What to do when a strange, aggressive dog sprints toward you?

Say you’re running along and an aggressive dog comes sprinting out from his front yard. If you run faster you may elicit a chase reflex, the same reflex triggered when a dog sees a cat or a squirrel run by. What you should do instead is face the dog and stand still, like a pole or a tree. Your arms can be folded in front of you so that you don’t accidentally swing them around.
Most dogs that race to you even aggressively do not have the intention of biting; rather the charge, bark and growl are just a threat to get you to go away. When you stand still instead of continuing to move, they bark and back away and if you step towards them they back away faster. So once you’ve stopped and they realize you’re not going to run away for them to chase, they will generally walk away on their own. But you can also back away slowly in a ho-hum, relaxed manner. Once you’ve built up some distance you can turn and continue on your planned route.
Some dogs run out towards you because they’ve just practiced barking at things that go by and when those people continue to pass, the dogs learned that barking and chasing work. They’ve done this so much without thinking that they have no clue why they are barking at you. They may actually want to play, but in their hyper-excited state, if you yell or swing your arms around, they will get more excited and just grab whatever