Before Darwin conceptualized the idea of "survival of the fittest," cheetahs with six-packs and rope-skipping elephants were already spending all their free time at the gym. Work your body like it really matters with today's Groupon: for $20, you get a five-visit pass for fitness classes (a $40 value) at Jack Purcell Recreation Association in Centretown.

JPRA pumps up locals with an arsenal of seasonal fitness classes offered throughout the week. Transforming bodies with a little bit of sweat and no black magic whatsoever, winter fitness classes available through the end of March include the Latin dancercise Zumba, the aerobic rollercoaster workout, a total body conditioning class, the ab-assaulting core cruncher, the toning total body blitz, and the low-impact cardio combo. Five-visit pass holders can choose to redeem all classes in a single fitness program, or mix and match. For every pass sold, Groupon and the Jack Purcell Recreation Association will donate $12 toward upgrading the Jack Purcell Park to include an accessible play structure for children of all ages and abilities, so you can whittle down your waist knowing it's for the greater good.