I finally had my doctor check out a small nagging pain in the ball of my right foot. I've had it for months and I even quit wearing high heels to try to heal it. The switch in shoes has helped somewhat, but racewalking still aggravates the condition. At least now the pain doesn't commence until racewalking for more than 50 minutes.
The good news is it is not a stress fracture. It's metatarsalgia! A few of the causes include wearing high heels, intense training, wearing shoes with little padding, and aging. Hmmm -- I wonder which of these apply to me?
Additional good news: treatment includes wearing metatarsal pads in my shoes to relieve pressure off those bones. I think I can do that.