Figure 3: Changes in respiratory and circulatory parameters and acetone excretion (VAcetone) during 20 minutes submaximal-intensity exercise experiment (SEE). Note: Before exposure to the experimental gas, subjects inhaled ambient room air for 10 minutes during seated rest to establish a baseline. VO2: oxygen uptake; VCO2: carbon dioxide output; VE: minute ventilation; HR: heart rate. Data are expressed as mean ± SE. *P < 0.05, vs. baseline; †P < 0.05, vs. control trial (two-way repeated measures analysis of variance followed by Bonferroni’s multiple comparisons). Some error bars are smaller than the symbols.