Backward walking for more calories burned

Researchers discovered that walking backward burns 25% more calories compared with forward walking. This is due to the faster pace of the steps of the backward walking. Researchers also say that this type of walking increases the heart rate by 47% and the oxygen use by 78%, compared with normal (forward) walking. (based on materials from Men's Health)
From this I can conclude that the same most likely holds true for the backward running, compared with forward running.