One of my close friends is a masters 212 pro, he is 59 this year. He works with a popular coach in Spain. He competed in bodybuilding for over 20 years, and was an athlete in other sports before that.
His off-season is typically 1000-1500/300-600/300 test, eq or primo, and deca. He uses anavar sometimes in off-season. Gh 4-6iu. Contest prep is typical 350/350/350 test tren mast, anavar and winstrol last 2-4 weeks. Gh 6-8iu.
Sometime last year his body stopped responding like usual. Wasn't responding to food, training, or drugs.
His bloodwork showed that his blood glucose, fasted insulin, CRP, ESR (sedimentation rate) were starting to elevate.
He ended off-season and went to cruise 400 test, his inflammation and insulin sensitivity got worse.
Some diet changes, detox, peptides (BPC/TB/KPV,MotsC,Reta) and not much improvement.
He lowered to 250 test, lowered his protein from 300g to 200g, kept carbs around 200g every day, fats are always low-moderate (10-30g added fats), and things started to improve.
3 months later, after more regular cardio (daily 30 minutes LISS became daily 60 minutes, and added 3 HIIT sessions per week), and he's sleeping better, stress and inflammation markers came down, responding to food and training again.
He tried to start an off-season with 750 test and kept food low, but by 3-4 weeks in he felt miserable, fasted blood glucose was >100, couldn't sleep. His body said enough is enough. No more competitions.
Now he is just on trt 250, 3iu gh. Trains 5 days a week, LISS every day, HIIT 2-3 times a week, protein is low, carbs moderate.
Why do I mention this? Some guys are in their 50s and still pushing their bodies to the limits. Some guys are in their 50s just on trt and trying to maintain and preserve whatever health they have. Some guys say it depends on how long you've been training and pushing your bodies, some say neither of those matter. What you do is ultimately based on your goals and expectations, what you're willing to put your body through, and what your body is willing to tolerate. What someone else does might not have any relevance for you or your body. But it can be helpful or at least entertaining to learn other perspectives.