POWERbreathe Classic Inspiratory Muscle Trainers were created following the realisation that breathing not only presents a limitation to exercise tolerance in patients with respiratory illness, but also limits healthy people, including athletes. Leading Sports Scientists at Loughborough & Birmingham Universities discovered that the inspiratory muscles respond to training in the same way as other muscles – when muscles are overloaded regularly for a period of a few weeks, they adapt, increasing their strength, power & endurance. In 2001, following intense research, trials & development programmes by this team of Sports Scientists at Britain’s leading Human Performance Research universities, the POWERbreathe Classic series was launched. The POWERbreathe Classic series applies the principles of resistance training (pressure threshold training using a load calibrated spring) to strengthen the breathing muscles by making them work harder, in much the same way as you might use weights to increase the strength of your arm muscles. The POWERbreathe Classic series features 9 manually adjustable training levels to allow for progressive training.