you don’t know that it is. By your own admittance, you don’t see what people are doing in the real world. You also wildly overestimate the progress a beginner should expect to gain in lean mass.
your nutrition is far from ideal for building muscle. Putting aside the veganism, you spend half your time in a calorie deficit. That’s not a good strategy to add 1kg of muscle a month
These are things we know for sure. There are also other potential issues that we can’t tell for sure remotely:
you may not be working hard enough. In terms of intensity, we can’t tell how hard you’re pushing yourself. It can take people a long time and lots of effort to figure out how hard they can push.
you may not be working enough. You are not very strong, so 3 sessions a week is pretty weak sauce. When I wanted to increase my pull up ability, I trained it multiple times a day, as well as climbing (bouldering) several times a week and daily sit ups. I also swam regularly, albeit poorly, see my next point.
you appear to be severely undertrained. I may be wrong, but my guess is that you’ve done very little physical activity before starting calisthenics. That’s fine, but be aware that it will limit your progress. Most “beginners” are teenage boys who have been physically active in some form for many years before starting weights etc.
You may have poor genetics for muscle building. It happens, many people do. You won’t change it so get over it and work harder.
you may have a medical condition that limits your growth. Notice I said limits, not stops. I also left this until last because it is by far, far, the least likely scenario. It is far more likely that you are executing a fairly poor plan, extremely poorly and expecting the largest possible results from it. If you genuinely believe you have medical issues, see a medical professional. The internet is not the place to diagnose medical issues.
Just to reiterate:
You are not good enough at this to be frustrated. What I mean by that is that you are using a sub-par training approach, a sub-par dietary approach and expecting absolutely optimal results. This is not how the world works. You are setting yourself up for failure by:
not getting any of the supposed medical conditions diagnosed and dealt with
refusing to eat in the way that your examples of success eat
refusing to train in the way that your examples of success train.
How would you know? You don’t know what successful beginners do. Maybe training like the successful beginners did when they were beginners? Success leaves clues.
You don’t want to look like Arnold though. Maybe you should train like the people you want to emulate. You want the same progress as the people in the studies you linked, so maybe use the same methods.
But I have never seen a routine of arnold in a forum for beginners.
Usually only people who don’t know much, do routines like strong people, and they then ask why they dont grow.
Hey I have that too. I have a fair amount of muscle too, though. Good thing I didnt find out about my hypothyroidism and low testosterone until I had already built some muscle though, or I would have had to give up after 6 months because you obviously cant succeed with those problems.
This is irrelevant as it is not what I suggested you do. I suggested you follow the routines of the people you wish to emulate from the studies you posted. I assume you actually read all these studies in detail, yes?
We can probably make this simple and answer this directly. @dagill2 i appreciate you have made many of these points, thoroughly and comprehensively but lets try direct.
Here are the 3 most probable reasons why your progress is slower than the average progress of people who do calisthenics.
1 They have a better diet than you
2 They train harder than you
3 They are starting from a higher fitness base than you.
I thought beginners gain much faster than non-beginners.
Not a single person has said this. ← He said train like the guy you wanna be like. Ok. Might be arnold then.
What @dagill2 said was that you have studies of beginners who gained 1kg of muscle per month. They are the people you want to emulate, beginners gaining muscle muscle muscle.