There are some mysteries in life that I will never solve. How urine ends up on the wall opposite the toilet, for example. And why people fear world dominance by redheads while simultaneously labeling us “endangered.” Or how our tabby cat learned to open locked doors. (Not kidding!) Maybe Sherlock Holmes could get to the bottom of these strange phenomena, but not me.

So when I quite suddenly began experiencing pain in both Achilles tendons, it was no surprise that I couldn’t pin-point a reason. Initially I blamed the training I was doing in preparation for a 5K against my kids. (And yes, I was absolutely competing against my children, especially the 6’2” brat who thought he could beat his mom. Like that would ever happen.) But even weeks after the race, when I’d cut back on my mileage, I still had trouble taking my first steps in the morning, climbing stairs, and even driving the mini-van.

Then I thought it was because I’d changed from New Balance shoes to Saucony, though I’d had great luck with this brand in the past. And switching back to my old ones brought no improvement. As the months wore on and the heel pain worsened, I was forced to consider the possibility my body was growing old, and none too gracefully. That too much damage had been done in my glory years and I’d have to quit running forever.

One evening, as I was lamenting a sad fitness future of geriatric water aerobics, a light went on: I sleep on my stomach. And my pain began within a few days of our new mattress purchase. An ultra-firm mattress. I realized that I spend eight hours every night with, what boils down to, pointed toes. No wonder my Achilles were killing me!

To test my theory, I slept the next couple of nights with my feet hanging off the end of the bed. Almost immediately, the soreness and tightness disappeared. A week later, all pain was gone, even while running.

My discovery was far from elementary, but at least I solved one mystery. Peace out.