Tambourine Man

I went for a run today.  Beautiful, sunny sky, and everything smelled good because of all the rain we had yesterday.  It was very nice.  I saw something odd though, and I was hoping someone could help me figure this out:

I was on the Mount Royal mountain and coming towards me was another runner.  He was a regular looking, athletic guy; all decked out in the latest running gear.  And he was playing a tambourine.  It was a yellow half tambourine, and he was jingeling it in some sort of beat while he was running.

I had to do a double take.  He didn't look crazy.  He looked like a perfectly normal fellow, probably in his forties.  He had a dog with him, so perhaps it was a training exercise?  Or perhaps the tambourine jingles help him to run faster?

I typed "running with your dog and a tambourine" into Google, but nothing helpful popped up.  I feel like there should be a good reason behind this.  

Any suggestions?