Today's air quality & heat
1 - AQI BAND
0-50
Good
51-100
Moderate
101-150
Sensitive
151-200
Unhealthy
201-300
Very Unhealthy
301+
Hazardous
⚠️
Symptoms override the plan. Chest tightness, wheezing, dizziness, or heat-illness signs mean stop — no matter the number.
STEP ONE
Check live Eugene conditions first
Heat and smoke are separate stressors, so look at both. These panels connect to live data for Eugene — check them before you use the decision table. It may be best to make the call at the trailhead or workout location as conditions can be variable.
This guide is educational and does not replace individualized medical advice. If you have asthma, heart or lung disease, a history of heat illness, are pregnant, are recently ill, or have symptoms that concern you, get personalized guidance before training in heat or smoke.
STEP TWO
Three questions before you head out
What is the current AQI?
The Air Quality Index from EPA's AirNow gives a category-based way to gauge risk. In wildfire smoke, fine particles (PM2.5) are the concern. Exercising, you breathe more and often through your mouth — increasing what you take in.
How hot does it feel?
Heat stress isn't only temperature. Direct sun, pavement, humidity, low wind, dehydration, medication, poor sleep, and recent illness all make a session harder than the forecast suggests.
How hard is the session?
An easy walk, a recovery spin, a long run, intervals, and a race effort are not the same exposure. The longer or harder the session, the more conservative your decision should be.
STEP THREE · THE CORE CALL
Train, modify, move indoors, or stop
The AQI bands follow EPA AirNow categories. The training actions are Zenith's practical guidance for active people, not EPA recommendations. Use the most conservative row that applies to you.
CURRENT | CONDITION | WHAT IT MEANS FOR TRAINING | BEST ACTION |
|---|---|---|---|
0-50 | Good | Generally favorable for outdoor activity if heat and symptoms are also okay. | Train normally or follow the planned session. |
51-100 | Moderate | Most people can still train outside, but very sensitive people may need to limit exertion. Hard or long sessions deserve caution. | Train normally if low-risk and feeling well. Modify if sensitive, symptomatic, or doing intensity. |
101-150 | Sensitive | Sensitive groups should limit exertion. Longer or more intense workouts are a poor fit for many people. | Reduce duration or intensity. Move harder sessions indoors — especially sensitive groups and youth athletes. |
151-200 | Unhealthy | Everyone should reduce long or intense outdoor exertion. Sensitive groups should avoid it. | Move training indoors when possible. If outside is necessary, keep it short and easy. |
201-300 | Very Unhealthy | Outdoor activity carries higher concern for everyone, especially sensitive groups. | Move indoors or reschedule. |
301+ | Hazardous | Outdoor physical activity is not appropriate for training. | Do not train outdoors. |
Consistency is built over weeks and months. One modified session isn't a failure - it's often the decision that lets you keep momentum.
WHY IT MATTERS
Heat and smoke are different stressors
They often show up in the same season, but they challenge the body in different ways. They don't cancel out.
Heat raises cooling demand
Blood shifts toward the skin, you sweat more, and heart rate climbs at a pace that would normally feel easy. Risk rises when:
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The workout is long or intense
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You're training in direct sun
-
You aren't heat-acclimated
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You're dehydrated or under-recovered
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You're coming back from illness
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You take medication affecting heat tolerance, hydration, heart rate, or sweating
-
You have a history of heat illness
Smoke changes what you breathe
Fine particles reach deep into the lungs (OHA). Exercising, you breathe more and faster. Risk rises when:
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AQI is elevated and PM2.5 is the main pollutant
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The workout is long, hard, or outdoors a long time
-
You have asthma, heart or lung disease, allergies, or other sensitivity
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You're a child, older adult, pregnant, or recovering from illness
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You notice coughing, chest tightness, wheezing, dizziness, or shortness of breath
MAKE IT SPECIFIC
Adjust for your sport and situation
The same AQI categories apply, but intensity and who's training change the call.
Running when AQI or heat is high
Runners feel environmental stress quickly — running raises breathing rate, heart rate, and body temperature. Adjust before you're forced to stop.
SMART MODIFICATIONS
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Move the run earlier if heat is the main issue
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Choose shaded routes with easy bailout options
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Swap a long run for a shorter easy run
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Replace hills, tempo, intervals, or race pace with easy aerobic
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Use a treadmill for quality work when smoke is present
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Carry fluids when heat is a factor
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Stop if symptoms show up
MOVE INDOORS WHEN
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AQI is Unhealthy or worse
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AQI is Unhealthy for Sensitive Groups and you're sensitive, symptomatic, or planning intensity
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Smoke is visible or you smell it and conditions change fast
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Heat is high and you can't avoid sun or pavement
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You feel chest tightness, wheezing, dizziness, chills, confusion, or unusual fatigue
⚠️Warning signs: when to stop
Stop the session if you notice any of these:
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Chest pain or pressure
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Wheezing or chest tightness
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Nausea or vomiting
-
Severe headache
-
Palpitations
-
Severe shortness of breath
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Dizziness, faintness, or confusion
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Chills, goosebumps, or stopped sweating in heat
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Unusual fatigue, out of proportion to the effort
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Coughing that worsens during smoke exposure
Seek urgent medical care for severe symptoms, chest pain, fainting, confusion, signs of heat stroke, or breathing difficulty. If milder symptoms keep returning during heat or smoke, get individualized guidance before continuing hard training.
DON'T LOSE THE DAY
Indoor alternatives that still support training
Match the substitute to what the workout was meant to accomplish.
Easy aerobic day
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Treadmill walk or run
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Easy bike trainer
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Elliptical
-
Low-intensity rowing
-
Mobility circuit
Hard workout
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Indoor bike intervals
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Treadmill intervals (if A/C is adequate)
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Strength training
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Technique work
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Delay 24–48h if quality matters
Long run or ride
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Shorter indoor aerobic
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Split session
-
Strength + easy aerobic
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Recovery day, then the long session when clear
Returning from injury
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Strength work
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Mobility and control
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Return-to-run drills
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Balance or tendon loading
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A lower-risk aerobic option
Eight rules that keep training safe and consistent
Reduce before symptoms force you to stop.
If AQI, heat, or effort trends the wrong way, shorten, slow down, or move indoors.
Use AQI categories, not guesswork.
Match the band to the workout type and your risk factors.
Symptoms override the plan.
Chest tightness, wheezing, dizziness, or heat-illness signs end the session.
Don't chase missed workouts.
Return gradually so one lost session doesn't become a setback.
Treat smoke and heat as separate stressors.
A day can be fine for one and poor for the other.
Move quality work indoors when questionable.
Intervals, hills, tempo, hard rides, and long efforts create more exposure.
Be conservative with youth and sensitive groups.
Plan around the highest-risk participant, not the strongest.
Get guidance if symptoms persist.
Recurring symptoms during heat or smoke are worth a clinician's eyes.
Not sure how to adjust your training?
Whether you're returning from injury or prepping for a race through Eugene's summer conditions, Zenith helps you keep training without guessing. Depending on your needs, that can include:
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Mobility and recovery work
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Return-to-run or return-to-ride planning
Frequently asked questions
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