Figure 6

Respiratory exchange ratio. Changes in respiratory exchange ratio (mean ± standard error) in summer D (●; n = 7), summer non-D (○; n = 8), winter D (■; n = 7), and winter non-D (□; n = 8) groups. ^a′P < 0.1, ^aP < 0.05 compared with summer D (●) and winter D (■). In a post hoc test, respiratory exchange ratio in the haplogroup D was significantly lower in winter than in summer 10 and 20 minutes after the start of exposure and tended to be lower at 0, 30, 40, and 50 minutes ( P < 0.1)