If you are also trying to find the ONE method for training, you are at the right place.
To get in shape, build muscle and stay athletic, there is an easy solution. And no it is not going to gym six times a week.
First, build your strength and conditioning to the Simple stardard as lait out in the Simple and Sinister by Pavel Tsatsouline.
It is basically, total 10 sets of 10 reps 1H swings, using 32kg kettlebell, done every 30 seconds, alternating hands each set.
Rest 1 minute
10 sets of 1 rep of Turkish Get-Up (TGU) using 32kg kettlebel, done every minute, alternating hands each set.
If you cannot do that yet, focus on that first. It is a baseline level of strenght and conditioning you need to have if you are serious about it.
And also it prepares your body for more demanding traning going forward.
Once you achieve Simple, then to amplify your growth, you can add more Squats, Cleans, Presses. You can use kettlebells for these as well, so still no need to go to gym.
As long as your diet is clean alkaline and protein focussed, you will be growing without getting fat.
You can also add Pullup program into that Simple training, namely Fighter Pullup Program.
Any other exercises are purely unnecessary. Just keep the things Simple.