Workout By the Numbers


If you want to take charge of your fitness, there are two scales that will help you sort through the noise: Metabolic Equivalent (MET) and Rating of Perceived Exertion (RPE). As a personal trainer, I use these charts when training with clients and communicating with other allied health professionals. They’re a convenient way to structure every workout.


The MET is a practical procedure for expressing the energy cost of physical activities. 1 MET = the energy (oxygen) used by the body at rest. The harder your body works, the more oxygen is consumed and the higher the MET level. Activity that burns 3 to 6 METs is considered moderate-intensity physical activity. Activity that burns more than 6 METs is considered vigorous-intensity physical activity. Moderate-intensity physical activity causes an increase in breathing and/or heart rate, results in 3-6 METs of effort, and burns 3.5 to 7 Calories per minute (kcal/min). For example, kissing and hugging uses about 1.3 METs, mowing the lawn with a power mower uses about 5 METs, and “Dance Dance Revolution” uses about 7.2 METs. Compendium of Physical Activities


The RPE scale is used to measure the intensity of your exercise from 0 – 10. The numbers relate to phrases used to rate how easy or difficult you find an activity. For example, 0 (nothing at all) would be how you feel when sitting in a chair. 10 (very, very heavy) is how you feel at the end of an all-out effort. Include increased heart rate, increased respiration or breathing rate, increased sweating, and muscle fatigue. Don’t concern yourself with any one thing like shortness of breath, but try to focus on your total feeling of exertion. Think of your exertion without thinking about what the actual physical load is or how it compares to others. Although this is a subjective measure, once you get familiar with using it, it will provide a good estimate of your actual heart rate during physical activity.

RPE 10 Scale

0 – Nothing at all (I do this all day.)
1 – Very light (I could probably do this all day, too.)
2 – Light (This isn’t so bad.)
3 – Moderate (I can feel this.)
4 – Somewhat heavy (I can really feel this.)
5 – Heavy (Wow, you want me to do this for how long?)
6 – Heavy (You’re crazy if you think I’m doing this very long.)
7 – Very heavy (If I could talk, I’d have some choice words for you.)
8 – Very heavy (Really, can I stop?)
9 – Very heavy (I have to stop!)
10 – Very, very heavy (I’m dead.)

What Level of Exercise (MET)?

New: If you’re new to exercise or just getting back in shape after being inactive, you can start with just 15 minutes of exercise per day. Go for light to moderate exercise (3-6 METs). Add a few minutes to your exercise time per week until you’re completing 25 minutes.

On-and-Off: If you’ve maintained some level of conditioning, you should exercise at a more vigorous level for at least 25 minutes (6-8 METs). Add a few minutes of exercise time each week. If you choose a light effort activity on a given day, just add 15 minutes to your total exercise time.

Steady for 6 months: If you’ve been exercising consistently, progress to 45 minutes of vigorous exercise for 6 days per week (6-8 METs). Try short bursts of hard effort (interval training like Tabata, HIIT or HICT) during 2 workouts per week, but not on consecutive days (9-10 METs).

What Level of Effort (RPE)?

Choosing the right level of effort allows you to make progress without hurting your muscles and joints. How can you know if a workout is too easy or too hard? Use the RPE Scale.

New: Maintain a moderate effort (4-5) for your workouts but a vigorous effort (6-7) for strength training. With good technique, newbies can make great strides early on. Include rest breaks between sets and concentrate on good technique.

On-and-Off: Maintain a moderate to vigorous effort for most of your workouts (5-6), and a hard effort for your strength training (7-8). You’ll achieve significantly greater health benefits!

Steady for 6 months: For 4 days per week, maintain a moderate to vigorous effort for your workouts (5-6). On 2 of the days, try increasing your effort to hard (7-8). Your strength training should be near maximal (8-9). Now you have a lifestyle that is proven to significantly reduce the risk of premature death and serious health problems.


You’ll benefit the most from your exercise by including healthy food and enough sleep each day. We know that beneficial hormones and tissue repairs occur during sleep but are hindered by sugar and vegetable (seed) oils.

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