By Dr. Becker
An interesting study1 was published recently exploring the reasons cheetahs run so much faster than greyhounds, since they share very similar running styles and gross morphology (form and structure).
The cheetah has been clocked at top speeds of about 65 miles per hour. Quarter horses can gallop at up to 47 miles per hour, and humans’ top speed is less than 28 miles per hour. Greyhounds, as speedy as they are, don’t get past the 40 mph mark.
Why Cheetahs and Greyhounds?
Both the cheetah and greyhound use a rotary gallop when they run. Their legs move in a circular motion, their backs bow, and their hind legs stretch forward almost to the ears at full stride. “The cheetah’s back functions as an extension of its hind legs,” Dr. Alan Wilson of the Royal Veterinary College, one of the researchers, points out. The spine coils and extends with each stride (a feat the human body isn’t built to achieve).
The two animals run very similarly up to about 40 miles per hour. So what is it about the wild cheetah that gives him the ability to run another 25 mph faster?
There are inherent difficulties in trying to monitor cheetahs in the wild (especially while they’re running), so researchers studied captive cheetahs in England and South Africa instead.
The cheetahs and greyhounds were taken to a lab where they chased a meat lure on a track embedded with force plates to chart their strides. High-speed cameras were used to record their movements from different angles.
The researchers first confirmed that captive cheetahs don’t run as fast as their wild counterparts. In fact, they topped out at slightly slower speeds than the fastest greyhounds. (It seems having to bring down prey in order to live is strong motivation to learn to run at top speed.)
But according to Dr. Wilson, when the cheetahs were of a mind to, their speed increased dramatically. They brought their legs around faster and faster and their strides got longer.
At 20 miles per hour, the cheetahs took 2.4 strides per second. At 38 mph, they took 3.2 strides per second. The greyhounds, on the other hand, kept a fairly even stride of around 3.5 strides per second throughout their time on the track.
Dr. Wilson suspects wild cheetahs may be able to reach 4 strides per second, which, in combination with longer stride lengths, is what allows them to clock top speeds so much higher than greyhounds.
Another difference noted by the researchers was that the cats’ paws remained on the ground a bit longer than the greyhounds’ paws, an adjustment that helps the legs absorb more of the force of the stride.
In order to attain a high rate of speed, the muscles of the body must be able to withstand the force each time the feet strike the ground. By letting their paws linger on the ground longer than the greyhounds did, the cheetahs’ bodies were able to better absorb the pounding.
According to Dr. Wilson, study results indicate the speed with which the leg is brought back around into position determines how fast an animal can run. The faster the leg can be repositioned, the faster the pace.
Fast leg turnover requires strength, and one area in which cheetahs and greyhounds are built differently is in their upper legs. The cheetah has large upper legs compared to the greyhound, and the cat’s thigh muscles are powerful enough to pump faster than the much smaller legs of the greyhound.
Another thing that helps reposition legs faster is having less weight in the lower portion of the legs.
So if you want to run faster:
- Build up those thighs
- Wear lightweight socks and running shoes
- Run when you’re really, really hungry