Assume running consumes 107 calories per mile. if you run 11-minute miles, what is your average power output, in watts, during a 11-hour run

Note that 1 cal = 4.184 J
                 1 W = 1 J/s

The given calorie consumption rate is
 107 cal/mi 

In running 11-minute miles,  the energy expenditure rate is
(107 cal/mi)*(1 mi/11 min) = 107/11 cal/min = 9.7293 ca/min
                                        = (9.7293 cal/min)*(1 min/60 s)
                                        = 0.1622 cal/s

Because 1 cal = 4.184 J, the energy expenditure rate is
(0.1622 cal/s)* (4.184 J) = 0.6786 J/s
                                       = 0.6786 W

In an 11-hour run, the total time is
(11 h)*(3600 s/h) = 39600 s

Total work done is(0.6786 J/s)*(39600 s) = 26873 J = 26.873 kJ

Average power output = 0.6786 W
Total work or energy   = 26.87 kJ (nearest hundredth)