Spinning, Time, Heart Beats and Relativity

Why does time slip by so fast in spinning class.
I have been amazed how quickly it is all over.
The command, “Let’s get started”, lights down, music up and then all out, stand, climb hills, chase, flats, keep it up, more hills and then “only five minutes left in the race, let's go”.
Then cool down, another spinning class is in the books.
I would think the sheer effort of sixty minutes of cycling would drag on forever.
Einstein’s theory says the faster a body moves the slower time ticks in relation to an outside observer, so for the one spinning time should seem to elongate while everyone else outside of the spin class would age at a faster pace.
But instead, time seems to speed up in spin class and here is my theory as to why this occurs.
The heart rate trumps Einstein in this case.
All living creatures including humans have about one and one half-billion heartbeats stored in their heart at birth.
So someone with a resting heart rate of 45 to 50 (Please don’t waste the time doing the math as the approximation is good for this Blog) would live on average 70 years.
If the heart rate were doubled such as in a smaller animal the life span would be significantly shorter because you would use up your heartbeats at a much faster rate.
As an example shrews and hummingbirds have heart rates that vary between 1000 and 1400 beats per minute, thus exceedingly short life spans versus blue whales and elephants that have very slow heart rates and very long life spans.
What does this have to do with spinning and the fact that time seems to move so fast?
The answer, in spinning the average heart rate approaches 150 to 160 beats per minute.
That means you are using up your heart beats thus your life 3 to 4 times faster than when you are resting.
So during the spinning class you are actually using up four hours of heart beats within one hour and the body senses this dramatic increase in the use of life units.
The mind to protect the cycler, re-calibrates reality making the hour seem like it is really only minutes, 15 to 20 to be exact.
Somewhere in this thought is a good experiment just waiting to be undertaken.