Nothing is more frustrating in the gym than hitting a plateau over and over again. It just seems like you are not making any progress as time goes by.
You go to the gym pumped up for your workout, determined to completely destroy it this day and give it all you got, and you still hit the same weights as last week. This process repeats itself multiple weeks and you start lifting the exact same weights week in week out..
Why do we hit plateaus?
The human body is created to adapt to stimuli, and to maintain a normalized state which is called homeostasis. Your body wants to stay the same. This is great for survival, but we are trying to build muscle here. As you train for a longer time, your body gets better at adapting to training, and this is where many people fail. They simply do not put in enough effort to keep progressing.
So if your noob gains are behind you, you have to get off your ass and work as hard as possible to force your muscles to keep growing.
The primary factor for muscle growth is progressive overload, stimulating your muscles harder as time goes by (increase resistance). This is why a plateau in muscle mass, happens due to a plateau in strenght. People who look the same for a whole year, are lifting more or less the same weights all the time.
What is a true plateau?
Often people think they hit a plateau, simply because they are just not progressing as fast as they would like. However, unless you are completely new to lifting, you will not be able to add weight to your lifts every week and maintain the same form. When you are an advanced trainee, you should aim for increasing at least your first lift by 1 or 2 reps. This is enough to create overload and stimulus to your muscles.
For example, if you hit 225 pounds on the Bench press last week for 3 reps, you want to hit 4 reps this week and 5 reps next week. That is great progress!
Keep in mind, slow progress is still progress.
In a true plateau, every lift is stuck at the same weight for at least 3 weeks in a row.
#1 Technique and Mobility
Wrong form can kill progress, especially on compound movements like the Bench Press, Squat and Overhead Press. If you are performing an exercise with improper form, you will plateau, and if you try to break through it, you might get injured.
Make sure you have someone take a video of you when you are stuck at a certain weight (or even before to prevent it) so you can review your form. If your form is incorrect, adjust it and build back up with lighter weights. This can lead to a very quick plateau boost.
A lot of times, improper form has to do with mobility and flexibility problems. This may unable some people to do certain lifts. There are many exercises for mobility and are found on YouTube for example.
#2 Not Sleeping Enough
If you don't sleep enough, your body will not perform at its best, especially when it comes to lifting weights. Sleeping is very important for recovery and performance. Studies show that sleeping 3-6 hours per night compromised strenght and increased fatigue during workouts. Other studies show that milder sleep also compromise the body's ability to recover from workouts.
So how much sleep do you need?
You do not need crazy amounts of sleep. The recommendation for sleep that's generally needed is 7 to 9 hours. Athletes would need a little more sleep which would result in 8 to 10 for optimal results. Some people do fine with less, some with more, it's all different per person. This will give you a good indication though.
This is probably the most common reason that people plateau. When you just started lifting you have never experienced overtraining, because that usually kicks in when you get more advances. At some point, your Central Nervous System (CNS) is simply fried and that is the reason your weights are not increasing. When overtraining kicks in, the first thing that you notice is a decrease in strenght and muscle endurance. If you try to battle this, there is a great chance you will injure yourself. I have had this experience in my early lifting years.
The only thing that truly fixes the problem, and it's easy, is a deload week or a week off. (This should be implemented in your workout routine already, but if you notice overtraining before your set deload week, you might have to plan an earlier one.) If you come back after this week, you should start with a little lighter weights as you did before and build back up. If you notice that your progress is still stalling, it's probably not an overtraining issue.
Many times, a plateau is caused by simple not eating enough. This is a very common problem. Some people just have to eat insane amounts of calories to gain muscle mass and to progress. Myself for example. I need up to 5000 calories in my bulking phase to gain muscle mass. For some people this might be unreal. There are even some beginners that need 4000 calories to grow. Without those calories, they will not see any results.
As you get bigger and stronger, your caloric needs will increase. The same thing as slowly decreasing calories while cutting bodyfat, you need to slowly increase calories when trying to gain muscle mass.
I suggest to increase your carbs by 25 grams if you are hitting a plateau. Look back after a few weeks if you progressed, and if not, keep increasing by 25 grams.
#5 Play With Rep Ranges
If you are stuck at a certain rep range, and you just can't move up in weight, you could try to play with different rep ranges. Try to go a little heavier, with less reps and see if you body will adapt and if you can build back up with that weight again.
For example, you are working in the 4-6 rep range on the Bench press and you're stuck at 225 pounds for 5 reps. You can move up to 230 and only do 3 reps (not to failure). That next week, you will hit 230 again and now try to hit 4 reps, the week after that 5 reps and then you will have busted through your plateau.