The great thing about running for exercise is that your body will start burning fat after only about a half hour of exercise. That’s because the body’s other source of long-term energy -- glycogen, stored in liver cells and muscles – gets used up in about a half hour, and this forces the body to start burning fat for energy. Lifting weights before running will increase the amount of fat you burn during your run, but running for a half hour a day four days a week will not burn as much fat as running for an hour twice a week.
Run for more than a half hour at a pace where you can still carry on a conversation. According to the University of Michigan Medical School, if you run at a pace where you are breathing hard but not getting completely out of breath, you will burn through the glycogen stored in your muscles in 30 minutes and then switch to burning fat.
Maintain a moderate intensity for 45 to 60 minutes for maximum fat-burning benefits. According to the University of Michigan Medical School, the running you do after 40 minutes into your workout will be the most beneficial to your health and appearance. Exercising for 30 minutes or less will burn calories and perhaps prevent you from adding more fat to your muscles, but it won’t burn fat.
Add interval training. Short bouts of fast running followed by slow recovery jogs will improve your endurance so you can exercise longer and burn more fat. One study published in "Metabolism" in 1994 found that people who did interval workouts over a 15-week period lost three times as much fat as a similar group doing a more traditional training regimen. Researchers at the University of New Mexico recommend that interval training make up no more than 10 percent of your weekly exercise total and that you do the sprints at a level you perceive to be hard or very hard but not all out. Your intervals can be from 30 to 90 seconds long, and you can increase their length or number steadily over time.
Try tempo running. Tempo runs are also done at a hard or very hard exertion level, but they are sustained for a longer period of time and not broken into intervals. Tempo runs should never be more than 10 percent of your weekly volume of exercise, so if you exercise for 200 minutes a week, your tempo runs should not be more than 20 minutes. With both tempo and interval running, you can increase the amount you do by about 10 to 20 percent per week. New Mexico researchers say both tempo and interval training enhance weight loss.
Lift weights before running. If you lift weights for 30 minutes, you’ll use up your glycogen reserves and your body will quickly start burning fat if you run immediately after lifting. Running after lifting weights also helps the body get rid of the lactic acid that may have built up in your weight-lifting muscles.
Drink a caffeinated beverage before running. According to "The Physician and Sportsmedicine" science journal, 150 to 250 milligrams of caffeine – a 16-ounce Starbucks coffee has 330 milligrams – improves fat metabolism during exercise. It can also help you exercise for a longer period of time. According to the journal, many athletes get their caffeine from strong, black coffee while others take over-the-counter antidrowsiness pills with caffeine.
- Northwestern University Medill School: Running Takes the Lead in Burning Calories
- University of Michigan: Timing Is Everything: Why the Duration and Order of Your Exercise Matters
- The Physician and Sportsmedicine: Fat Burning During Exercise: Can Ergogenics Change the Balance?
- University of New Mexico: Lactate Theshold Training
- ExRx.net: Sprints Burn More Body Fat Than Cardio Training
- Mix in some other types of exercise with your running in order to avoid an injury. Experts at Northwestern University say cycling and brisk walking are also good fat-burning exercises. Although neither exercise burns calories at the same rate as running, walking at a pace of four miles per hour or cycling at 15 miles per hour will nevertheless help you burn fat.
- With running and weight training, slowly build up your exercise time as your body becomes stronger and more accustomed to the work. Mix brisk walking with your running, start with light weights and increase your effort in each over time.
- When lifting weights, train with a partner who can assist you if you have trouble and who can monitor your movements to ensure you are performing them correctly.
- If you have never had a regular exercise regimen, check with your doctor before beginning one.
Jim Sloan is a writer and editor in Reno, Nevada. He has been a journalist for more than 25 years and is the author of two books, "Staying Fit After Fifty," and "Nevada: True Tales from the Neon Wilderness."