three fingered wave

When I cross paths with other runners it seems natural for me to give a little wave of acknowledgement and encouragement for a person that is choosing to be out participating in the same activity. I'm more likely to wave if I'm on a trail - somehow the sidewalks and streets have become all business. 

Hikers will often do this, too. Maybe that's where I learned it. They'll even say Hi or stop to exchange information. 

Bicyclists do this. Usually just a wave or a nod of the head but only, seemingly, if you're dressed in the same manner and/or riding an equivalent or better bike. 

On longer runs I carry a water bottle in one hand. Sometimes I'll switch the bottle to my outside hand so I can wave with the closer hand to the other runner - I'm not sure why but maybe it just seems more welcoming. 

Sometimes I don't switch the bottle but just raise three fingers while holding the bottle with the other two. I do this when I get tired or someone appeared unexpectedly or I've already waved to the same person earlier in the run.

Some people refuse to wave back. Or say Hi. Or smile. Or acknowledge my presence in anyway. Maybe they're lost in thought. Or have a different perspective on what it means to be a part of the running community.