Training and racing in a fresh indoor air environment is vital to our health and performance. Is the air in your Gain Cave causing you more harm than good?
We wear it on our jersey sleeves like a badge of honor. A symbol of our ‘No Pain Cave, No Gain’ cycling mentality. Proof of our ability to withstand abnormal amounts of discomfort with a smile by doing so in a place where even sunlight fears to dwell. But poor indoor air quality may be lurking in the shadows.
Where the walls sweat as much as we do and the air is so thick it can stop a stationary bike, your subterranean suffering studio makes you thankful for your evolutionary gift of nose blindness.
Judging the quality of our workouts by how uncomfortable we feel during and afterward may not be the healthiest habit, however. Scaling strewn debris and hurdling heaps of soiled chamois is a good warm-up, but breathing in excessive amounts of polluted and contaminated indoor air is a serious health risk.

Asthma is the Most Common Chronic Condition in Athletes
The prevalence of asthma and exercise-induced breathing disorders is markedly increased in elite athletes. The authors of a 2012 study cited asthma as the most common chronic medical condition experienced by both Summer and Winter Olympic athletes.
The researchers of a study published in the British Journal of Sports Medicine suggest that the lining of the airways is damaged during exercise. The damage occurs in competitive athletes performing high-level training, mainly when the exercise is performed in extreme environmental conditions such as cold and polluted air.
High-Intensity Exercise Damages the Lining of Our Airways
The cells which line our airways act as a physical barrier against environmental toxins, therefore maintenance of their integrity is vital. When this barrier is damaged, there is a greater potential for infection by bacteria and viruses, and penetration by pollutants and irritants.
The rapid and deep breathing that occurs during intense aerobic exercise causes significant dehydration and cooling of the lining of our airways, causing dehydration stress. There is also a more significant amount of mechanical shear and stretch forces from rapid and deep breathing during high-level exercise that damages the airways.
The repeated injury and repair process of the airway lining leads to changes within the airways and is an underlying cause of asthma.
Indoor Air Can be More Dangerous than Outdoor Air
According to an article published in the journal Science of the Total Environment, the air within our homes can be more seriously polluted than the outdoor air. In addition, people spend approximately 90 percent of their time indoors and are at risk for “Sick Building Syndrome.”
For the virtual cyclist, the health risks are magnified by the exposure to indoor pollutants while engaging in high-level exercise.
The Causes of Indoor Air Problems
Indoor pollution sources that release gases or particles into the air are the primary causes.
Combustion sources of indoor air pollution include:
- Home heating and cooking devices that utilize oil, gas, kerosene, coal, and wood for fuel.
- Tobacco products.
- Central heating and cooling systems.

Carbon monoxide (CO) is a colorless, odorless gas that interferes with oxygen delivery to our body and can be fatal if not recognized in time.
Inadequate ventilation causes increased concentrations of pollutants and prevents indoor air pollutants from leaving your home. Most homes are air-tight by design, and unless they are built with additional mechanical means of ventilation, pollutants accumulate.
Biological contaminants of indoor air include:
- Molds
- Mildew
- Animal Dander
- House Dust Mites
- Pollen
Identifying Air-Quality Problems
- Develop symptoms of respiratory illness - Health effects can be valuable indicators if they appear to occur after an environmental change or linked to an activity or location within your home.
Notify a health professional immediately if you suspect environmental exposure.

- Detecting potential sources - Be aware of the type and number of potential sources in your home.
- Lifestyle and activities - Our habits and behaviors are significant sources of indoor pollution.
- Detecting ventilation issues - Signs that indicate your home has poor ventilation include moisture condensation on windows or walls, smelly or stuffy air, dirty central heating and air cooling equipment, and areas where books, shoes, or other items become moldy.
- Air-Quality Detector - There are air-quality detectors intended for home use that can be valuable in the identification of problems.
I tried out a few of the air-quality detectors on the market intended for home use. I chose the one which I felt best suited my needs and that of my fellow virtual cyclists for the mini-experiment I conducted in my ‘Gain Cave.’ The will share the interesting results in Part Two.
To detect air quality issues in your home, step outside for a few minutes, and then upon reentering your home, note whether odors or a feeling of stuffiness are noticeable.
The Basic Steps to Control Indoor Air-Quality Problems
- Source Control - The most effective way to improve indoor air quality is to identify and eliminate or reduce the source.
- Ventilation Improvements - Increasing the amount of outdoor air coming into your home will lower the concentration of indoor air pollutants.

