At the end of last year I decided enough was enough and I HAD to lose weight. Since then I have lost about 3 and a half stone. I try to do 10 miles a day on an exercise bike, which takes me anywhere between 33 and 35 minutes. My bike tells me that this is roughly burning 400 calories, but I know that actual calories burned depends on many factors. Does anyone know what these are? And the amount of difference they will make?