The heart is a muscular organ which pumps blood around the body, feeding muscles and organs with the blood, oxygen and nutrients
required for their functioning. The difference between the heart and other muscles in the body is that the heart must keep working
constantly to sustain life. The most important measure of fitness relates to the performance of the heart.
The average healthy adult has between 4,5 and 6 litres of blood in their body, making up one-eleventh of their body weight. A person's
entire blood supply makes a complete circuit of the heart, lungs, blood vessels, and back to the heart every 60 seconds.
Your pulse is your heart rate - the number of times your heart beats in one minute. You can measure your pulse by placing your index
and middle fingers on the inside of your wrist. Count the number of beats for one minute (or for 30 seconds and multiply by two) and that is your pulse.
The important thing to remember about your heart rate is that if you over-exert or under-exert yourself, you won't get the best
results from your exercise. Regardless of the activity you participate in, if you exercise at a target heart rate of between 60
and 80 per cent of your maximum heart rate, you'll experience improved cardiovascular fitness. If you keep that rate slightly
lower (e.g. between 55 and 65 per cent), your body will burn fat most efficiently.
NOTE: There are various recommended ranges, including 55 to 75 per cent and 60 to 90 per cent. The 60 to 80 per cent used here is a
good guideline, but you may wish to consult your doctor or personal trainer for more specific advice.
Determining your heart rate
Here's a quick and easy way to figure out your target heart rate:
Subtract your age in years from 220. This provides the maximum number of heartbeats per minute expected for someone your age.
For example, if you're 30 years old, the equation would be 220-30 = 190.
To find your ideal exercise intensity zone, multiply the result by the lower and upper limits of your ideal range (60 per cent and 80 per
cent respectively). If you're after a great cardiovascular workout, you would multiply your maximum heart rate (our example is 190)
by 0,60 to get your lower limit (114). Then you'd multiply your maximum heart rate by 0,80 to calculate the upper limit (152).
To monitor your heart rate during your workout, put two fingers on the carotid artery (on either side of your neck), count the beats during
a six-second period and add a zero to the count to get your heart rate per minute. It should fall within your lower and upper
limits (114 and 152, as calculated above).
If you have any doubts about your fitness, always check with your doctor before embarking on a new exercise plan.