The study aims to assess the impact of wearing a surgical mask during training on inactive men’s functional capacity and perceived stress. Seventy non-smoker males with body mass index of 25–30 kg/m2 and moderate-intensity activity of fewer than 150 min/week were allocated randomly into two equal groups. The surgical mask group performed a controlled endurance exercise while wearing a surgical mask of three protection layers. The mask-less group performed a controlled endurance exercise without wearing any mask. Functional capacity and Perceived Stress were evaluated before and after the intervention. A significant improvement was observed within groups post-intervention in favor of the mask group regarding the Time Up and Go test (P < 0.05), with a 15.1% percentage improvement. Post-intervention, there was a significant change in the perceived stress score for the mask and mask-less groups (P < 0.05). The improvement in PSS was in favor of mask-less group participants as they changed from being categorized as moderate to mild stress on the PSS, with a 27.1% percentage improvement. Exercising while wearing a surgical mask Positive impacts functional capacity and negatively impacts Perceived Stress in inactive adults. An additional study evaluating the physiological effects of masks on continuous exercise is necessary.