Endurance Athlete
Sc ientifically Designed Athletes
Adjusting Training to Poor Air Quality and Forest Fire Smoke
Endurance Training when the air quality is bad due to forest fires.
It is a reality that many athletes in Western North America have been dealing with for several years now, but athletes in the Midwest and East all experienced poor air quality due to forest fire smoke at some point this summer. With the increased occurrence of forest fires and their size, forest fire smoke will be part of our weather and variables to consider when we are planning our daily training. Here we will cover some important topics regarding air quality and how to approach training when the air quality deteriorates.
Air Quality
The air quality can be influenced by many things: allergens, ozone, fine particulate matter, etc. With the increase in forest fires, we are seeing an increase in days with bad air quality due to fire smoke and fine particulate matter. Particulate matter and ozone are ranked on the Air Quality Index (AQI) on a numerical scale between 0 and 500 (however we are starting to
see AQI measurements above 500 in areas very close to active forest fires). To find out what the AQI in your area is there are several online resources that will give you current readings. We regularly use purpleair.com and airnow.gov to check current air quality in areas where athletes are training to help plan their training and make adjustments when the AQI gets too high.
Training in poor air
During training sessions, athletes increase their respiratory rate and can breathe in 10-20x more air than when sedentary during a given period. This means that when the air quality is poor, athletes will be inhaling a lot more particulate pollution. Knowing what the different air quality ratings are and what they mean can help make decisions about how to adjust your training at different AQI scores.
The US Environmental Protection Agency (EPA) has created a scale using AQI to provide recommendations for everyone exposed to different AQI levels. The different categories are based on AQI scores. For most athletes training when the air quality is “Good” or “Moderate” (AQI < 100), there is limited risk of training outdoors. At these levels, we normally do not make changes to an athlete’s training program.
When the AQI exceeds 100 we start to consider how the air quality is going to influence our athletes and their training. An AQI value of 101 – 150 is considered “Unhealthy for Sensitive Groups” according to the EPA. What this means is that people with heart or lung disease, older adults, and children should reduce prolonged or heavy exertion. So, for our athletes that fall into these categories, we definitely adjust training recommendations and usually suggest that they take all their training indoors. At this risk level, we also advise all athletes to consider making some adjustments to their training. Our normal recommendation is for athletes to decrease the intensity of any outdoor training session and at the higher AQI values in this range, we will also recommend they shorter their workouts.
The “Unhealthy” level is when everyone may begin to experience some health effects. This is when the AQI is between 151 and 200. It is at this level that we encourage athletes to do no training outdoors and to limit their time outside for any reason. So, at this level, we move all training sessions for our athletes indoors and we highly recommend that they have a room air filter (ideally a HEPA filter) in the room they are training in. If our athletes must do some training outdoors (i.e., they only have access to an outdoor swimming pool) we keep these workouts shorter than 30 minutes and keep intensity very low. We have also found that at these AQI levels that our athletes experience some general effects of poor air quality in their daily life. Many of our athletes complain about persistent headaches, poor sleep, and scratchy throat. These can be common effects of being exposed to this level of air quality and can influence training quality as well as recovery. For this reason, once the AQI exceeds 150 we suggest that our athletes be very aware of their exposure to outside air and how they are feeling throughout the day.
Once the AQI exceeds 200 the EPA has two categories of “Very Unhealthy” and “Hazardous”. 
Both of these levels of air quality indicate that all people will experience health effects. This is when we say that all outdoor training must stop and we suggest that our athlete limit their time outdoors and even wear an N95 mask at all times outside. Fine particulate matter in the air can damage not only lung tissue but also get into the blood and cause damage to the circulatory system. This is why we suggest no outdoor training and very limited direct exposure to outdoor air. Additionally, if an athlete does not have a HEPA indoor air purifier we restrict their indoor training as well. Therefore, if you are in a region of North America (the West, Pacific Northwest, and Rocky Mountain regions) we strongly encourage having an indoor air purifier so that you can decrease your exposure to harmful air when the AQI spikes to these levels.
Below is a summary table of our recommendations for adjusting your training at different AQI levels. With the increased incidence and severity of forest fires, it will be a more regular occurrence that adjustments to training programs will have been made based on air quality. Every athlete is unique and responds differently to poor air quality, but we all need healthy lungs and circulatory systems to not only be healthy but also perform at our highest abilities. Being aware of air quality and being smart about adjusting your training to match the air quality is something everyone needs to consider.
For all individuals and athletes, we recommend consulting with your personal physician before starting any exercise routine and especially when considering what levels of AQI are safe for you to exercise in.