Compared with placebo , IMT increased maximal inspiratory pressure ( +34 % 43 % , P = 0.008 ) , diaphragm thickness at residual volume ( +38 % 39 % , P = 0.03 ) , and peak inspiratory flow ( +35 % 42 % , P = 0.049 ) but did not change other spirometry measures , plasma cytokine concentrations , DNA damage levels in peripheral blood mononuclear cells , dynamic inspiratory muscle function , inspiratory muscle endurance , exercise performance , PAL , or QoL .