Let’s begin with a scientific principle which goes like this:
‘Every person requires the same amount of oxygen to perform a particular activity. The fitter you are, the slower your heart needs to beat to supply blood (and therefore oxygen) to the working muscles. Firstly, the cardiac output or the volume of blood pumped from the heart with each beat, is increased as you become fitter. Also the muscle cells use the oxygen more efficiently.’
To illustrate this point two people – one fit and the other unfit – were made to ride on stationary lab bikes. These bikes are called ergometers, since ‘ergo’ means work. The force which is needed to pedal the machine is the work load. This work load is measured in units called kiloponds (kp).
Both people rode the ergometers for 9 minutes at different work loads: namely, 300, 600 and 750 kpm (kilopond meter) respectively over successive three minute intervals. A lab assistant recorded their heart rates at the end of each three-minute period. See table below for the results.
Notice how the heart rate of the unfit individual is much higher. Their heart is being made to work much harder. It is less efficient than that of the fit person whose heart beats much slower. Their heart doesn’t have to work hard to supply the necessary oxygen for that activity.
For the next nine minutes they rested. Their heart rates were recorded again at the end of each three-minute period. The second part of the table shows these results. The fit person’s heart recovered to its resting rate much faster. Even at the end of the nine minutes the unfit person’s heart hadn’t returned to its normal resting rate. Thus, the fitter you are, the better your body will function and the better you will feel.
The difference between the heart rates of fit and unfit people.
If we take the difference in the heart beats before any activity – 25 beats per minute, the figures are staggering.
Difference:
25 beats per minute
1,500 beats per hour
36,000 beats per day
252,000 beats per week
13,104,000 beats per year
No related posts.
You must be logged in to post a comment.
