, swimming, hiking and yoga, for instance, have been ...

I'm not a huge fan of crunches. The move is easy to perform incorrectly and doing so puts a lot of strain on the neck. Another reason I don't love them is that if you're short on time, they aren't the ...