On this page
The cheetah's body is built to be fast, but not for long. Here is what each adaptation does, the numbers behind it, and how to turn them into a full-marks answer.
What body adaptations make a cheetah so fast?
Flexible spine. A cheetah's spine works as a spring for its powerful back legs, extending its reach with each step (Smithsonian's National Zoo). A 2011 study comparing cheetahs with racing greyhounds proposed that the cheetah powers acceleration using its extensive back muscles (Hudson et al., Journal of Anatomy).
Long legs. The same study found the cheetah's hindlimb bones were proportionally longer and heavier than a greyhound's, letting it take longer strides and potentially resist higher peak forces on the limbs (Hudson et al.).
Large nasal passages. Large nostrils and lungs give quick air intake, so the cheetah can breathe more easily while running (Smithsonian's National Zoo). Its large nasal cavities also help it gulp in air to recover after a chase (National Geographic).
Claws that stay partly out. Special paw pads and semi-retractable claws give the cheetah great traction (Smithsonian's National Zoo). Claws that stay partly out work a little like a sprinter's spikes; our explainer on why sprinters wear spiked running shoes covers the friction physics.
Tail as a rudder. The tail acts as a rudder for quick turns, counteracting the body's weight (Smithsonian's National Zoo).
How fast can a cheetah run, and how do we know?
In a study published in 2013, Alan Wilson and colleagues fitted five wild cheetahs in Botswana with collars carrying GPS and motion sensors and recorded 367 runs, most of them hunts (Wilson et al., Nature). The top speed recorded was 25.9 m/s, or 93 km/h, but most hunts involved only moderate speeds (Wilson et al., Nature). The team also recorded some of the highest acceleration, deceleration and power per kilogram measured in any land mammal.
Can you check a cheetah's speed with kinematics?
The National Zoo gives two figures you can test with Class 9 kinematics: at top speed a cheetah covers about 7 m per stride and completes four strides per second, and it can go from 0 to 72 km/h in 2.5 seconds (Smithsonian's National Zoo).
Speed = stride length × stride frequency = 7 m × 4 per s = 28 m/s.
Convert: 28 × 3.6 = about 101 km/h, inside the zoo's quoted range of 96 to 112 km/h.
Acceleration: 72 km/h ÷ 3.6 = 20 m/s, so average a = 20 ÷ 2.5 = 8 m/s², a little under g (9.8 m/s²).
Distance in that time, if the acceleration were steady: s = ½at² = ½ × 8 × 2.5² = 25 m.
Longer strides raise speed directly in step 1. If questions like this trip you up, the Fermi Problem Library has worked problems with a step-by-step solver that explains the reasoning rather than printing an answer.
Why does a cheetah get tired after a short sprint?
Full sprints last about 20 seconds, and the zoo describes the movement as physiologically taxing (Smithsonian's National Zoo). Real hunts typically cover less than 300 m (Hetem et al., Biology Letters).
For decades the textbook reason was overheating. A 1973 treadmill study by Taylor and Rowntree concluded that running cheetahs stored metabolic heat until further exercise became impossible at a rectal temperature of 40.5°C (as summarised by Hetem et al.). But those cheetahs ran at no more than 30 km/h, far from a real chase.
In 2013, Robyn Hetem and colleagues logged body temperature in four free-living cheetahs as they hunted (Hetem et al., Biology Letters). Body temperature averaged 38.4°C when a chase ended, so the cheetahs were not quitting because they overheated. Temperature rose more after a successful hunt (1.3°C) than an unsuccessful one (0.5°C), which the authors proposed was stress rather than exercise.
So the honest exam answer: the sprint is a short, all-out burst the body cannot keep up for long, and the cheetah then needs to recover its breath, which is where the large nasal passages help. Field data has challenged the overheating story. Our post on how muscles tire with repeated work has a simple experiment you can try on yourself.
How do you write a cheetah adaptation answer in an exam?
Use a three-part line for each feature: structure, function, link to speed.
Flexible spine: bends and straightens like a spring; lengthens each stride; more distance per stride means more speed.
Long hindlimbs: longer bones; longer stride; speed = stride length × frequency.
Large nasal passages: quick air intake; breathing during and after the sprint; faster recovery.
Semi-retractable claws: stay partly out; grip the ground; better acceleration, braking and turning.
Tail: acts as a rudder; counterbalance; quick turns.
For a five-mark answer, pick four features, then add one line on the limit: full sprints last only about 20 seconds (Smithsonian's National Zoo). For contrast, see how earthworms, snails and birds move. If locomotion or respiration still feels shaky, the Fermi Concept Library gives each concept its own lesson.
