Push a jogger - it's funny?

Visualise this: You have just finished a 3km run. You are warming down on the top of a cathedral, overseeing the (Guildford) town centre. You are trying to have some tranquillity. To warm down, you are stretching one leg (backward) and standing on another leg. You are trying to manage your body balance. At this moment, two young girls (aged between 18-24 years) are walking past. Suddenly, one of them is trying to shake you and saying that 'Stay balance and don't fall down' or something like that. Will you be annoyed by her behaviour? I would be. In fact, I was extremely annoyed by her behaviour. I frowned, stared at her and asked 'Why do you do that?'. She looked at me strangely and casually replied 'I am just trying to be funny'. Sorry, I did not think it was funny at all. The two girls giggled and, then, walked away. Since when it is socially acceptable to shake or push a stranger while he or she is warming down? If I were to repeat this behaviour to a female jogger, she might shout 'sexual harassment' or, worse still, she might give me a slap on my face. If I were to repeat this behaviour to a male jogger, he might give me a punch (not a fruit punch for sure). What was the young girl thinking? What fun did she get out of it? If she wanted to have fun, go for a run, go to a movie or gossip with her girlfriends. Shaking a jogger who is warming down is, definitely, not a fun thing to do. Young girls out there who are reading this blog, please DO NOT push a jogger while he or she is warming down. It is not funny, I can assure you that!