Opening windows and doors, operating window or attic fans, or running your window air conditioner with the vent control open increases the outdoor ventilation rate.
- Air Purifiers - The utilization of a quality air cleaning device and frequent replacement of the heating and air conditioning filters in your home will decrease the number of indoor pollutants.
- Humidity Level Control - The growth of some sources of biologicals, like mold and mildew, can be minimized by maintaining your home and exercise area at a relative humidity of 30-50 percent.
- Air Duct Maintenance - Contaminated ducts and central air conditioning units provide an environment for the growth of molds, mildew, and other pollutants and efficiently spread them throughout your home.
Steps to Control Basement Exercise Area Air-Quality Problems
- Frequent and thorough cleaning and disinfecting of all surfaces.
- Clean and disinfect basement floor drain regularly.
- Repair foundation water leaks.
- Provide adequate outdoor ventilation and heat to prevent condensation.
- Operate a dehumidifier to keep the relative humidity level between 30-50 percent.
- Do not store household cleaning supplies, pesticides, or other chemicals, unless kept in an air-tight container.
- Avoid exercising near a functioning heating unit or laundry appliances.
- Carpeting is a poor choice for basement floor covering due to its predisposition to hold moisture and become a breeding gound for biological contaminants.
- Be aware of the presence of asbestos and lead-based paints in older homes and buildings.
Conclusion
The careful maintenance of our virtual cycling environment is not only essential to our respiratory health but has a significant impact on performance as well.
A cool (not freezing), dry, and well-ventilated training environment promotes evaporative cooling and decreases the performance-limiting effects of even small increases in body temperature.
In addition, repetitive damage to our airways and a higher incidence of infection and illness are never good for training progress.
In the Second Installment of this series, I will bring you the results of a mini-experiment I conducted in my ‘Gain Cave.’ The air quality results will surprise and shock you!
Your Input is Essential
Do you have any tips to improve the indoor air in your cycling studio? Your fellow virtual cyclists could use all the help they can get.
Bibliography
Fitch KD An overview of asthma and airway hyper-responsiveness in Olympic athletes British Journal of Sports Medicine 2012;46:413-416.
Kippelen P, Fitch KD, Anderson SD, et al. Respiratory health of elite athletes – preventing airway injury: a critical review, British Journal of Sports Medicine 2012;46:471-476.
“The Inside Story: A Guide to Indoor Air Quality – EPA – US EPA.” 22 Oct. 2020, https://www.epa.gov/indoor-air-quality-iaq/inside-story-guide-indoor-air-quality. Accessed 15 Jun. 2021.
Semi-retired as owner and director of his private Orthopedic Physical Therapy practice after over 20 years, Chris is blessed with the freedom to pursue his passion for virtual cycling and writing. On a continual quest to give back to his bike for all the rewarding experiences and relationships it has provided him, he created a non-profit. Chris is committed to helping others with his bike through its work and the pages of his site.
In the summer of 2022, he rode 3,900 miles from San Francisco to New York to support the charity he founded, TheDIRTDadFund. His “Gain Cave” resides on the North Fork of Long Island, where he lives with his beautiful wife and is proud of his two independent children.
You will read him promoting his passion on the pages of Cycling Weekly, Cycling News, road.cc, Zwift Insider, Endurance.biz, and Bicycling. Chris is co-host of The Virtual Velo Podcast, too!
[…] researching Part One of this article series, it was clear I couldn’t deny it any longer. I had to find out for […]
Very interesting! Thnx for sharing
Thank you, Jan! Read Part 2 if you have a moment. It will make you think.