in experiment 1 six healthy volunteers who had been taking either placebo ( group P ) or the ACE inhibitor captopril ( 150 mg/day for 3 days ; group C ) performed a cycle ergometer graded exercise test at four different exercise intensities : stage 1 , half of the intensity at the blood lactate threshold ( WLT ) ; stage 2 , the intensity at WLT ; stage 3 , the intensity at 4 mmol/l blood lactate ; and stage 4 , an intensity between stage 3 and maximum intensity .
