Q: I frequently see women at my gym take two Spinning or step classes in a row. Is this a good idea for losing weight?
A: "No, it's a shortcut to burnout," says Keli Roberts, group fitness manager at Equinox Fitness Club in Pasadena, Calif., and a spokeswoman for the American Council on Exercise. Doubling up also may increase your risk of overuse injuries, Roberts says.
A better way to increase the length of your cardio workouts is to choose a different activity after your class, such as walking on the treadmill or using the elliptical trainer, Roberts suggests. Not only will you work different muscle groups, but you also can go at your own pace and control the length of your workout.
However, don't assume that you'll improve your fitness simply by working out longer. Often, Roberts says, people who take back-to-back classes work out at a lower intensity than those who give it their all during a single class. "If you go hard in a Spinning class," Roberts says, "one session is plenty."