Intensity - How Hard Should You Work During Exercise?

Exercise intensity is just one of the important components of your workout program, part of the F.I.T.T. Principle, a set of guidelines that shows you exactly how to set up a workout routine.

The Basics of Intensity

Intensity is probably the most important element of your workout because, when you workout at a sufficient intensity, your body grows stronger and you'll see changes in your weight, body fat percentage, endurance, and strength.

 

Intensity is also something you want to monitor on a regular basis to make sure you're getting an effective workout.  Unfortunately, it's also one of the harder elements to monitor.  We have lots of choices, but none of them are perfect, so it often takes a combination of them to really get a sense of how hard you're working.

How to Monitor Your Cardio Intensity

You have plenty of choices when it comes to tracking intensity. Below are some of my favorites.

Heart Rate

Using a percentage of your Maximum Heart Rate (MHR) is probably the most widely used methods of tracking intensity because it's simple and you can easy monitor your heart rate by using a heart rate monitor.

For this method you use a formula, like the Karvonen Formula, or an online Target Heart Rate Calculator to get your target heart rate zone - The heart rate zone you try to work within to get the most effective workout.

The drawbacks here are that the formulas used to calculate THR aren't even close to perfect and can be off by as much as 12 beats per minute.

  Still, it does give you a place to start.

Talk Test

This is a very easy test to figure out your intensity.  You just pay attention to how breathless you are.  If you can easily talk, you're working at a light intensity, which is fine for a warm up.  If you can talk, but it's a little harder, you're getting more into the moderate zone.

  If you can only speak in short sentences, that's right about where you want to be for your workouts.

If you're doing high intensity interval training, that may include some breathless or anaerobic intervals where talking is out of the question.

Perceived Exertion

Your perceived exertion, or your RPE, refers to how hard an exercise feels.   The standard scale that you will often see is the Borg Scale of Perceived Exertion, which ranges from 0-20.

For my workouts, I like to use a 1-10 scale, which is a little less confusing.

The idea is to check in and ask yourself how hard you're working.  If you're very comfortable, maybe you're at a Level 3 or 4.  If you feel like you're exercising, but are still just in your comfort zone, you may be at a Level 5.  If you're sweating and very breathless, you might be at a Level 8 or 9.

How Hard Should You Work?

That question is impossible to answer for each person, but what I recommend is that you work at a variety of intensities - Low, Moderate, and High, throughout the week so that you challenge are your energy systems without overdoing it or underdoing it.

Sample Cardio Exercise Program

_Source

_{Source: American Council on Exercise. ACE Personal Trainer Manual, 5th Edition. San Diego: American Council on Exercise, 2014.}