Gardening can be a terrific workout, so take your clippers beyond the hedges of your own property. Keep in mind that while potential volunteers are often inspired when they notice the tulips blooming in spring, most forget to come back in the fall when extra hands are needed to plant, rake and help with ground prep. Outdoor lovers can also volunteer year-round to clean up and weed local parks or historical sites like cemeteries. Start by contacting your city's parks department, horticultural society or historical preservation organization.
Calories burned: 572 for two hours of general gardening; 716 for the same amount of time of strenuous work like digging, spading, spreading mulch or composting.
Muscles worked: Legs, arms, shoulders and abs (lifting bags of mulch and pushing wheelbarrows are similar to weight training); back and core (reaching to prune tall branches).
Karmic bonus: A greener environment.