Fran and Grace are the most well-known CrossFit workouts. There are also more difficult and scaled-down alternatives to most of the workouts.

The number of miles you'll need to run to lose weight depends on your size and your goals. You must burn off 3,500 calories to lose 1 pound. Running a 12-minute mile burns approximately 100 calories -- slightly more for larger people and slightly fewer for smaller people.

Not only is hooping fun, but it can also help you burn calories, shed fat and tone your muscles for a slim waist.

Everyone's body responds differently to the workouts and nutrition plan included with P90X. The program is designed to increase your fitness; weight loss is not a guarantee.

Interval training is better than steady state cardio for health and fat loss because its more intense.

Kickboxing is more than a pure cardio event -- it lets you release pent-up tension or aggression, improves your balance and strengthens your core. Thanks to the different muscle groups activated by your jabs and kicks, you’re also toning body parts that don’t usually get a workout when you run, walk or cycle.

How many calories you burn during HIIT depends on many factors, including your age, size and intensity level.

Losing fat and building stamina requires a well-rounded workout program including cardio and strength training.

Bursitis of the hip can be extremely painful and limit your range of motion. Clear any cardio with your doctor first.

When it comes to weight-loss, nothing beats the time efficiency of HIIT. However, steady-state cardio offers unique benefits, so make sure to include both.

Because weight loss is all about creating a calorie deficit — eating fewer calories than you burn day in and day out — tennis can be an effective way to lose weight. Playing singles especially is a high calorie-burning activity, although a good, competitive match of doubles will also help keep you trim.

Exercise doesn't have to take up hours of your day. Shorter, more intense workouts can be just as beneficial as one longer exercise session.