3 Reasons You May Feel Sick After a Marathon
New Jersey-based running coach Erica Coviello, a Road Runners Club of America (RRCA)–certified running coach and an American Council on Exercise (ACE)–certified personal trainer, has seen her athletes get wiped out post-marathon. “It could be a combination of things,” she says. “A marathon totally depletes you, and there are a few reasons why you might feel awful.”
1. Gastrointestinal Issues
Upset stomach and the need for urgent bathroom breaks are common among marathon runners.
“When you hear about people needing bathroom stops and their gut being totally destroyed, it’s usually because when you’re running the marathon, your [physical] stress levels go high,” says Coviello. “It puts you into that flight-or-fight response mode, and in doing that, your blood flow changes and your body is like, ‘What the heck is going on?’ It reroutes the blood to essential organs and away from your gut.”
This leading theory explains why you may feel nauseous or like you need to rush to the nearest portable restroom mid-race. And, according to Coviello, this response can continue on for several days after your marathon.
2. ‘Post-Marathon Depression’
Perhaps just as common as the marathon flu is the marathon blues, which is a feeling of loss and sadness following the race.
“You spend so much time and so much of your schedule regimented toward that one event,” says Coviello. “Whether you completely crush your goals or you have completely failed, that’s the climax. Then you’ve got a day or two of celebration, and then many people wonder what they’re supposed to do now.”
That void can feel like depression, and if you have already been diagnosed with a mental health condition like depression or anxiety, it can exacerbate symptoms.
“There is a real physical manifestation of that,” says Coviello. “And if that’s why you feel crappy, you have to treat it like a real thing to recover.”
3. You Have an Infection
For many reasons, the marathon flu is usually just that: a real flu, cold, sinus infection, or other virus that requires rest and care.