prey, followed by slowing down as it closes in on it, the deceleration varying by the prey in question. The peak acceleration observed was , while the peak deceleration value was . Speed and acceleration values for a hunting cheetah may be different from those for a non-hunter because while engaged in the chase, the cheetah is more likely to be twisting and turning and may be running through vegetation. The speeds attained by the cheetah may be only slightly greater than those achieved by the pronghorn at and the springbok at , but the cheetah additionally has an exceptional acceleration. One stride of a galloping cheetah measures ; the stride length and the number of jumps increases with speed. During more than half the duration of the sprint, the cheetah has all four limbs in the air, increasing the stride length. Running cheetahs can retain up to 90% of the heat generated during the chase. A 1973 study suggested the length of the sprint is limited by excessive build-up of body heat when the body temperature reaches . However, a 2013 study recorded the average temperature of cheetahs after hunts to be , suggesting high temperatures need not cause hunts to be abandoned. The running speed of of the cheetah was obtained as an result of a single run of one individual by dividing the distance traveled for time spent. The run lasted 2.25 seconds and was supposed to have been long, but was later found to have been long. It was therefore discredited for a faulty method of measurement. Cheetahs have subsequently been measured at running at a speed of as an average of three runs including in opposite direction, for a single individual, over a marked course, even starting the run behind the start line, starting the run already running on the course. Again dividing the distance by time, but this time to determine the maximum sustained speed, completing the runs in an average time of 7 seconds. Being a more accurate method of measurement, this test was made in 1965 but published in 1997. Subsequently with GPS-IMU collars, running speed was measured for wild cheetahs during hunts with turns and maneuvers, and the maximum speed recorded was sustained for 1–2 seconds. The speed was obtained by dividing the length by the time between footfalls of a stride. There are indirect ways to realize how fast are