Cardio: Is 20 minutes enough?

Is 20 minutes enough?  First and foremost keep in mind that all cardiovascular activity is better than zero.  The next question we need to answer is what is our goal? In order to reap the benefits of cardio on our cardiovascular functioning, we need to overload our heart. Just as in resistance training, we need to overload a muscle if we want it to become stronger. You wouldn’t become stronger lifting 5-pound weights day in and day out. However, if you throw in a few heavy lifting days a week, you would see improvement in your strength.  The same holds true for our hearts.

Now let’s think about this again, what if you tried to lift your max seven days a week? Chances are you wouldn’t be able to and you might even get hurt. The same idea holds true for cardiovascular activity. You might be able to train at close to max intensity multiple days in a row, but chances are your body is not recovering and you are likely preventing yourself from reaching your potential.

Ideally, the goal should be to strike a balance between over-load and not over-doing it.  The American College of Sports Medicine recommends 20-30 minutes of high intensity workouts at 77-90% of heart rate max to improve overall health and fitness (1). This time does not account for the time spent warming up or cooling down.  The number of times per week at this intensity depends on your goals and fitness level.  Elite athletes may train at this level daily where the average person should aim to train this way three times a week in an effort to improve cardiovascular activity.  If one is trying to lose weight, additional cardiovascular sessions will likely be needed, but not all have to be at an intensity of 77-90% of your heart rate max.  (insert link for heart rate max).

Remember, all exercise counts. If you are pressed for time, a high intensity workout may be the perfect workout to reap the maximal benefits.  Ideally, try to get in at least 3 good, intense sweat sessions a week that will overload your heart! Of course, make sure it is okay with your physician before you engage in intense exercise!

Segment	Minute	Speed
Warm Up	0-5	6.0
	5-10	6.5
Intervals	10-11	3.0
	11-12	9.1
	12-13	3.0
	13-14	9.2
	14-15	3.0
	Repeat until minute 40	Increase run speed by 0.1 each run
Cool Down	40-45	3.0

Here is an example of a high intensity morning treadmill workout I do three times per week. You can always shorten the intervals as well as the time spent running!  Let me know how it goes!

References: 1. ACSM’s Resources for the Personal Trainer, 2^nd Edition Lippincott Williams & Williams 

Give it a shot and let me know how it goes! Tweet me @kelleyvargo #HighIntensity

See you tomorrow,

Kel