Hi. I’am 21years old and since i was 14 till around 17 all i did was sitting in front of computer all day, either playing games or doing other stuff. At 17 i finally started doing some exercise. First i tried running which i quite liked even though i was slow like a turtle. I then tried road cycling because there was some organized group rides in the zone and i tought it was really cool. Indeed it was, i loved it from the first pedal stroke and have been doing ever since.
During that time i have gotten much fitter. I was in really bad shape before even tough i wasn’t fat. My resting heart rate dropped 20 bpm and my endurance obviously went through the roof.
For a while i wasn’t aware of my muscular imbalances but i started to pick it up from various things. Mainly my pedalling which i never felt natural. I also noticed that the pros i rode with had much bigger asses than mine and more strenght in general in that part of body while i was very quad dominant.Till one day an ex pro told me i wasn’t using the glutes in my pedalling. I confess only after that day did i realize there were muscles there and that i was supposed to use them lol
So i’ve been searching the internet how to correct my problems but there’s so much information that i don’t know where to start. So i tought you guys might help me with more concise and specific advice. Here’s the list of problems i have(there’s problably more i haven’t picked up…): anterior pelvic tilt, tight hips, tight quads, no hamstrings and no glutes.
I’ve doing hip stretches like the kneeling hip stretch because they say tight hips disable glutes. I also plan on doing myosfacial release to release the tension in my quads and hips, i’am just waiting for the balls and foam roller to arrive.
I have tried some glute bridges but i have a hard time doing them correctly. First i can’t get up too much because of the tight hips and also i can’t make the back not do any work. I do feel the glutes contract but so does the back which i think is not supposed to.
Here are 2 photos from me doing the kneeling hip stretch so you guys can better assess my situation. As you can see there’s a big gap around the glutes, there should be muscle there 
Here are some photos from where i would like to end up which are from a successful pro road cyclist. I don’t know if u guys can see well from photo but he has tons of hamstring and glute strenght.
And yes i know i don’t have much upperbody… :b that’s not a priority right now even tough i could defenitly make use of some strenght there which is something for the near future. Right now i really need to adress this problem because i believe correcting this will help my posture which is bad right now and will also help my cycling because the more muscle we have in the legs to power the pedals the better 
This if there is any hope for me. It’s probably not so easy to correct dysfunctions like this accumulated over the years.
I appreciate any help