We learned that 30 minutes of exercise each day burns more fat than 60 minutes of exercise each day. 

It seems a little too good to be true, but a Danish study found that moderately overweight men who ran, biked or rowed for 30 minutes and burned 300 calories every day lost an average of 7.9 pounds over 13 weeks.  A second group of men who exercised for 60 minutes and burned about 600 calories every day lost only an average of 6 pounds. in the same 13 weeks.  Both groups measured about the same amount of fat lost, 8.8 lbs. in the 30-minute group and 8.3 lbs. in the 60-minute group. 

Researchers posit that the group that exercised less may have been more active in other forms of physical activity that the study did not measure.  Or perhaps the group that exercised more ate more as a result, though within the study there was no difference in caloric intake between the two groups.

Whatever the reason, more exercise does not always mean more weight lost.