Now the question at hand is range. First let me say that if you can play a high F or G then what's the big deal? Another half an octave or even another octave is not going to line your pockets with gold. Mostly only other brass players care how much range that you have and we will never make a living off of other musicians.
The people who will pay your salary want 3 things TONE, TONE, and MORE TONE.

Make music, sing through your horn and people will WANT to hear you play. If however your range is a high d or e then a couple of extra notes will not hurt.

Adding this extra range does not require weight lifting or lip pushups. It only takes the right technique. Do you really think that Maynard in his 70's or Phil Driscol a solid 140 pounds are outstanding physical specimens? Can they run marathons or bench press 600 pounds? No they are normal people who were taught how to use their airstream properly. In fact if you are in good enough shape to cough or sneeze then you can LEARN how to PLAY (not squeel) two octaves over high c. I started to learn the trumpet in June before my freshman year. By September when school started I was PLAYING over high c. By teacher at that time was Arthur Ford and he learned to play the trumpet from H.L.Clarke. I am constantly amazed when I hear people talk about years of training to get to play a high c. These people are trying to make the face and lip muscles build up the tension to play high. This is a limited embouchure. It can not work. Think about the strength required middle c takes twice as much strength as low c. Each octave doubles the needed strength. From low c , middle c 2X, high c 4X, super c 8X, triple high c 16X the force.
Lets get real for  Maynard Ferguson to play all night at over 70 years old and still scream out those notes then there must be another way. There is a lip curl. Curl your lips in slightly. Not that much just a hint of curl. As you gently and I do mean gently compress your lips then the compression will add to the curl. The curl fights the airstream. The air is forced to blow the lips outward inorder to escape. This creates a great deal of resistance with almost no physical stress. You merely put the lips in the way and let the airstream do the work. It is very hard to retrain yourself. Years of using way too much compression and mouthpiece pressure are hard to overcome. Is it a radical new idea? NO read Raphael Mendez' book , or Dr. Stevens , or Max Reinhardt' they all taught this. There is a huge difference between how real pros play and how 99% of the people are taught. Did your first teacher even play trumpet? Was he a drummer or sax player? If he did play trumpet could he scream out two octaves over high c? More than likely he was either a non player or a minimal player. He meant no harm and he did the best that he could. But if you have a real desire to learn then you searh out teachers that CAN do it. I changed colleges because of the trumpet teacher. I called , and wrote and bugged everyone who could help me.

Some answered some didn't. Some answered after 4 or 5 tries when they were sure that I was serious. What real effort did you make to improve? You are responsible for your own future not someone else.

'Pops'
http://www.Bbtrumpet.com/