Mask Wearing in the Gym. ππ½ββοΈ If youβre used to blasting away on the treadmill at a 5.0 speed and at least that much of an incline, you might need to re-think your work-out when you return to the gym. The best advice is to begin at a lower level and slowly increase exertion. πββοΈπππΎββοΈ