Article Please? wrote:
I am not, although rekrunner and many others may take it that way. I’ve got about 15 years of experience using a power meter and am pretty handy with numbers so have a great deal of confidence in what’s I’ve stated here.
That may be - but you have both the science and the numbers wrong.
Article Please? wrote:
I question whether it was really 650kcal, as that is much more difficult to measure than 650kj. I question whether it was really 650kcal, as that is much more difficult to measure than 650kj. The fact they are measuring power output would lead me to believe they are in fact saying 650kcal but really were having them do 650kj. Measuring the amount of calories an athlete is using is very difficult, whereas measuring the kj's is very easy when you have a power meter.
650kj would be attained at 213w in 50 minutes and 51 seconds. 650kj at 223w takes 48 minutes and 35 seconds.
Both kJ and kcal are units of energy, therefore one is not more difficult to measure than the other.
1 kcal = 4.184 kJ
The authors used the good old fashioned kcal; your assumed 650 kJ are only 155 kcal.
The cyclists spend 650 kcal in 40 minutes, so your estimate of 155 kcal in 48 - 52 minutes is way off.
Article Please? wrote:
Remember that is not measuring a distance, but amount of energy output. When it comes to cycling on flat ground remember Pi, which is ~3.14. A 10% increase in power will net approximately a 3.14% increase in speed on flat ground.
I literally lol'ed when reading this argument. Just because the circumference of the wheel is 2 x pi x r does not mean that
relative power increase = pi x relative speed increase / 10
The numbers also don't work out here: 4.7% more power translated into 4.4% faster. According to your formula, it should have been 1.5%.