A reader asked me this on the prevention.com discussion boards. To get started, you’ll need a way to sculpt muscles, and a form of cardio to burn calories and keep your heart healthy. Convenience practically guarantees results: Home exercisers in one study lost 66% more weight than gym goers.

For Strength Training:

Dumbbells. At less than $25 a pair, you’ll want one lighter set (3 to 5 pounds) and one heavier (8 to 10 pounds). If you’re short on space or travel often, resistance bands are a great alternative. I recommend a set like the Pumping Rubber Workout kit ($35; spri.com).   Bonus Buy: Use a stability ball to target your middle during strength moves like chest presses, or to make crunches more effective ($12; amazon.com).

For Cardio:

Videos. I think fitness videos are the number-one value in home aerobics. For approximately $15 each, workout DVDs bring high energy cardio dance, kickboxing, or walking workouts (no treadmill required!) to your living room. You need only one to start—often, you can mix-and-match different routines on the same disc. Check out collagevideo.com for a searchable database of DVDs with detailed reviews and online previews of workouts.   Bonus Buy: To crank up your calorie burn even more, add an exercise step ($66; spri.com). Moving up and down either to a step DVD or even while watching TV burns up to 580 calories an hour while toning your legs and butt.   Get fit after 40! Ready to invest in a cardio machine? Visit prevention.com/cardiomachines for our favorite joint-friendly picks.   Chris Freytag is a board member of the American Council on Exercise, the star of many Prevention Fitness Systems DVDs, and author of Prevention’s Shortcuts to Big Weight Loss (chrisfreytag.com).