I think here is a mistake.

[Dr. Arch]

Linguist here. That "throw" is in the bare infinitive. Only one verb per clause may have tense assigned to it, and for this clause, the main verb is "do," which is in the simple present. "Like throw..." is an adjunct phrase and does not have tense. As such, "throw" does not have tense.

You can further test this observation by translating the sentence to a more morphologically complex language, like Spanish.

The sentence reads: "Atletas pesados hacen cosas como tirar piedras grandes..." "Tirar" (throw) is in the morphological infinitive.