A must-read for anyone who dreads stepping onto the treadmill
Q: Do I have to run to lose weight?
A: First and foremost, if you want to lose weight, you have to expend more calories than you take in. That means your number-one priority should be getting a handle on your diet. It should also be noted that weight loss doesn’t necessarily mean that you’re going to achieve the body you've always wanted. A much better approach is to focus on losing body fat while building lean muscle mass (or at least maintaining the lean muscle that you have). So, can running help you lose weight? Yes, absolutely. Is it necessary? No, it is not.
Contrary to what many people believe, resistance training (not running) is by far the most effective way to sculpt your body. It's the best way to build fat-burning muscle mass, and if performed in a circuit-like style (resting for only 20-60 seconds between each exercise), it can raise your heart rate and burn a lot of calories during the actual training session, in addition to elevating your metabolism for up to 24 hours after your workout.
Running does burn calories and therefore can help improve body composition, but not all running is created equal. The body quickly adapts to steady-state cardio like jogging. As a result, over time you will burn fewer and fewer calories for the same amount of effort. On the other hand, interval training (where you perform periods of high-intensity work followed by recovery periods of low-intensity work) keeps the body from adapting so easily. To get the greatest return on your investment of training time, make resistance training top priority, followed by interval training. There are certainly other health benefits of running, so if you enjoy it, go ahead and do one steady-state cardio session per week. But no, it is not required for fat loss.