Writer's Advice and Feedback Group discussion

My lungs are burning and my chest feels raw as I desperately gasp for breath. The sweat on my forehead is running down my face and into my mouth and I can taste the salty perspiration in my mouth. My mouth is dry but there’s a wet texture in my throat. I spit and red sticky liquid flicks back into my face and tangles in my hair. There’s a dull ache in the back of my skull as I run and with each vigorous new step I take, a sharp pain shoots up my right leg.
As i approach my next jump I predict the length of the gap between this building and the next. My muscles flex and I feel goosebumps running the lengths of my arms. I let out a shout as I throw my body over the edge.
There’s a sharp cracking sound as I land and concrete shatters around me like rainfall. I let myself fall onto my back and let the blinding sun dance across my skin. My clothes are soaked with cold sweat and my stomach churns. The sharp pain in my leg has now proceeded into a searing pain which makes me feel dizzy.
I wait for the sound of his high pitched maniacal laugh for several minutes. Nothing happens and I feel both disappointed and delirious. I continue laying there waiting for the sun to fall behind the horizon. I stretch my lips into a smile as the darkness leads me into unconsciousness.

This is your first chapter?

yes I've changed it a lot since then

From what is here now, I suggest you lengthen this. It's around 250 words, and although there isn't a set rule for chapters, it's a good rule of thumb to have each around 2000 - 5000 words. With each chapter housing 1 - 2 scenes and with each scene 2000 - 2500 words. It can feel too short otherwise.

Great writing though. :)