Cardiovascular activity is strength training for your heart and lungs, as well as the best way to burn fat. The amount of cardio you should be performing is entirely based on your fitness experience. Having lost 50lbs myself, I can say with certainty that you need cardio to lose weight. I’ve heard talk of losing weight by strength training alone or minimal cardio. This is not true. While weight lifting burns fat by speeding your metabolism on a long term basis, cardio is the fastest way to shed pounds and allow muscle to show through.
The best thing about being a beginner, is that as long as you are doing something, you will see results! If you have never exercised before you may find cardio training to be a challenge. For the first couple of weeks, stick to an intensity where you can still just manage to talk without losing your breath. Try to maintain this intensity for 10-20 minutes. It takes approximately 20 minutes for cardiovascular activity to begin improving the condition of your heart and to start burning fat. Oppose to glucose/carbohydrates stored from your last meal. Once you can get to 20 minutes with ease, aim for 30.
If you have at least one year of exercise experience and you would like to lose weight aim for 30-50 minutes of cardio. You should also be regularly changing your routines. This can include choosing different programs on machines, running or cycling different routes and trying new activities such as hiking or fun runs.
If you are cutting for a fitness competition or you are already very active but would like to lose a few pounds try performing cardio twice in a day at 30 minutes each. Ideally it’s best to do this in the morning and then again in the evening. Try to make both workouts different from each other. For example, one session of cycling intervals, one session of high intensity running on an incline.
Cardiovascular training boosts your metabolism for up to 24 hours after a workout. If you stick to a consistent schedule of 3-5 workouts a week, at the recommended times and intensity you will reach your weight loss goals. Keep in mind that healthy, lasting weight loss happens at .5-2lbs per week.