Cardiovascular exercise, Cardio for short as we all know, comprises of some sort of activity (mostly running / jogging / walking, rowing, stair climbing) that elevates the heart rate over an extended period of time.
Cardiovascular exercise has a lot of health benefits like lowering your blood pressure, strengthening your heart and it can also burn a lot of calories – for those who want to lose weight.
However, in order to effectively change your body composition, one cannot solely rely on cardio. Cardio exercises will help you expend calories only within the time frame in which the activity is performed. In addition, cardio exercises do not induce the human body to build any muscle. In other words, if you start off as a flabby individual and rely solely on cardiovascular exercises, you end up becoming a 'smaller' flabby version; big pear to small pear!
So what should you do?
You would need to incorporate a muscle building regimen (resistance / weight training) such that you will be expending calories even after you have finished your workout. Remember, your body burns calories while it repairs and builds muscle. Every time you partake in any form of resistance training, the recruited muscle groups in the activity incur micro 'tears'. The repair and healing window of these muscle micro tears is about 24-48 hours. During this muscle building window, calories are burnt and your body fat is targeted
Therefore, the goal should be to continuously place your body in this fat burning / muscle building window; whereas, when you workout, you should focus on burning as many calories as possible while performing exercises inducing maximum muscle formation.
Cardiovascular activities should an integral part of your exercise regimen and not your entire exercise regimen!
Partake in a weight / resistance training routine 3-4 times a week. Perform cardiovascular exercises 2-3 times a week.
What sort of cardio should you do?
When it comes to cardiovascular activity, there are two trains of thought – Low intensity, Long Duration (LILD) and High Intensity, Short duration (HISD).
Low intensity, long duration cardio is performed at a low intensity (65% of your maximum Heart Rate) over a long duration (45-60 minutes).
The advantage of this approach of cardio training is that a majority of calories expended are from fat stores. Remember, when calories are burnt during any sort of cardiovascular activity, it robs calories from your fat and muscle stores collectively. It is virtually impossible to lose body fat without losing any muscle mass. This approach minimizes the depletion of muscle mass. In addition, it places a lot less repetitive stress on your joints that may come along with such activity
High Intensity, Short duration cardio is performed at a very high intensity (80-90% of your maximum Hear Rate) over a short duration (generally 25 minutes or less). This approach burns a lot of calories and revs up your metabolism. In addition, HISD also improves ons agility and overall explosiveness.
Ideally, you would want to alternate between the two approaches for a period of six weeks and monitor your progress through a journal and weekly photos of yourself. Focus on losing as much body fat without depleting too much muscle mass.