Why indoor workouts during high AQI might possess risks to your health |

High pollution levels have become a familiar part of daily life in many Indian cities, and you may feel tempted to retreat indoors whenever the AQI surges. The assumption that indoor exercise automatically protects you from harmful air, however, does not always hold true. Gyms, fitness studios, and even home workout rooms often struggle to maintain clean air when outdoor pollution is severe, especially if ventilation is limited or air filtration is inconsistent. During training, your breathing rate increases naturally, drawing more air into your lungs with each minute of effort. If that air contains fine particulates, chemical residues, or dust stirred up from surfaces, the effects can accumulate quickly. Understanding how high indoor AQI interacts with physical exertion allows you to make informed choices about safeguarding your respiratory and cardiovascular health while still keeping your fitness routine consistent.

A study referenced by AQI India reports that indoor particulate levels in gyms often rise significantly during high pollution days because commercial ventilation systems recirculate contaminated air instead of fully purifying it. When combined with the constant movement of people, equipment, and airflow from fans, pollutants remain suspended for longer periods. As you begin exercising, the deeper inhalation required for oxygen delivery means more pollutants reach sensitive lung tissue, which changes how efficiently your body performs during exertion.Effects include:• Reduced stamina during activities such as running, cycling, or resistance circuits• Airway discomfort or irritation appearing earlier in the workout• Increased fatigue due to diminished oxygen utilisation• Extra cardiovascular strain during prolonged or high intensity sessions

Particulate matter, especially PM2.5, behaves differently indoors compared with open spaces. In enclosed environments, these particles linger because they do not disperse easily without strong ventilation or high grade filtration. When you are training, your respiratory muscles work harder, pulling more air into the lungs than you would during normal daily activities. As a result, fine particles can reach lower airways and trigger physical reactions that disrupt your rhythm and overall comfort. Even individuals with no underlying respiratory conditions may notice subtle signs of irritation, while those with asthma or allergies can experience more pronounced symptoms.Common symptoms include:• A feeling of tightness in the chest during steady exercises• Persistent dry throat or hoarseness shortly after starting• Wheezing or mild coughing during or after the session• Slower recovery between bursts of activity

Polluted air does not only affect the lungs. Pollutants that enter the bloodstream can alter vascular responses, making the heart work harder to maintain the oxygen supply required during exercise. When the AQI outside is high and ventilation indoors is compromised, the additional cardiovascular load becomes noticeable. What would usually feel like a manageable workout may suddenly feel disproportionately intense, even if you maintain the same pace, weight, or duration. Over time, repeated exposure during training can leave you feeling unusually drained.Common symptoms include:• Unexpected heaviness in the legs during warm up• Sharp spikes in heart rate even with moderate activity• Light headedness or slight dizziness after finishing sets• Difficulty sustaining usual endurance levels

Gym environments contain several internal sources of pollution, particularly during busy hours. Cleaning products, disinfectant sprays, synthetic flooring, rubber mats, foam blocks, and high friction equipment release volatile compounds into the air. When outdoor AQI is already high, these internal emissions mix with incoming pollutants and create a dense chemical blend that irritates sensitive tissues in the respiratory tract. While these chemicals may not be obvious at first, deeper breathing during exercise increases their impact because they reach further into nasal and bronchial passages.Common symptoms include:• Subtle burning or stinging sensations in the nose or eyes• Sensitivity to strong cleaning or plastic like smells• Persistent throat discomfort throughout the workout• Longer breathing recovery time between repeated movements

Training in polluted indoor air influences post workout recovery as well. When your body processes pollutants taken in during exercise, it activates inflammatory and stress responses. These physiological processes divert energy that would normally support muscle repair and metabolic regulation. As a result, even a routine session may leave you feeling unusually drained. The effects can extend beyond the workout, influencing how you feel later in the day or the next morning, and reducing consistency in your training schedule if exposure continues over several days.Common symptoms include:• Persistent heaviness or sluggishness after exercising• Stiffness or soreness that appears faster than usual• Delayed heart rate normalisation after cardio• Difficulty maintaining weekly workout intensity

Although high AQI makes indoor training more challenging, you can take practical steps to minimise the health impact while maintaining an active routine. Thoughtful adjustments to timing, space, and workout style help you protect your lungs and cardiovascular system during severe pollution episodes.Practical steps include:• Monitor indoor AQI with a portable device before beginning your workout• Opt for low intensity routines when pollution levels remain high outside• Use an air purifier equipped with a HEPA filter in the workout area• Train during hours when outdoor AQI is relatively lower• Avoid older mats or friction heavy equipment that release chemical smells• Keep windows closed during peak pollution and ventilate only when levels drop• Choose stretching, yoga, or mobility sessions if breathing feels strained• Increase water intake to support respiratory comfort• Take breaks whenever you notice breathlessness or discomfort• Skip workouts temporarily if indoor air remains persistently poorDisclaimer: This article is for general informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider regarding any medical condition or lifestyle change.Also Read | When is the right time to brush your teeth: Before breakfast or after? Know what experts recommend