Yeah in retrospect, adding some sort of stamina/energy would have probably been a good idea.
I'm hoping to expand on this idea in a game project I'm working on right now, so stay tuned! :D
Something to note is I didn't make the animations, just the model. I found the animations on this site called Mixamo, and I just did the work of binding them to input so that it feels nice and snappy and transitioning between them.