The tutor reflects on the percent power needed for an effective workout.

Back in my June 5, 2015 post I calculated that, according to the exercise bike, I can produce 1046.5W for twenty minutes.

What if I do a skipping workout? Let’s compare the power used skipping to riding the bike.

I’d say I do about 2 jumps per second, and that each one is 1.5cm in height. Absorbing the shock coming down is about the same as jumping up, so let’s imagine the equivalent of 4 jumps per second of 1.5cm, giving a change in height of 6cm (0.06m) per second. My mass is 82kg. To find the work done, we use

Work = Force x distance = mass x gravitiational constant x height

For this specific case we have

Work = 82×9.8×0.06 ≈ 48 Joules of work done every second. A rate of 48J/s means 48W.

So, skipping, my percent exertion is 48/1046.5 ≈ 4.6% compared to cycling; I knew it would be a lot less. Yet, skipping will definitely continue to improve my condition. Therefore, an exertion rate of around five percent seems adequate for progress in a fitness regime.

I’ll be talking more about exercise and fitness in future posts:)

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.