David pelzer was exposed to what kind of child abuse

Physical abuse

Explanation:

He was finally rescued in 1973, when the evidence of starvation and physical abuse -- he was 12 years old but weighed only 68 pounds -- became so obvious that police and social workers acted. The books are hard to read. Pelzer was subjected to sadistic mistreatment for years. He was beaten, starved, burned, stabbed.

which ever one is showing doing the same exercise in time intervals such as 30 seconds or a minute several times.