Figure 3

Oxygen consumption. Changes in oxygen consumption (mean ± standard error) in summer D (●; n = 7), summer non-D (○; n = 8), winter D (■; n = 7), and winter non-D (□; n = 8) groups. * P < 0.05 compared with summer D (●) and summer non-D (○), ^aP < 0.05, ^a′P < 0.1 compared with summer D (●) and winter D (■), and ^bP < 0.05, ^b′P < 0.1 compared with summer non-D (○) and winter non-D (□). In a post hoc test, haplogroup D oxygen consumption tended to be lower in winter than in summer 20 and 30 minutes after the start of exposure ( P < 0.1). In addition, in summer haplogroup D subjects had significantly lower oxygen consumption than non-D subjects at 80 and 90 minutes ( P < 0.05). Non-D oxygen consumption was significantly lower in winter than in summer 90 minutes after the start of exposure ( P < 0.05)