Museum Walk

If you're looking to combine a walk with some art gazing, the walking distance between The Metropolitan Museum of Art and The Museum of Modern Art is a respectable distance but not that far.

Directions: The Metropolitan Museum of Art (1000 Fifth Avenue at 82nd Street) to The Museum of Modern Art (11 W. 53rd)
Distance, via 5th Av: 1.5733 miles
Calorie burn (approx.) at 142 pounds: 168.967 (rounded up, not that anyone weighs 142 pounds around here. OK, OKAY. Or that the same person weighed a ton (161) on May 30, but lost it over the course of the summer because he/she started walking around New York City every day, controlled calories and maintained a New York-themed illustrated diet and exercise journal with a running commentary on NYC culture that is now online.)
Walking Difficulty: Easy. Terrain is flat.

If you don't want to OD on art, I'd recommend just the new Greek and Roman galleries at the Met and the Richard Serra show at MoMa.

Every teddy bear, that's been good
Is sure of a treat today
There's lots of wonderful things to eat
And wonderful games to play