Between taking daughter Suri Cruise to an NCAA game at MSG and on a shopping trip at Bergdorf Goodman, Katie Holmes took some time for herself in the Big Apple recently, sweating it out at Barry's Bootcamp in Chelsea.

We're told the actress played it low-key during the 4:20 p.m. class, going "about her business" and working "hard" in the class, a witness told us.

"No one made a big fuss," the witness said.

The 35-year-old wore a fitted pair of black pants and a black tank.