I do powerlifting training twice a week. One day a week for volume. One day a week for strength. The remaining days I do isolation exercises for arms, legs, chest, shoulders and back.
Powerlifting training focuses on the three fundamental diciplines: Squats, Bench Press and Deadlift. Each of these exercises are wonderful for activating multiple muscle groups and activating stabilizing muscles in ways you can’t achieve using machines.
While I don’t compete any more, I still train using a program that assumes I do. It gets more challenging every week until you do one rep maxes, then go back to much lower weights, starting the cycle once again - slightly heavier than before.
Feel free to check out my program (Weights are in Kilograms)