Here's the thing... people have a gross misconception about what is achievable result-wise. Because of the way everything training-related is advertised we now believe that we can COMPLETELY change your physique in a few months.
You can't do that!
Well you can...
If you already have plenty of muscle BUT have a lot of fat so you look like crap. Simply losing all the fat while maintaining most of your muscle can turn you from looking fat to looking jacked. But if you don't have the muscle to start with, it wont work.
If you once had a very good physique, stopped training for a while and got out of shape then begin to train hard an eat well again. Muscle plasticity is real: regaining lost muscle that you once had doesn't take that long. For example I used to train a lot of pro hockey players. During the season they would routinely lose 15lbs of muscle (sometimes more) because they only did 2 lifting workouts a week, played and practiced hockey every day, didn't eat as well, etc, During the first month of their off-season they normally would gain that 15lbs back.... so it looked impressive: gaining 15lbs of muscle in 4 weeks. In reality it was just regained muscle. Past the beginner state it is RARE to find someone add more than 10lbs of real muscle in a YEAR.
If you decide to use steroids for the first time. Then yeah, you might gain 20lbs of muscle and get leaner in a few months. Note that I mention "for the first time". Because after that first cycle, drug using bodybuilders progress at a much slower pace. I worked with an IFBB pro bodybuilder who gained about 5lbs per year and was really happy (he did gain 40lbs of muscle in his first two years then 3-5lbs per year after that).
If you were severely underfed and undertrained (think anorexic model doing tons of cardio) and decide to train hard with weights and eat a ton. You body will be primed for growth and you will have an accelerated rate of progress for 1-2 months.
But except for these situations (and maybe a few exceptions) "normal" individuals do not gain 20 or even 10-15lbs of muscle tissue in a 2-3 months (yes they can gain 20lbs of weight, but not of pure muscle tissue). Dr.Fred Haltfield evaluated the maximum rate of muscle growth to be about 0.25-0.5lbs per week.. so AT THE MOST 12-24lbs per year. And I'll be honest I've rarely seen someone gain 24lbs of MUSCLE in a year. A lot of people dilute themselves into believing that they gained 24+lbs of muscle. In reality a lot of it is fat, water and glycogen. Past the beginner state 10lbs of MUSCLE in a year is really good. Might not sound like much but that is 30lbs of muscle in 3 years and it will make you look completely different.
And that rate of gain is when you do everything right training and nutrition-wise and do not have an excess of stress in your life.
At 50+ years of age, if you are not taking performance-enhancing drugs I would personally find a gain of 5-7lbs of MUSCLE in a year, pretty good.
I KNOW it sounds demoralizing. But that is the truth.
I could tell you that you can easily gain 20lbs of muscle while getting shredded. But I'd be lying to you. It would give you false hope and you would end up disappointed and stop training.
Here's the real secret: if you want to achieve anything worthwhile physique-wise you must focus not on the end/goal, but on the journey. You just fall in love with the process, not with the end result.
Those who focus only on the end results NEVER achieve it. Only those who fall in love with the process.... fall in love with the hardship of training, the discipline of dieting and accepting the pain of sacrificing some things you enjoy just so that you can improve your body... only these people will achieve the physique they want (unless they are genetic freaks, which you aren't otherwise you wouldn't come here).
Can you build the physique you want at 53?
Maybe. But maybe not.
Can you get better? YES! Definitely. How much better is up to you. How much effort in the gym are you willing to give. How disciplined can you be with your eating?
But at 53 I'll be honest, the clock is working against you. Physiology evolved with age and it IS a lot harder to build muscle and get leaner as you grow older. I know that at 40 things are MUCH harder for me than when I was 25. I'm still in great shape. Muscular and lean. But I'm smaller than I was at 25 despite doing things even better.
That having been said I have worked with tons of people in their 50s and 60s who were able to improve their physique. But honestly, mostly by becoming leaner and maybe adding a little bit of muscle. I have rarely seen a "natural" (not using hormones) 50+ individual pile on a lot of muscle. And the few that did, had to get a lot fatter in the process (which is not acceptable IMHO).
If you focus on achieving a certain physique, you never will and you will get discouraged.
If you want to achieve significant results you must focus ONLY on the process. What can you do better TODAY versus yesterday. THAT'S IT.
Stop worrying whether you will be able to get the body you want. Only worry about doing things better and be in love with the process.
The way I see it is you must love training so much that you do it even if you COULD NOT improve at all. Personally even if I knew that I could not improve even 0.01% I would still train. And would train just as hard as I'm training now and just as often. Because I love the effort, I love the daily struggle.
I'm reading a really powerful book at the moment "The subtle art of not giving a fuck" and that's his exact message. And one thing the author mentions is this: do not ask what you want out of life, everybody has roughly the same type of answer... what you really need to ask is what pain are you willing to go through in life. THIS will tell you a lot more about what you will accomplish.
I posted something on my Twitter account a few weeks back... it went something like this: "Tons of people dream about being the best (or having a great physique) but few dream about what they need to do to get there".
Bottom line. Change your mindset or your will NEVER reach you dreams. I know it sucks to hear but it is the truth.