The experts interviewed for this story tended to favor strength-training exercises that target multiple muscle groups.
The experts interviewed for this story tended to favor strength-training exercises that target multiple muscle groups. Squats, which work the quadriceps, hamstrings, and glutes, are an excellent example. "They give you the best bang for the buck because they use the most muscle groups at once," says  trainer David Petersen of Oldsmar, FL.