There are two ways to track the intensity of aerobic activity: absolute intensity and
Absolute intensity is the amount of energy expended per minute of activity. A MET
(metabolic equivalent) stands for the amount of oxygen you consume and the number
of calories you burn at rest. The energy expenditure of light-intensity activity,
for example, is 1.1 to 2.9 METs. Moderate-intensity activities expend 3.0 to 5.9
METs. Walking at three miles per hour or 100 steps per minute has an intensity
of three to four METS. The energy expenditure of vigorous-intensity activities is
six or more METs. Walking 130 steps per minute is considered vigorous physical
activity. Running at a 10 minutes per mile pace is equivalent to 10 METs. It is also
possible to use watts, a measure of power as an objective gauge of energy output.
Various fitness machines will provide an indication of watts expended at any moment
during a workout. A beginner cyclist might average 70 to 75 watts whereas
a Tour de France professional could reach an average of 350 to 375 watts over an
hour. The ability to produce watts per body weight of a person is one measure of
Relative intensity is the level of effort required to do an activity. Less fit people
generally require a higher level of effort than fitter people to do the same activity.
Relative intensity can be estimated using a scale of 0 to 10, where sitting is 0, and
the highest level of effort possible is 10. Moderate-intensity activity is a 5 or 6.
Vigorous intensity activity is a 7 or 8.
When using relative intensity, people pay attention to how physical activity affects
their heart rate and breathing. As a rule of thumb, a person doing a moderate intensity
aerobic activity can talk, but not sing, during the activity. A person doing a
vigorous intensity activity cannot say more than a few words without pausing for
This blog presents opinions and ideas and is intended to provide helpful general information. I am not engaged in rendering advice or services to the individual reader. The ideas, procedures and suggestions in that are presented are not in any way a substitute for the advice and care of the reader’s own physician or other medical professional based on the reader’s own individual conditions, symptoms or concerns. If the reader needs personal medical, health, dietary, exercise or other assistance or advice the reader should consult a physician and/or other qualified health professionals. The author specifically disclaims all responsibility for any injury, damage or loss that the reader may incur as a direct or indirect consequence of following any directions or suggestions given in this blog or participating in any programs described in this blog or in the book, The Building Blocks of Health––How to Optimize Your Health with a Lifestyle Checklist (available in print or downloaded at Amazon, Apple, Barnes and Noble and elsewhere). Copyright 2021 by J. Joseph Speidel.