Seconds are pretty long. Even a jogger takes something like 170-200 steps per minute. I think if you go out and try to have fast turnover you can probably approach ~300 steps per minute, and humans don't have fast strides compared to a lot of animals. That the fastest land animal can do a little over twice that turnover is kind of underwhelming if anything.. I'd be surprised if there aren't tons of other land animals that have similar turnover -- even animals that aren't really that fast in absolute terms like squirrels probably have very fast steps.