What's the difference between weights and cardio for fat loss?

When it comes to burning off fat, weights have an edge over cardio. There’s a common misperception that resistance training can’t work your cardiovascular system, but ask anyone who’s ever performed a 20-rep set of squats if his heart rate is elevated. It will be.

Technically speaking, anything that elevates your heart rate is “cardio.” Traditional steady-state cardio (think running a 5K, using the elliptical machine, or doing step aerobics) can be beneficial in terms of fat loss -- at least for a while. But your body adapts to any stress placed on it. Over time, the work required to, say, run a 5K will decrease as your fitness improves. Diminishing returns kicks in. What once took 20 minutes to burn X number of calories will take 30 minutes, and then 40 minutes and so on. With weights, on the other hand, you can stave off this effect by varying your exercises to keep your body guessing. You can change things up by adding resistance, decreasing rest time, increasing the number of reps you do or changing the order of your exercises. All of these things prevent your body from hitting a plateau, boosting your ability to burn fat.

Lifting weights also increases your lean muscle mass, which further increases metabolism at rest. That means you’ll be burning more calories throughout the day...