Target Heart Rate

Monitoring your heart rate is a method used to measure cardiorespiratory
exercise intensity.  Your Target Heart Rate zone is generally
considered to be between 55% and 90% of your maximum heart rate.  It is in
this range that research suggests we benefit most from cardio exercise.

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Heart rates fluctuate with work load, the harder you work
the higher your heart rate.  Keeping your
heart rate in the “zone” helps to strengthen your heart (the heart is a muscle
like any other and responds to training in the same way).  Where in this range you exercise is dependent
upon your fitness level and experience with training.  A beginner will not train in the same way as
an advanced athlete and as well, a 20 year old will not train at the same heart
rate as a 60 year old.  The chart below
shows suggested intensity levels for beginner, intermediate, and advanced
trainees.

There are generally two methods used to calculate your
target heart rate, the percentage of
maximum heart rate and the heart
rate reserve method.  I will attempt (using
my fine grammar and writing skills…..did I say I was a writer?) to explain
both.

When calculating your target heart rate the first thing you
must calculate is your maximum heart rate (the highest heart rate an individual
can safely achieve through exercise). 
The most common method used to calculate your heart rate maximum (HRmax)
is to subtract your age from 220.  In
other words HRmax = 220 - your age known as “age adjusted” maximum heart rate.  Many people cite 220 as the base number for
men and 226 for women.  This may be the
most common method used to determine HRmax but it is not the most consistent or
accurate, just a good starting point and a means to keep track of improvement -
there are way too many variables that contribute to calculated maximum heart
rates.  

Okay so how do we calculate our target heart rate
range? 

The Percentage of
HRmax method;

1)     
Calculate your max heart rate

2)     
Find your percentages in the chart below

3)     
Target Heart Rate(THR) = HRmax x %  lower

4)     
THR = HRmax x % upper

5)     
THR = the range between upper and lower as
calculated above

For example, Bill is 30 years old and has never exercised
before.  Bill’s HRmax = 220 – 30 = 190
beats per minute.  From the chart below
it can be seen that Bill’s target range is between 55% and 64% of his maximum
heart rate, therefore THR lower = 190 x .55 = 105bpm and THR upper  = 190 x .64 = 122bpm.  Bill’s target heart rate zone is between
105bpm and 122bpm.

 

Cardio Training Guidelines

Description	Beginner Very low to low fitness	Intermediate Average fitness	Advanced Above average
Intensity	55%  -  64%	65% - 74%	75% - 90%
Frequency	1 – 3 times per week	3 – 5 times per week	4 – 6 times per week
Time	10 – 30 minutes	20 – 45 minutes	40 – 60 minutes

 

The Heart Rate Reserve method takes your resting heart rate (RHR) into account
and also takes fitness level into consideration, the more fit you are the lower
your RHR.  The fitter you become through
exercise the lower your RHR and the higher your target heart rate zone.

 

The Heart Rate
Reserve method:

1)     
Check your heart rate first thing in the morning
before and physical exertion, preferably before you get out of bed

2)     
Calculate your HRmax

3)     
Find your percentage range in the chart

4)     
THR = [(HRmax – RHR) x percentage] + resting
heart rate

 

Using Bill as our example again we already know that Bill’s
HRmax = 190.  Bill’s RHR (resting heart
rate) is 75bpm.   Using the formula
above; THR = [(190 – 75) x .55] + 75 = 138 and THR = [(190 – 75) x .64] + 75 = 149.    So in
this case Bill’s target range is 138bpm to 149bpm.  This is somewhat higher than the percentage
of max method so which is correct? 
Basically the heart rate reserve method is geared more for people who
know their resting heart rate, tend to be fit, and know their cardiorespiratory
fitness level.  It should also be stated
that as you become more fit and your resting heart rate lowers so shall your
lower target heart rate.  It is important
to know all variables when using this method, you certainly don’t want to work
less as you become more fit.

No matter which method you use there will be inaccuracies.  The key is to make sure that you are working
hard, breaking a sweat, and sustaining this intensity for durations of at least
10 minutes.  Health Canada suggests cardio
on most days of the week (4 to 7) for a minimum of 10 minutes.  As a beginner you don’t ever want to max out
your heart so stay below but keep in mind that the maximum heart rate can be deceiving
when dealing with extremely fit people -  their max heart rate might be higher.  Calculations are an approximate at best.

Two last things I should mention:

1)     
You should always consult your doctor before
beginning any fitness program.

2)     
If you are serious about your fitness you should
buy a heart rate monitor