If you're a beginner, "increase your mileage and endurance with a mix of running and walking," Lyuda said. Start with five minutes of running, followed by five minutes of walking, until you've hit your target for time or distance. As you gain endurance and strength, decrease the time you spend walking, until you're running the entire length of your workout. Once you've done that, you can throw in some interval training to ramp up your calorie burn.