first u can not reach 1000 per session,it is just impossible to do so,the max number u can reach is 200 to 250 0r 300 max per session,i am a push up expert,take it from me,i am doing push ups since i was a little kid,i am know 20 years old male,and i can do between 75 to 150 to 200 max,if u want to increase ur capacity u must first attain the best quantity and quality out of the 50 push ups,do not do them very fast and not very slow,just normal breathing,head and neck r straight togther,after u have mastered the 50 push ups easily,u can go to the next level by the following tips,before doing push ups inhale and exhale very deeply for 2 minutes,make sure ur body is prepared,stretch ur self a little,especially ur shoulders and hands,then u must be psycologicaly prepared and mentally prepared also,then go to the ground and start doing push ups,after certain number u will feel u can not do any more,it is normal this ur sign or clue to reach the next level,ur body is lying to u,u can do more just use all ur inner deep strength like ur life depends on it and pump all ur juice power in those push ups,u can do it,the world depends on u,come on one more.u can do an extra 10 or 20 push ups each time in this way.although to increase from 50 to to 60 u need a 3to 5 days but from 50 to 100 u need about a month or 2 to acheive that and from 50 to 200 u need a full extensive year train,coz ur body is building up muscles slowly so it takes time,good luck.