When it's workout time at Core Fitness Chicago, out comes the sledgehammer. And the 80-pound bag of mulch. And the 2010 Jeep Grand Cherokee for pushing across a rooftop parking lot while someone steps lightly on the brake.
Don't even bother looking for a treadmill.
If such exercise sounds ambitiously modern, it's not; those tools are meant to imitate the way humans stayed healthy 10,000 years ago.
