There is concern that wearing a face mask during COVID will affect oxygen uptake, especially during intense exercise. This study will assess the effect of wearing two different face masks (disposable and cloth) on blood and muscle oxygenation during cycling exercise.

There is concern that wearing a face mask during exercise will reduce oxygen uptake or increase carbon dioxide re-breathing, which can result in low blood oxygen levels, reduced oxygen delivery to muscle and reduced exercise capacity. The purpose of the study is to determine the effect of wearing two different types of commonly-worn face masks (diposable and cloth) during exercise on blood and muscle oxygenation. Twelve participants who are experienced with cycling will take part in this randomized cross-over study that will assess blood oxygenation (i.e. pulse oximetry) and muscle oxygenation (with near infrared spectroscopy) during a progressive step exercise test to exhaustion. The conditions include no mask, a disposable mask, and a cloth mask. Outcome variables include exercise duration, rating of perceived exertion, blood oxygen saturation levels, and oxygenated, deoxygenated, and total hemoglobin at the quadriceps muscle.

Inclusion Criteria:

• Experienced with cycling

Exclusion Criteria:

• Contra-indications to exercise as identified by a screening questionnaire (the "Get Active Questionnaire")

The individual who will statistically analyze the data will be blinded to condition