Wildfire Smoke Playbook for Runners & Cyclists
Practical rules for training during smoke events: when to go indoors, how to protect your lungs, and how to recover after exposure.
Quick Answer
Wildfire smoke is often dominated by PM2.5 and can push AQI from Good to Hazardous within hours. If you can smell smoke, local air may already be unhealthy for exercise. Move indoors, close windows, and wait for conditions to clear before resuming outdoor training.
This is general guidance, not medical advice. Consult a healthcare provider if you have respiratory or cardiovascular conditions.
Why Wildfire Smoke Is Different
Urban air pollution tends to be predictable — it follows traffic patterns and weather cycles. Wildfire smoke is different. It can arrive suddenly, blanket an entire region, and persist for days or weeks. The particles are also different in composition.
What Makes Smoke Worse
- Extreme PM2.5 spikes: Wildfires can push PM2.5 from 10 to 300+ µg/m³ in hours, far beyond normal urban pollution.
- Toxic particle cocktail: Smoke particles carry compounds from burning vegetation, structures, and synthetic materials — not just carbon.
- Unpredictable shifts: Wind changes can clear smoke in an hour or bring it back just as fast. Forecasts help but aren’t perfect.
- Wide geographic reach: Smoke from distant fires can travel hundreds of kilometers. Your city may have no fire nearby but still have hazardous air.
Because PM2.5 is usually the main driver during wildfire smoke events, AQI is often a useful indicator. But the speed of change means you need to check right before heading out, not just in the morning.
AQI Thresholds During Smoke Events
During wildfire smoke, be more conservative with AQI thresholds than you would with normal urban pollution. The particle composition is more harmful, and levels can worsen quickly mid-workout.
AQI 0–50 — Clear or Minimal Smoke
Safe for all outdoor exercise. Conditions may change, so check forecasts if fires are active in the region.
AQI 51–100 — Light Smoke / Moderate
Most can train outdoors. Shorten long sessions and avoid peak-effort intervals. If you can smell smoke, consider going indoors.
AQI 101–150 — Moderate Smoke
Move workouts indoors. If you must be outside, keep it short and low-intensity. An N95 mask helps with particles but adds breathing resistance.
AQI 151+ — Heavy Smoke
Do not exercise outdoors. Even walking exposure adds up. Stay indoors with windows closed. Use a HEPA air purifier if available.
Check Your Route's Air Quality
See segment-by-segment AQI along your running or cycling route before heading out.
Try Aeriqo FreeIndoor Alternatives During Smoke Events
Smoke events can last days to weeks. Rather than losing fitness, shift your training indoors. The key is making sure your indoor space actually has clean air.
Indoor Training Options
- Gym with HVAC filtration: Most commercial gyms have filtered air systems. Call ahead during smoke events to confirm they’re running properly.
- Home treadmill or trainer: Close all windows and run a HEPA air purifier if you have one. Even without a purifier, indoor air is much better than outdoor during smoke.
- Indoor pool: Swimming is a great cross-training option. Pool facilities tend to have good ventilation systems.
- Bodyweight and strength work: Use smoke days for strength sessions, yoga, or mobility work. Your lungs get a break, and you address training areas runners often neglect.
If your building has a fresh air intake, check that it’s not pulling in smoky outdoor air. Some HVAC systems can be set to recirculate mode during smoke events.
Ventilation and Recovery
After smoke exposure, your body needs time to recover. Even short outdoor exposure during heavy smoke can irritate airways and trigger inflammation.
Keeping Indoor Air Clean
- • Keep windows and doors closed during smoke events
- • Run a HEPA air purifier in the room where you exercise
- • Set HVAC to recirculate mode if your system supports it
Recovery After Exposure
- • Hydrate well — your airways recover faster when moist
- • Take 1–2 easy days after significant smoke exposure
- • If coughing or tightness persists beyond 48 hours, see a healthcare provider
Many healthy athletes feel noticeably better after a day or two of cleaner air, but recovery time varies. Don’t rush back to intense outdoor training just because the sky looks clearer — check the AQI first.
Frequently Asked Questions
Can I run if I can smell smoke but the AQI says 'Moderate'?
If you can smell smoke, conditions may be worse at your location than the nearest monitoring station shows. AQI stations can be several kilometers away. Use extra caution and consider shortening your workout or moving indoors.
How long does it take for air quality to recover after a wildfire?
It depends on wind patterns and fire activity. Once a fire is contained or winds shift, PM2.5 can improve from hazardous to good within 12–24 hours in favorable conditions. However, secondary fires or wind shifts can bring smoke back just as quickly.
Does an N95 mask help during wildfire smoke?
For PM2.5 particles, yes — when properly fitted. However, at AQI above 150, the particle load is high enough that even with a mask, outdoor exercise is not recommended. Use masks for necessary outdoor time, not for training.
Is it safe to exercise indoors during smoke events?
Generally yes, as long as your indoor space has filtered air or at least closed windows. Indoor PM2.5 is often lower than outdoor levels, especially when windows stay closed. A HEPA purifier can reduce indoor particles further.
Should I worry about long-term effects from a few days of smoke exposure?
Occasional short-term exposure during a smoke event is unlikely to cause lasting harm for healthy individuals. However, repeated exposure over multiple fire seasons may have cumulative effects. The best strategy is to minimize exposure when possible.
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