Progress is the way of life for anyone who exercises, especially for someone who is doing resistance weight training at the gym. But why do most people stall at a certain weight and do not improve anymore. There could be several under reasons for stalling to happen. Stalling comes in two ways, either from the inability to push or pull more weight or the inability to do more repetition.
In short, all the problems that cause stalling are because of a break in the system of your workout. The largest contributor is incorrect posture. An incorrect posture will lead to training the wrong muscle and that is why you do not see the progress anymore. What is worse is when you injure muscles like your legs and back which causes a habit of them stepping in whenever the weight is too heavy, resulting in them becoming weaker due to the fact that you do not use them properly. If your base is weak, it will no longer accept any more weight to bear on the top and that is why you could be stalling. Take off the weight along with ego and restart by doing extremely lightweight, preferably only with the barbell or the lightest dumbbell in your gym. Put the pride away or you will retire from training in the gym.
The next reason you would could also be the workout itself is not fully rounded. Imagine that you are training for hypertrophy for your muscles and you see progress and add up more weight for you to push or pull. Soon, you realized you are adding less weight and in the end, you will hang at a certain weight. This could mean that it is time for you to change up your exercise. Unless you are training on strength and taking a diet where you gain weight, you can not simply do the same workout again and again and expect growth because everything you require requires strength as a pillar inside to progress. So you will just have to settle with changing up the exercise since you have already plateaued on that exercise for now. This also affects people who are training endurance at the gym with high repetition and low weight used.
Lastly, it could be your diet. If you are training long hours at the gym, it could be your downfall instead of progressing you. The body enters a catabolic state an hour or more after intensive exercise at the gym which leads to your muscle breaking down as the glycogen storage in your muscles are stripped of fuel. The second mistake is consuming less of what you need. This is a sure fire way for you to demoralize and stop yourself as your body only grow when there is sufficient vitamins, minerals, protein and fuel. Lack any of these and soon you will see yourself staying the same size no matter how much you train. The biggest mistake I see when it comes to recovery is the fact that people do not rest enough. They over-train the muscle by training the same muscle again within 48hours or they simply do not sleep enough each night. Muscles grow mostly in your sleep so please stop hampering your growth with the late night movie and the late night up in front of your laptop.