It doesn’t matter whether we are talking about a lion or any of the big cats (and include the puma), the experts say the same thing namely that you must stand your ground. You do not want to act like a prey item and run because it triggers the hunting attack instinct. There’s no way you’re going to out run a lion which has a top speed of about 50 mph.
So all the advice is to stand your ground and make yourself as big and as dangerous looking as possible. A tracking instructor on Quora.com advises that the first thing you should do if you come across (highly unlikely for me) a growling lion is to freeze and to avert your eyes. Don’t point at the lion.
If the lion shows signs of stalking you, you should put your arms above your head (I guess to make yourself bigger) and shout your head off. In other words you make a lot of noise which might confuse the lion and make it unsure of what it faces. I believe that this is based on the fact that the usual prey animal for a lion is relatively silent. If you do the opposite the lion might be confused.
You should also throw something at the lion if you have the opportunity. If the lion charges you stand your ground. This is probably the hardest thing to do. If the lion stops approaching you should back away slowly facing the lion but if it starts to move again you should stop and wait.
As the experts say, it is very difficult to carry out these instructions because the natural instinct is to run like hell. It would be a death sentence if you did. You’ve got to stop the prompt for the lion to attack you. When a lion charges it roars which is highly intimidating. All the more reason to have the feeling that you need to run.
Throughout the “stand-off” you should face the lion who might make some mock charges. Male lions are very aggressive during courtship and should not be approached even in a vehicle, says one expert. And lionesses with cubs are protective and should be respected and given space. Also, lions are predominantly nocturnal and I’m told they lose their inherent fear of humans at night time and are therefore more dangerous and more likely to attack. People should avoid camping in areas of high lion density and a watch should be set up if there is concern.