When endurance athletes push themselves to exhaustion, their jumping ability gets worse in normal or low-oxygen air, but stays the same in hot conditions. This shows that different types of tiredness affect muscles differently depending on the environment.

Breathing less oxygen while exercising hard makes endurance athletes tire out faster because it weakens their muscles' ability to work properly, but getting hot doesn't really change how their muscles perform.

When people who regularly lift weights push their muscles until they can't do any more reps, their ability to jump high drops more right after than if they stopped before getting tired. This means their muscles and nerves are more worn out.