Almost 50 years ago I had 3 times a week program with 15 different movements. I developed a lot during 3 years of this same program, but then I hit a plateau. No more power, no more strength, no more mental or intelligence or interest to continue training like that.
Now, at 75, I have learned, that one must have a lot variation, change both the program and the way of doing workouts and movements in a more intelligent and productive way.
That is, why I want to protest against the usual, too usual way of instructing people to train the same movements 3 times a week. It really does not work that way.
Now I am training 5 days a week, every time different muscle groups.
I feel, that it is one of the best ways for me. I really do not want to overtrain in any way, I do not want to kill myself exhausting my body with too much work for one day. I train about 50 minutes at a time, doing Squats for example for 19 minutes only. I really feel good after a short training.
I am doing up-hill-sprints on a near-by hills now and then. My record is 22 sprints in under 30 minutes up-hill. #0 to 90 meters at a time and slow walking in-between. My pulse was a few times only 70/minute right after the few last sprints. Really wonderful, because I never was a marathon or shorter long distance runner.
I have experienced, that the best way to add power and stamina and to reduce excessive fat is doing up-hill-sprints. But never do them too often to not get burned-out. Only, when you feel good and are in good health.
One other very important thing to do is to sleep 10 or more hours a night and to get a few 15 minutes naps during the day, if possible.
Best Regards my friends, be happy and prosper.