< Back to Article

Metabolic Factors Limiting Performance in Marathon Runners

Figure 1

Relative use of fat and carbohydrate as metabolic fuels depends on exercise intensity.

Fractional usage of carbohydrate (plasma glucose plus muscle glycogen, blue filled curve, ) and fat (plasma free fatty acids plus muscle triglycerides, red filled curve, ) are shown as functions of relative exercise intensity, . (Based on the work of Romijn and colleagues: Points plotted correspond to data points from the 1993 study [24], and corresponding error bars are computed as described in the Methods section.)

Figure 1