I am allergic to pollen and at the moment I feel that I have a little more difficulty breathing than usual. I did a desensitization, it worked at 95% but there is still this little "asthma" that I already have naturally that is amplified (I have trouble exhaling but my inspiration is good).
Anyway, I'd like to tone my breathing muscles. I read a recently written article that praises the breathing masks that simulate altitude. Apparently it tones these muscles well, improves the quality of the arteries, increases life expectancy a little.
I checked with Intersport and Decathlon, they don't sell them. I didn't try GoSport but here it would be a 9€ thing, worthless.
Which mask would you recommend? I have no budget limit. I think there's the Phantom, but is it a good one?