With incremental exercise, cardiopulmonary parameters at peak exercise before and after 3-week administration of ghrelin or placebo with PR. Solid symbols, ghrelin; Open symbols, placebo. Data are presented as means ± SD. * p < 0.05, ** p < 0.01: change between pre-treatment and post-treatment (between ghrelin and placebo group difference, treatment effect) by unpaired t-test: † p < 0.05, †† p < 0.01: repeated-measures ANOVA indicates significant time-course effects of ghrelin versus placebo. , oxygen uptake; VD/VT, physiologic dead space/tidal volume ratio, , minute ventilation; VT, tidal volume.