Minnesota air quality alert: Is outdoor exercise safe? Here’s how to tell

Published 5:09 am Tuesday, June 3, 2025

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By Catharine Richert and Gretchen Brown, Minnesota Public Radio News

Many Minnesotans looks forward to walks and runs in the state’s parks and trails this time of year, but wildfires in Canada have meant smoky skies over the past few days.

The Minnesota Pollution Control Agency issued an air quality alert for the entire state until noon on Wednesday. Air quality is expected to be unhealthy for all groups in the Twin Cities, very unhealthy in northern Minnesota, including Brainerd and Bemidji, and hazardous in far northwestern Minnesota, according to the MPCA.

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To find out what that means for your evening jog, MPR News host Catharine Richert spoke with Daniel Craighead, an assistant professor in the School of Kinesiology at the University of Minnesota.

Click on the player above to hear the conversation. The transcript below has been lightly edited for length and clarity.

Is it really that bad to go on a run or bike ride when the skies are smoky?

Part of it depends on your personal circumstances, your own health situation. And some of it depends on the air quality itself. For most generally healthy people, a little bit of smoke in the air is OK. We measure the air quality with the AQI or air quality index.

For most people, when that AQI gets to 150, it’s still OK to go out and exercise — but you want to shorten the duration of your exercise or reduce the intensity. So maybe if you were going to go for a run, you might go for a walk instead.

Once that AQI gets up to 200, that’s the point where you know exercise outdoors really should stop. But people who have pulmonary or cardiac conditions may need to move their exercise indoors at lower air quality index levels.

Athletes know weather conditions can have a big impact on performance. What are the possible impacts from bad air quality?

It’s really going to impact aerobic exercise. That’s exercises that involve getting your heart rate and breathing rate up — so going for a run, going for a bike ride, or doing outdoor team sports like soccer, for example.

When the air quality is poor, breathing becomes a little more difficult, and you can expect your performance in those sorts of sports to slip. You’re not going to be able to run as fast or as far as you would be able to on a day when the air quality was good, for example.

Some people work outside and have no choice. Others might feel like they want to risk the side effects and spend some time outdoors. Are there ways they can minimize their risk?

There are a couple things you can do. One is that you can minimize your risk from the wildfire-smoke air pollution by exercising in a place that’s free from other pollution as well. For example, near major highways, we get a lot of extra pollution from cars and trucks.

If you normally would exercise somewhere near a major roadway, try to move more into a park or someplace away from where a lot of vehicles are emitting air pollution.

Then, during the COVID-19 pandemic, we got a lot of research on what it is like to exercise wearing face masks or N95 respirators. And while it can kind of be uncomfortable and probably a little sweaty, we now actually know that you can exercise with an N95 respirator on, and it really won’t impact your exercise ability negatively.

In other words, it’s not going to make it more difficult to breathe. You could wear a face covering or a mask that could help purify the air you’re breathing in, and be able to exercise outside.