Answer: all of these exercise modes, but less likely with low intensity endurance training.
Explanation: exercise increases respiration requirement and therefore oxygen requirement. Energy stores (glycogen) are used first but with then the body needs to maintain energy production at an increased level. There is a limit to how quickly energy can be supplied from respiration and additional energy is generated anaerobically with the by product being lactic acid. An ‘oxygen debt’ is incurred because normal homeostasis requires the metabolism of lactic acid and energy for repair of any cellular damage, requiring oxygen consumption above what is required for normal resting metabolism. It is possible in elite athletes that during low intensity training they may be able to operate aerobically for an extended period.