Have I got the energy calculation correct?

Bhima
Bhima Posts: 2,145
edited November 2009 in Training, fitness and health
Energy metabolised = (Power*Time) / Your body's efficiency

So 400W in an hour would be:
400 Watts x 3600 Seconds = 1440000 Joules

Body's efficiency is 19-24%, so i'll use the average figure of 21.5%
1440000 / 21.5 = 66976.744186046511627906976744186 Joules

= 15.99712 Kilocalories

????? :shock: ?????

I've obviously gone wrong somewhere. But where? :?

Comments

  • bompington
    bompington Posts: 7,674
    It's the 66976.744186046511627906976744186 Joules figure - it's clearly not calculated with enough precision.
  • ride_whenever
    ride_whenever Posts: 13,279
    21.5% so divide by 0.215 not 21.5...

    gives you 1500kcal
    Neeermad
    Carbon 456
    456 lefty
    Pompino
    White Inbred
  • bompington
    bompington Posts: 7,674
    Or alternatively, 21% = 0. 21, so 144000 / 0.21 = 6,700,000 J = 1600 Kcal

    Impressive if you can burn that: is 400W a realistic figure for 1 hour? Probably not for me anyway.
    But at least the answer looks a bit more plausible now.
  • shockedsoshocked
    shockedsoshocked Posts: 4,021
    bompington wrote:
    Impressive if you can burn that: is 400W a realistic figure for 1 hour?

    If you're Chris Boardman, then yeh :wink:
    "A cyclist has nothing to lose but his chain"

    PTP Runner Up 2015
  • bompington
    bompington Posts: 7,674
    Never mind all that, how many bananas per hour does that come to?
  • Bhima
    Bhima Posts: 2,145
    Thanks guys. :D

    As for Banana's per hour:

    Carbs/Proteins = 4 kcal/gram
    Fats = 9 kcal/gram

    Average banana:
    Carbs: 27g = 108 kcal
    Proteins: 1.3g = 5.2 kcal
    Fats: 0.4g = 3.6 kcal

    Total = 116.8 kcal

    Therefore, 13.6986301 BPH is required.

    If you could do 400W in an hour, you could lose over a kg in bodyfat just by doing it 6 times. :shock:

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