The runner is a heterotroph because she gets energy from what

She gets the energy from the food that she consumes, the runner can not make her own source of energy like plants do with photosynthesis

The runner gets energy from food and outside sources therefore she is a heterotroph.

Heterotrophs such as humans are not capable of producing their own food by photosynthesis. The heterotrophs rely on other sources such as plants or animal contents for their source of nutrition. The secondary and tertiary consumers are the heterotrophs.

Heterotrophs can further be of two types: organotrophs (obtain hydrogen from organic substrates) and lithotrophs (use inorganic substrates for biosynthesis and energy production).