This is the number of calories I burned in a boxing class on Monday night, according to my heart rate monitor.  For comparison’s sake:  a 45 minute spin class burns about 450, the kickboxing class I like burns about 550.  This is also the reason I am still so sore that it still hurts my arms to brush my hair and it hurts my legs every time I stand up.  I had never taken this boxing class before — I’ll definitely keep it in the rotation — but, man, did it kick my ass.