Why do my hands go weak & toes turn blue sometimes after a long run/workout?

I’ve noticed this off and on – my hands would get weak and stay that way for about 10 to 15 mins after I’m done running or working out. They’d be so weak I’ll have trouble turning the door knob to get back into the house. I also notice sometimes when getting into the shower after a run that my toes feel numb and are blue-ish…

Circulation may be an issue but I’m not sure why they occur only after running/working out.