On 17/03/2014 20:09, Chris wrote:
The gym has machines by pulsefitness.
There seems to be a mismatch in the numbers displayed.

After a bike session the summary was:
Power average: 74 Watts.
Time taken: 9 minutes.
Energy used: 50 kcal.

The above energy figure would equate to 333 kcal per hour.
But 100 Watts is only 86 kcal per hour!

The mismatch is so enormous that I feel I must have missed something.
I would be grateful to any physicist who can shed light on the figures.

The figures are fine, its just your body can't do a 100% efficient
conversion of stored chemical energy into mechanical power. So the
energy consumption by the body will be several times the plain
mechanical output (it will waste a good amount just producing heat for
example)


--
Cheers,

John.

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