I’ve worked out a formula based on speed, weight and time to get a rough estimate of calorie burn for my cycling trips. Interestingly, it hits a bit of a plateau in the middle speed ranges, as shown below. If my calculations are correct, then, I can take it a bit easier going in without hitting a calorie penalty (or, hopefully, needing a shower). On the way home I can boot it, make up the time from the morning, and hop straight into the pool to refresh myself. Win/Win/Win/Win. 🙂

dist (km) 20
spd(km/h) 15 17 20 25 30 32 35
Calories 556.81 737 835.49 835.21 835.17 913.5 954.46
hours 1.33 1.18 1 0.8 0.67 0.63 0.57

Note that I have correlated these calculations with my heart rate monitor (which is probably using a variation of the same formula, since I worked mine out from plotting various responses from different “Calorie counting” Web sites). Bonus points if you can tell me how much I weighed when I made this graph!