Personal strategies to mitigate the effects of air pollution exposure during sport and exercise
A narrative review and position statement by the Canadian Academy of Sport and Exercise Medicine and the Canadian Society for Exercise Physiology
Andy Hung1, Sarah Koch2,3,4, Valérie Bougault5, Cameron M Gee6,7, Rômulo Bertuzzi8, Malindi Elmore7, Paddy McCluskey7,9, Laura Hidalgo López2,3,4, Judith Garcia-Aymerich2,3,4, Michael S Koehle1, 9,10
Air pollution is among the leading environmental threats to health around the world today, particularly in the context of sport and exercise. With the effects of air pollution, pollution episodes (e.g., wildfire conflagrations), and climate change becoming increasingly apparent to the general population, so has its impact on sport and exercise.
As such, there has been growing interest in the sporting community (i.e., athletes, coaches, and sports science and medicine team members) in practical personal-level actions to reduce the exposure to and risk of air pollution. Limited evidence suggests the following strategies may be employed:
- minimizing all exposures by time and distance;
- monitoring air pollution conditions for locations of interest;
- limiting outdoor exercise;
- using acclimation protocols;
- wearing N95 face masks; and
- using antioxidant supplementation.
The overarching purpose of this position statement by the Canadian Academy of Sport and Exercise Medicine and the Canadian Society for Exercise Physiology is to detail the current state of evidence and provide recommendations on implementing these personal strategies in preventing and mitigating the adverse health and performance effects of air pollution exposure during exercise, while recognizing the limited evidence base.
Protective Strategies for Exercise & Physical Activity in Air Pollution
Before/After Training & Competition
Monitoring of pollution levels
- Use websites and phone applications that report and predict local pollution levels for specific sites and hours using specific air pollution levels and quality indices such as the Canadian Air Quality Health Index (AQHI).
Pre-exercise/competition & face masks
- AVOID: Increased pollution exposures, during transport to venue.
- CONSIDER: (i) Wearing face masks outside of training and competition when local air pollution levels are high.
(ii) close vehicle windows, turn on air conditioning, use cabin air filters.
- Current evidence does not suggest that asthma medications aggravate acute effects of air pollution during exercise. Patients with asthma or exerciseinduced bronchoconstriction should use medications as prescribed.
- Beta-carotene, 100g vitamin E, and 500g vitamin C, at least one week prior to competition might reduce reductions in respiratory function due to ozone exposure.
Exposure reduction by time
- AVOID: (i) seasonal exposures (e.g. wild fires).
(ii) peak ozone levels in the afternoon and evening.
- CONSIDER: Exercise during mornings, participate in events when local seasonal events (e.g. wild fires) are less likely
- Repeated exposures to ozone in the days before competition might preserve respiratory function, reduce respiratory symptoms, and mitigate performance declines.*
* More research on acclimation to air pollution is needed
During Training & Competition
- Exercise intensity does not appear to potentiate adverse effects of pollution but evidence is scarce. In periods of high traffic- related air pollution exposure or ozone, a reduction in the total inhaled dose (concentration x ventilation x time) is more important than avoiding high intensity exercise.
- PAY ATTENTION TO: Type of indoor air filtration, ventilation practises (e.g. windows open/closed, room size & occupancy).
- ICE AND SNOW: Type of air resurfacing and snow machines, snow snowboard/ski wax.
- FITNESS CENTRE: Type and frequency of disinfectants, cleaning agents, fresheners and candles.
Exposure reduction by distance
- AVOID: Major traffic arteries, large construction sites, dense built environments (e.g. high-rises, road network).
- CONSIDER: Choose routes along smaller, open streets, through parks, green and blue spaces.