Strava said I burned 799 kCal on a recent ride.
Then Strava says I output 456 kjoules.
But if I remember my conversions, 1 kCal ~ 4.2 kjoules; I calculate ~3345 kjoules. Which would be an output ~ 670 watts.
As far as I remember, I did not just win the Tour de France, so I kind of doubt that. (Maybe I should enter next year???)

What am I missing (other than my yellow jersey)?