Day 15: Soccer takes its toll

I never did get my "fitness walk" in yesterday, despite the decent weather. I figured playing soccer with the resident 3-year-old would suffice. We chased a couple of soccer balls around the backyard for half an hour, leaving him with pink cheeks and me a bit winded.

It wasn't until a few hours later, while I was in town doing a little Christmas shopping, that my knees started to ache. In fact, I had to cut short my shopping trip -- which is probably just as well. I headed home, vowing to find a more low-impact way to get myself moving.

My mother has arthritis in her knees and hips. That's why, at 97, she spends most of her day in a wheelchair. She hates to take pills, so she's often in pain.

Thinking of her is one of my best motivators to get in shape. So is reading recently on WebMD that for every pound of body weight an overweight person sheds, there's a 4-pound reduction in stress on the knee joint.

Talk about motivation.