After four weeks of lousy runs (albeit in beautiful settings), I'd had enough. I made an appointment with my PA. "Why are you being seen?" asked the nurse. "Decreased exercise tolerance," I told her, slightly embarrassed. After all, I'd run 30+ miles the previous week (slowly and painfully), and had biked to the appointment. Still, that was the problem, and that was why I was there.
Luckily, my PA was a marathoner (until she had hip replacements) and is an endurance swimmer. When I told her I just couldn't run like I had been a few weeks ago, she got it. I wasn't sure what to make of the other symptoms I'd had (leg cramps, salt craving), but mentioned those too. "Maybe it's just the heat, maybe it's overtraining, but I just want to make sure it's not something else before I ramp up again," I told her.
She did a physical exam (normal) and ordered some lab tests. We started with a reasonable set of tests for fatigue: a complete blood count, basic metabolic profile (chem-7), thyroid tests, and a urinalysis. The clinic runs some basic tests on site, so I only had to wait 10 minutes for results from the CBC, metabolic profile, and UA.
"Well, I see why you're having trouble running!" she announced, coming back into the exam room with a printout. "I think that 11 mile run with these counts was pretty heroic!" I'd had a CBC two months ago as part of my hardware removal pre-op physical, so we had a baseline to compare the numbers to. My hemoglobin had dropped from the low end of normal (11.7 g/dL) to well below normal (8.9 g/dL), a 25% drop! Hematocrit and RBC count were down similar levels, and my MCV (average red blood cell volume, which decreases in iron deficiency anemia) was still within normal limits, but significantly lower than it had been.
She added on some iron tests, which showed evidence of pretty marked iron deficiency -- my ferritin was 6.8 (normal is 10-300), iron was 14 (normal 40-150), iron saturation 2% (normal 20-50%), elevated transferrin and total iron binding capacity. Other test results, including the metabolic profile, thyroid tests, and UA, were normal.
Here's the weird thing (or maybe not): Yes, this is alarming. Yes, we're working me up for GI iron loss. But my first reaction was: I feel so validated. Four weeks of crappy running -- explained! Salt craving -- explained! General feeling of being in a funk -- explained? Maybe. With a clear diagnosis came a clear course of action.
I've started taking a funky iron + herbal supplement called Floradix, recommended by my PA. Good iron bioavailability, no bad GI effects (constipation) that iron pills typically cause. Because I don't have a diet that's obviously iron deficient (I'm still eating pretty close to Whole30, with lots of vegetables and meat, including beef 1-2x/week), we're concerned that I may be losing blood in my GI tract, so we're working that up. (It's a little bit of trouble, but beats the heck out of missing a colon cancer or gastric ulcer).
It supposedly takes two weeks to see a measurable effect of iron supplementation on blood counts. I've been taking iron for 9 days now. Hard to say, so far, whether there has been any detectable change. I ran 2 hours easy on Labor Day at Lebanon Hills, and it was fine. (The cooler weather certainly helped). Did a couple more runs this week that were so-so. I'm impatient. But now that I have an explanation for run funk, I'm also hopeful.