Many athletes and trainees looking to maximize the benefits of their aerobic training program are using “Altitude Masks”. Manufacturers have claimed that the products can: strength the diaphragm, increase lung capacity, increase anaerobic threshold, increase stamina, and improve fitness. Is there evidence to support these claims? If so (or not), what effect (or lack of effect) have these masks been shown to have on lung function, VO2 max, and other performance related physiological parameters? 
Please support your position with peer-reviewed evidence and provide references to any and all studies that you use to support your claim. 

200-300 words 

APA Format 
DUE TUESDAY FEBRUARY 11, 2020