Afterburning refers to two distinct phenomena in different fields. In aerospace engineering, afterburning describes the use of an afterburner in jet engines to produce additional thrust. This involves injecting fuel into the hot exhaust stream after it leaves the turbine. The fuel ignites in the exhaust, increasing temperature and velocity of the exhaust gas, which raises thrust. Afterburners are common on many military fighter aircraft and some high-speed interceptors and research aircraft. They provide a temporary, large thrust boost for takeoff, rapid climb, or supersonic acceleration, but at a substantial cost in fuel consumption and heat load. The system adds complexity and requires careful control of fuel flow and nozzle geometry; the flame is highly visible and adds heat to the airframe and surrounding environment. In exercise science, afterburning is often used to describe excess post-exercise oxygen consumption (EPOC), the period after physical activity during which metabolism remains elevated. This results from processes such as replenishing energy stores, clearing lactate, and restoring body systems to resting conditions. The magnitude and duration of afterburning depend on exercise intensity, duration, and individual factors. While it contributes to total energy expenditure, estimates vary and it is not a reliable sole method for fat loss; the overall impact is typically smaller than the calories burned during the workout itself.