as PK99 says training runs are different. I've been out with a club that made it clear - if you were dropped you were on your own. I remember somebody going off the edge of the road, into a grass ditch. Soyanara!
There are exceptions. The Cheam and Morden has a lot of ex-racing cyclists (I've been out with a pair of brothers who were tandem champs in the 50s). There's sometimes a bit of sprintfoolery at the front, and on hills for an imaginary jersey - and there's usually a sprint for the cakes at Capel. And if you've seen those cakes, you'll know that they are worth sprinting for. When I went out with them I usually had the fastest bike and I was usually the youngest (sometimes by quite a way) so I'd always win the sprint for the cakes. Form dictates that one takes extra time parking one's bike to allow the more senior members first crack at the tea.