Which energy pathway is not quickly activated but can supply energy for long periods when oxygen is available?

The energy pathway that is not quickly activated but can supply energy for long periods when oxygen is available is the aerobic pathway. This pathway is essential for endurance activities, such as long-distance running or cycling, where energy needs to be sustained over extended periods.

In aerobic metabolism, the body utilizes oxygen to convert carbohydrates and fats into energy, allowing for more prolonged activity than anaerobic pathways, which primarily generate energy quickly but for shorter durations. While creatine phosphate provides immediate energy for short bursts of high-intensity exercise, it does not sustain long-term energy needs. ATP is the basic energy currency that cells use, but it is rapidly consumed and regenerated rather than being a pathway itself.

The aerobic pathway supports activities that require sustained output, providing energy as long as oxygen is present, making it crucial for prolonged athletic performance and general fitness.