We've all heard the exercise
guidelines that recommend we participate in 30 minutes of moderate intensity
physical activity 3-5 times per week. That seems easy enough to implement. Or,
does it? The duration and frequency guidelines are very straight-forward and
easily defined. But, "moderate" intensity is often left to interpretation. So,
how do we define "moderate"?
First we need to understand
that the definition of moderate intensity can be completely different from one
individual to another. For example, a well-trained athlete may be in the
moderate zone when running 5 miles in 30 minutes. Yet, for a novice exerciser
who is very overweight, moderate means walking one mile in 30 minutes.
Don't let this confuse you.
While the intensity level is very critical in the overall guideline,
fortunately it's also fairly easily identified. The ACSM (American College of
Sports Medicine) defines moderate as an intensity of 40 percent to 60 percent
VO2 maximum. But, since most of us don't know how to determine our VO2
maximum, there are easier definitions to utilize.
You can base VO2 loosely on
your maximum target heart rate zone. A VO2 maximum of 40-60% equates to about
50 to 70 percent of maximum heart rate (MHR). And determining your MHR and the
corresponding percent zones is relatively simple. Below is an easy calculation
for determining your specific MHR and what 50-70 percent of equates to.
- Take 220 and subtract your age.
This equals your MHR. (Example: For a 30 year old your MHR is 190)
- Next to determine your low range of
50 percent, simply take 190 and multiply it times 50 percent. (Example: For
a 30 year old this would equal 95).
- Finally, to determine your high
range of 70 percent, simply take 190 and multiply it times 70 percent.
(Example: For a 30 year old this would equal 133).?
So, in this example the 30
year-old would want to exercise in a heart rate range of somewhere between 95
- 133 BPM. Keep in mind that this calculation is age-related. It does not take
into consideration your fitness level. So, it is not completely accurate, but
still a good guideline. For an even more accurate (and more complicated)
method for determining your training intensity range, visit this link:
Also, some medications can
raise or lower your heart rate and change the heart's response to exercise.
Beta-blockers are among those that alter the heart rate. This means that
people taking these types of prescriptions should probably use another option
for monitoring their intensity.
There are some other very
good ways to measure intensity for both people taking medications or those
just looking for a more convenient method. Two good options are the Ratings of
Perceived Exertion (RPE) method and the Talk Test.
This takes into account what
the exerciser is perceiving in terms of exercise fatigue and it correlates
well with cardiorespiratory and metabolic factors like heart rate and overall
fatigue. The RPE scale starts with 0 and ends with 10. A rating of 0 equates
to doing nothing, being at rest. A rating of 10 is equal to maximum effort,
working very, very hard. For moderate intensity, an exerciser should strive
for reaching somewhere between a 4-6, which the scale defines as a somewhat
hard to a hard effort.
A great way to measure
intensity (where appropriate), is utilizing both the RPE and Target Heart Rate
Zone. The exerciser should identify where they fall on the RPE scale when
their heart rate is between 50 - 70% maximum. This will allow them to
accurately use only the RPE scale for measuring intensity when it is not
feasible to determine their THR.
The final method for
measuring exercise intensity is the Talk Test. Like the RPE, the talk test is
subjective. The exerciser simply ensures that he works out at a level where he
can carry on a comfortable conversation. He should be able to breathe
comfortably during exercise. In simple terms, the exerciser would be working
out too hard if he has to take a breath between every word he says. On the
flip side, he would be exercising at too easy of an intensity if he could sing
several phrases of a song without breathing hard.
Now you know how to define
"moderate" and that means you don't have any more excuses. It's time to get
moving. Keep in mind that the ACSM guidelines are minimum recommendations. For
more significant health improvements and/or weight loss or for more advanced
exercises, consider increasing any part of the three recommendations found in
Lynn Bode, author
and certified personal trainer, offers her services online through
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