Fitness Makeover Day 12: Please turn around!

My boyfriend thought I was crazy tonight.  We went for an 8:30pm walk (hey, he asked!).  During the walk, I decided to do this:

• 800km walking forward
• 400 km walking backwards 
• 800km walking forward
• 400 km walking backward

It was a total of 2400 km.  All I have to say is that walking backwards has a totally different feel and I felt different muscles working.