Have you ever noticed an unpleasant smell at your gym? That could be a sign of something more concerning: poor air quality. While going to gyms makes you healthier, the air inside may not be as clean as we think. So, how bad is the air you breathe during your workout? Let’s take a closer look.
How Are the PM2.5 and PM10 Levels in Gyms?
A study in Portugal reveals that gym air quality is often compromised by poor ventilation, cleaning detergents, and the resuspension of dust and particles due to high activity levels.
The study found that PM2.5 levels in gyms ranged from 5.8 to 35.9 µg/m³, with an average of 21.5 µg/m³, while PM10 ranged from 8.6 to 48.8 µg/m³, with an average of 31.2 µg/m³.
These numbers are quite concerning compared to the WHO guidelines, which recommend that PM2.5 should not exceed 15 µg/m³ for 24 hours and that PM10 should stay below 45 µg/m³ over the same timeframe. In many gyms, PM2.5 levels exceeded this limit and doubled during peak hours.
| Pollutant | Average Measured Concentration | WHO 24-Hour Safe Limit | %Exceedance of Safe Limit |
| PM2.5 (µg/m³) | 21.5 | 15 | 43.3% |
| PM10 (µg/m³) | 31.2 | 35 | 0.00% |
Read more: Particle Air Pollution: PM10 vs PM2.5
Are CO2 Levels High in Gyms?
CO2 levels indicate how well a space is ventilated. High CO2 concentrations in gyms can indicate poor ventilation.
The study found that average CO2 levels in gyms are around 1,489 mg/m³. This is 1.5 times above the recommended levels by ASHRAE, ideally staying below 1,000 mg/m³ to ensure good air quality.
This suggests that many gyms struggle to maintain adequate ventilation during peak times, leading to a buildup of pollutants.
How About the TVOC levels in Gyms?
At gyms, TVOC levels range from 0.27 mg/m³ in HC2 to 3.80 mg/m³ in HC3, but the average is 2.34 mg/m³, which exceeded WHO safe limit of 1 mg/m³, with 69% of the indoor spaces above this limit.
The study identified that gym VOC levels could spike, particularly after cleaning activities or during peak hours when more people use the facilities.
Should I Avoid Going to the Gym During Peak Hours?
Yes, good idea. Both PM25, PM10, TVOC, and CO2 levels were significantly higher during busy times exceeding the WHO-recommended limits. When gyms become crowded during peak hours, it causes more resuspended particles and CO2 emissions, which increases the overall pollution load in the indoor environment.
If you have respiratory issues or are particularly sensitive to poor air quality, exercising in the gym during off-peak hours when fewer people are present can reduce your exposure to harmful pollutants.
Is It OK to Workout in a Gym With Poor Air Quality?
The WHO recommends that indoor PM2.5 levels should stay below 15 µg/m³; however, many gyms in the study reported average levels that exceeded this limit, with some peaking at nearly 36 µg/m³. PM2.5 can penetrate deep into the lungs and increase the risk of cardiovascular and respiratory diseases, especially during intense exercise.
If a gym’s air quality consistently exceeds these limits, working out there is certainly not ideal. You might consider exercising outdoors when the air quality is within safe limits, or you may want to switch to a different gym. Bring your air quality monitor to test the air there!
Pollutant Concentrations in 8 Gyms in Portugal and Safe Limit Exceedance
| Pollutant | Average Measured Concentration | 24-Hour Safe Limit | % Exceedance of Safe Limit |
| PM2.5 (µg/m³) | 21.5 | 15 (WHO safe limit) | 43.3% |
| PM10 (µg/m³) | 31.2 | 35 (WHO safe limit) | 0.00% |
| TVOC (mg/m³) | 2.34 | 1 (WHO safe limit) | 134% |
| CO₂ (mg/m³) | 1,489 | 1000 (ASHRAE) | 48.9% |
What Are the Solutions Here?
1. Choose a gym with an air purification system in place
When selecting a gym, opt for one that uses air purification systems, such as those with HEPA filters. Air purifiers with HEPA filters can remove 99.5% of harmful particles and improve air quality.
2. Build your home gym with air purifiers
If air quality is a consistent concern at your local gym, setting up a home gym could be a solution. Make sure to install air purifiers with HEPA filters to maintain clean air during your workouts.
3. Increase ventilation
Gym owners can improve air quality by enhancing ventilation systems. Increasing air changes per hour by opening windows and adjusting their HVAC systems can help dilute pollutant levels.
4. Try an outdoor gym when the air quality is within the safe limit.
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