Fig. 1. The time to exhaustion (endurance) is plotted for the percentages of o_2max at which the subjects exercised. The data are combinations of the data from selected studies cited in Table 1. The circles represent exercise time for subjects eating a "normal endurance runners diet" consisting of high CHO (60%), but too few calories to meet energy expenditures (25% less than expended). The squares represent subjects who ate an isocaloric diet high in CHOs. The triangles represent data for subjects on an isocaloric diet that consisted of 30% to 65% fat and at least 30% CHOs. The lines through the data were fit by the least squares method. The data for the three diets are significantly different from each other.