Why midsize animals are the fastest
New simulation suggests that speed has body mass limits
![cheetah and wildebeests](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2017/08/081917_scivis_main_NEW.jpg?fit=860%2C460&ssl=1)
FULL SPEED AHEAD The speed demons of the animal kingdom are hardly giants. A new study suggests larger animals run out of fuel for their muscles before reaching top speeds.
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