if i were to wear my ninja mask or something similar during my morning runs would that increase my cardio workout? ive heard of people wearing gas masks and other similar things..
Masks like that are usually for simulating altitude. It helps if you're planning to compete at high terrain by training your body to more easily acclimatize to the lower air pressure. Altitude training has few long-term effects once you return to regular altitude.
If you want to improve your cardio, it may work because it could be some what anaerobic.
But I'd suggest tabata sprints, might be a better exercise for you.
