1. The problem statement, all variables and given/known data On a typical stage the riders conserve energy by staying in the pelaton. This greatly reduces aerodynamic drag on all riders except the ones at the front. Pelaton riding requires only about 60% of the power of needed for a time trial. Suppose a typical pelaton rider's power output averages 250 watts for a 5 hour stage. The human body is about 25% efficient at converting chemical energy from food into work. Estimate the total daily Calorie input from food needed for a Tour rider to maintain weight. 2. Relevant equations In a previous problem it told us that a normal person Basal Metabolic Rate is 100 watts. So that would be then 100J/s and 360000J/hr. There are 4180J per kcal or calorie. now what i am having a problem with is that when i go to find the ammount of calories i come up with only 2710.55 calories by doing 250w=250J/s=900000J/hr so while they are biking they are losing 215.31 kcal per hour or a total of 1076.55 kcal in the 5 hour bike ride. Then i just figured out the amount of calories burned at a normal persons BMR and added them giving me the total i had stated before of 2710.55 which does not sound like enough to me and i wanted to make sure that i am actually doing it right. i checked online and it said that the people while doing a bike race can consume between 8000 and 10000 kcal per day just to keep at weight so i am guessing i messed up somewhere. I am not sure who the % come in and help with this equation.