How Hard Do I Work When Exercising? Borg RPE Scale, The Talk Test, and Target Heart Rate Range

Often, clients will ask me “How hard am I supposed to work when performing cardio?” Essentially this is referring to intensity of the workout. The harder you work the more calories you are going to burn and the quicker you will lose weight and reach your goals. There are a three main ways to determine how hard to work including the Borg RPE scale, the talk test, and taking your target heart rate range.

1. Follow the Borg RPE scale. This is a scale that runs from 0-10 based on how hard or easy you are working out. Zero equates to sitting in a chair, while ten is something that is very difficult and can only be sustained for a brief period of time such a few minutes. Generally you should fall somewhere between a 4 and a 6 to get maximum benefit out of your workout.

0 – Nothing at all

0.5 – Just noticeable

1 – Very light

2 – Light

3 – Moderate

4 – Somewhat heavy

5 – Heavy


7 – Very heavy



10 – Very, very heavy

2. Try the talk test. You want to get to a point where talking is a bit difficult while you are exercising, yet it can still be done. If talking is a breeze, then pick up the pace or if you’re wheezing and couldn’t talk if you tried, then you need to slow down the pace until you can.

3. Determine your target heart rate range. Whether you count it yourself or use a monitor, your pulse can be a great measure of intensity. You want to keep you target heart rate range between 65-85% of your maximum heart rate.

To determine your maximum heart rate use this formula:

220 – Your Age

Once you have that number multiply it by .65 and by .85 to get your target heart rate range. This number gives you the beats per minute you should expect to reach a fat, burning intensity. Keep in mind this is an estimate and some medications can affect your pulse.

By using the Borg RPE scale, the talk test, and your target heart rate range you should be able to determine how hard to work when exercising so that your workouts are effective and burning off those calories so you can lose weight and be healthier.