Everyone knows that cardio exercise is a key factor in losing weight, but the best cardio workout is the one you will want to do regularly and consistently. If your primary goal is to lose weight, then focus on burning as many calories as possible in your workout. For example, if you plan to lose 1 pound a week, that's a total of 3500 calories. Then you should burn at least 500 calories a day doing cardio exercise 5 days a week.

Now finding cardio exercise that burns that many calories and keeps your interest at peak each and every day is not easy. So, the first thing you need to do is to find a workout that you not only feel comfortable doing but that you really enjoy.

*Below is a list of some cardio exercise that burns the most calories in 30 minutes:

1. Spinning (indoor cycling) - 450 calories
2. Swimming - 380 calories
3. Step Aerobics - 345 calories
4. Kickboxing - 345 calories
5. Racquetball - 345 calories
6. Rock Climbing - 380 calories
7. Cross-country Skiing - 310 calories
8. Running - 310 calories
9. Elliptical Trainer - 265 calories
10. Walking - 130 calories

(*Actual amount of calories burned varies by weight, age, and intensity.)

Remember consistency is a key to losing weight. Sticking with a cardio workout program combined with healthy nutrition are essential. You should also always consult a physician before tackling an exercise regimen. Be cautious and start slowly at first, then gradually intensify your workout. Don't cheat, really push yourself. You'd be surprised how much your body quickly adjusts to the routine and how fast you build endurance.