Two studies have addressed the variations on FeNO after EIB and they had contradictory results. Scollo et al. found no change in FeNO in either healthy or asthmatic children after a 6-min of vigorous exertion in an exercise laboratory when they studied 24 asthmatic and 18 control children. Terada et al. reported, for 39 subjects, a decrease in FeNO in subjects with EIB and an increase in healthy controls.