You Can Lose Over 20 Pounds in 3 Months — Here's How

"For weight loss, cardio is king," Jim said, adding that the American College of Sports Medicine (ACSM) recommends 300 minutes of cardio training a week for weight loss. "I would recommend low to moderate continuous exercise," he said.

If 300 minutes sounds like a lot, it doesn't have to equal vigorous HIIT training or an intense Spin class. Your cardio workout should be at least continuous cardio at a moderate level, reaching 60 to 70 percent of your max heart rate.

Running not your thing? Go for a brisk walk, swim laps, ride your bike around the neighborhood, or jump rope — anything that will get your heart rate up and make you break a sweat.