Figure 2. Comparison of heart rate [HR] response between the 2 laps of the ultramarathon. HRlte = long-term endurance HR (<119 b.min-1);

HRea = extensive aerobic HR (= 119-145 b.min-1);HRia = intense aerobic HR (= 145-171 b.min-1); HRhi = high-intensity HR (>171 b. min-1)