I love this photo. It really reflects the concentration that runners have at a marathon. The composition and crop are awesome - and I like the BW treatment, too.
Excellent shot! I like the grain and BW. I love the scene and find myself scanning over the faces and activities of all the people - this pic has great interest appeal for me!
There is this guideline for photography, and one of the guides states the "rule of six".
The rule simply is this...don't have more than 6 athletes in the same image because it starts to get crowded.
Not only is the rule of 6 ignored in this image, but, a sports photograph should be about the athlete meaning tight crops, shallow depth of field, blah, blah.
Comp could be tighter, light good, texture good, blacks just a bit deep, whites just a bit blown, too busy, eye movement poor, over all just an ok image.