It was a good effort to show people in activities as the weather changes into springtime. However, as soon as you open the image the eye is automatically drawn into the horizon. Its the city sky line that is central to this photo. The people seemed secondary.
I can see the idea formulating on how people from the city use the available resources to enjoy and excercise. Again, people in this image are not focus enough. Maybe if this first jogger and bicyclist were closer to camera angle and focal point, it would have been more appealing. I would have cropped the image a little more to the right side, leaving the taller buildings in the background. This would have given focus on the people coming through the shot. That way you could provided more detail and highlights of the types of people and their facial expressions.
Overall a good idea, good lighting. Always think of the purpose of your composition and then recompose it. Good luck in other future challenges.
People seem to be a minor part of your shot. The leading line is nice, but overall the candid/snapshot feel of this image doesn't probably have mass appeal for a challenge site.
Nicely composed. The colour of the water seems overdone, I 'm all for boosting colour, but it looks artificial at the shore edge, as does the orange net fencing in the park area. I think it needs to be rotated anticlockwise a little.