Return from Influenza

I recently recovered from the dreaded flu, and I decided to write about my experience to share with anyone else going through it. I did a lot of research to learn more about what my body was going through, and there wasn't that much out there about marathoners and influenza - plus flu strains vary each season.

My illness in bullets:

• Day 1 (2/26/24) - My throat became sore mid-day. I felt fine otherwise and chalked it up to the extreme weather changes we were having.
• Day 2 (2/27/24) - My throat soreness continued and I felt a little "off", but nothing much. I ran a workout and my positive split and the way I felt made me think I was for sure getting a cold. I skipped my planned double to get extra rest. I felt worse as the day progressed, developing a cough and headache. Knowing what I know now (see the bullet points at the end), this workout was a mistake, but there was no way I could have known with the minor symptoms that were presenting.
• Day 3 (2/28/24) - I was feeling worse but still within the realm of a cold. I cut my planned 12 miles to 8 in the morning, and ended up mostly losing my voice and working just a half day. I rested all afternoon and hoped I'd feel mostly back to normal the next day.
• Day 4 (2/29/24) - The first day of feeling like I was dying, with sore throat, severe congestion, productive cough, body aches, headache, extreme fatigue, brain fog, dizziness, and a constant sick taste in my mouth. There was no way I was going to make it to work, and I got into my doctor that morning and tested positive for Influenza. She prescribed Tamiflu. She told me not to go to work again until Monday, and it was a huge relief to have 3/1/24 off plus the weekend to recover because I felt so awful. I did not run 2/29 or 3/1. 
• Days 6-8 (3/2/24-3/4/24) - My acute symptoms improved a great deal and by 3/4/24 I had only a cough, occasional headaches, and fatigue. 
• Days 8-16 (3/4/24 through 3/12/24) - I returned to work but each day came home and went to bed shortly after work, sleeping about 6 p.m. to 6 a.m. I was able to run 3-5 miles slowly most mornings, but that was all I had. My acute symptoms were minor, with a cough, occasional headaches, and fatigue, but I couldn't kick the extreme weakness.
• Day 17 (3/13/24) - I had my first run that gave me a glimmer of hope! After not being able to make it more than 3-5 miles, I felt good doing 7, albeit still slower than "normal" easy pace.
• Day 20 (3/16/24) - I was able to do a "long" run of 12 miles, although it was slower than normal and took way more out of me than it would have pre-illness.
• Day 23 (3/19/24) - My first workout back! Also my first day with no headache.
• I have continued to get headaches off and on as I've recovered from there. Ibuprofen takes care of them but I try not to take it unless I really have to. As of today (3/24/24), I am not as strong as I was pre-illness, but it's hard to know if I'm still coming back or if I lost fitness - likely both!

I talked to my doctor, a doctor friend, and several other runners who'd had this year's flu, and learned that what I experienced was well within the realm of normal for year's flu. While that was discouraging, it was nice to know what my experience was typical. The runners I talked to told me it took them 4-6 weeks to return to normal strength and training.

I have trained through many illnesses, including walking pneumonia, bronchitis, and cryptosporidium. I'm not saying this is advisable, but I've done it. I took 3 days off each time I had COVID, mostly as a precaution. I simply could not train through this. I took 5 days completely off, but had 16 additional days of very reduced activity.

The upside was that once I improved, I improved pretty quickly. I had no improvement in weakness for 2 weeks, which was the hardest part for me! But once I started feeling better I was able to get back to relatively normal running reasonably quickly. I did 75 miles with 2 workouts and a 16 mile long run the week of March 18, so thing have turned around.

Two articles that I found helpful:

This one is a faster read. The most interesting part to me was an explanation of a study in which mice were infected with influenza and 3 groups were compared: no exercise, moderate exercise (20-30 min./day) and prolonged exercise (2.5 hours/day). The group who did moderate activity fared the best, no activity was in the middle, then prolonged activity had the worst outcome. Based on this I decided my easy 3-5 milers were better than not running. Long runs were off the table, but I didn't have the strength to do one of those if I wanted to anyhow.

This one is longer and compares recovering from the flu to recovering from a 100 miler! I learned a lot here, including:

• The flu virus directly infects then destroys muscle cells. The effect is similar happens in ultra-marathons, and the body aches are due to muscle cell infection, and possibly destruction (my muscles felt this!).
• Some flu strains cause cytokin overload, where healthy immune systems go into hyperdrive and overload - the stronger the immune system, the more severe the reaction (meaning it strikes hardest in those with the strongest immune systems who are the healthiest to begin with).
• Exercise during early infection (before your body develops virus-killing antibodies) is the most detrimental. The increase in body temperature from exercise facilitates greater viral spread (this is why I wish I hadn't worked out when this began).
• Resuming hard running and racing shouldn't occur for 2-4 weeks, or for most for 4-8 weeks (eek).

First group run back!