Cardio workouts

Cardio exercise is a sustained exercise that forces your heart to beat relatively quickly for an extended period of time.  This is the most recognized form of exercise because it is easy to do, no assembly required.  A cardio exercise must last at least twelve minutes to provide any significant benefit to your heart, but unless you are going really hard, this is not enough either.  Most cardio workouts last anywhere from 20-60 minutes.  The idea is that you force your heart to work really hard for a while which causes your heart to build strength over time and become more efficient so that it actually beats more slowly during daily activities than it used to, and yet delivers the same amount of blood to your cells.  It also has other benefits such as expanding blood vessels, which further decreases the workload on your heart and your chances of heart disease.  Your heart can only last for so many beats before it just runs out of life.  So, although cardio exercise causes your heart to beat much faster than normal, it is only for a relatively short period of time.  During the non-exercise portion of the day your heart will beat far fewer times than if you didn’t exercise at all.

Let’s say your heart rate is about 80 bpm (beats per minute) during the day.  You start exercising and after a few months your average heart rate is down to about 75 bpm.  Although it may not seem like a huge difference, 80 bpm is the same as 42,048,000 beats per year whereas 75 bpm is 39,420,000 per year.  Remember your heart never stops beating, but by only lowering your heart rate 5 bpm, you save your heart 2.6 million beats each year.  Trying forming a fist 2.6 million times in a row and then decide if this is a significant difference.  Let me give you another scenario to really drive this idea home.  My resting heart rate (when I’m awake) is about 60 bpm.  My non-exercising friend’s is about 90 bpm.  In one year, his heart beats almost 16 million times more than mine.  Convinced yet?

The point here is clear; The more times your heart beats, the closer it is to stopping, no matter how healthy you are!  However, you can get many more beats out of a healthy heart than a docile one.  Good cardio exercise will allow your heart to beat tens of millions of fewer times in your life; thus, it will last you longer.  And as you strengthen your heart, you will also increase the number of times your heart is able to beat before it poops out.

How to do good cardio workouts

To make it simple, a cardio workout is nothing more than a continuous activity lasting a minimum of 12 minutes that keeps your heart rate at a particular target level.  The “level” at which your heart beats for those 12 (hopefully more) minutes is very significant in regards to how much benefit you receive from a cardio exercise.  The longer you exercise, or the faster your heart beats, the more benefit you will get, to a degree of course.  Having said that, I do not mean to say if you run for 2 hours you will get precisely 4 times the benefit of running for 30 minutes.  In fact, quite the contrary.  The longer you do cardio, the more benefits you will reap for your heart, but after a certain point the rate at which you gain those benefits decreases.  The following chart gives a general idea of benefits received over time for a cardio workout.  Notice that the payback is always increasing, but over after long enough, the benefits are hardly even worth the time.  That’s why ultra runners, although healthy, don’t live significantly longer than other healthy people.  Sure they spend hours a day running, but the most benefit comes in the first hour.  After that, more running can sort of erase some of the benefits.

This graph is in no way meant to be precise as to what points exercise benefits increase or decrease. It is simply to give you an idea about how exercise benefits vary over time.

Now don’t be concerned about running a marathon or anything like that, its a great thing to do if you have the time to train, but realize that getting good cardio workouts doesn’t require hours pounding the pavement.  At the same time, strictly from an overall health perspective, the most benefit to be gained from a cardio workout is anywhere from 15-40 minutes, depending on intensity.  Obviously you can’t “go all out” for 40 minutes, but if you are going for 15, your intensity must necessarily be higher if you are to get similar benefits to going for say 30 minutes.