Hal v. Stice: bodies that don't need to warm up
Hal and Stice didn’t have to stretch and barely warmed up at all, after the run. They’d changed clothes and were both expressionless.
Context
A small index of how conditioned these bodies are: on a cold afternoon, having jogged over from the golf course, Hal and Stice "didn't have to stretch and barely warmed up at all," then went straight into high-caliber tennis, "both expressionless." The machine idles hot; the run was the warm-up. What would seize an ordinary body cold is just the pre-loaded state these two live in.