has anyone tried a powerbreathe and do they work?

i have been looking at a mazagine and in thier there was a article regarding powerbreathe its supposed to strengthen your lung muscles therefore making it easier to breathe but they are £50 does anyone know if its worth buying one and do they work thanks in advance hannah

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I had the medical one as theres three different types, i found it really hard and on discusssion with my fab cons he told me it wouldnt work coz my asthma severe and because i have probs with my breathing muscles aswell.it strenghens your inspiritory muscles but not you expiritory, So check with your doc first and if ok you can have mine.

Andrea xx