It's an age-old argument and one that's not easy to win. There are those who swear that building strength is best, and there are those who swear that getting the heart pumping is best.
The truth is that both are good, but which is best depends on your goals. Here's a look at the pros and cons of each:
Burning calories
On the surface, it may seem that cardio is the obvious winner when it comes to burning calories. But a closer look reveals that strength training actually results in bigger burns.
On average, you'll burn about 10 calories every minute you spend doing cardio, which is more than you'll burn lifting weights. However, once your strength-training workout is over, your body will continue to burn calories for an hour—up to 25 percent of what you burned while you were lifting.
Another advantage of strength training is that you'll be building muscle, and every three pounds of new muscle you build results in an extra 120 calories burned throughout the day. In the course of a year, that's 10 pounds' worth of calories you'll be burning—without even hoping on a treadmill!
The lean look
If you've ever seen an avid weight lifter admire him or her bulging biceps while flexing in the mirror, you know strength training isn't about getting a long, lean muscles—it's about getting big(ger) in all the right places.
Cardio, on the other hand, is all about looking lean. You stretch your muscles before you workout and then you get the blood flowing while burning calories. It's the perfect combination for getting lean.
Finding time
Finding time to get a high-quality workout in three times a week can be hard to do. Experts agree that a good cardio workout takes at least 20 minutes. Strength training? That can be more difficult. You need to work your core (abs and lower back), your legs, your shoulders and your arms. A good workout usually takes an hour.