Confusion About Muscle Confusion
P90X heavily promoted the concept of muscle confusion and the infomercial was a huge success. While variety is definitely a good thing in your training, consistency is absolutely necessary for optimal results. You definitely shouldn't strive to always "confuse" the muscles. Certain lifts can and should be performed week-in and week-out for your entire training career.
A Better Way
Prioritize 1-3 exercises for 4-6 weeks at a time, hitting them first in the training session with a progressive loading plan.
For example, you could squat and/or bench three times per week for 4 weeks in a row in varying rep ranges, such as:
- Monday: 4 sets of 6
- Wednesday: 4 sets of 2
- Friday: 4 sets of 4
After the 4 week cycle, you can test your 1RM, deload, and then repeat the process with new exercises like deadlifts and/or military presses.
After the hard stuff is done (squats and bench, in this case), then use variety and simply hit the other muscles of the body with whichever exercises seem ideal at the time. Aim for 2-3 sets of 6-20 reps. Make sure to include compound and single joint exercises that combine to work the entire body.
If you consistently set personal records while making sure to regularly activate all the muscles to high degrees, your muscles will grow over time. Gaining strength and setting PRs is much easier when adopting a periodized approach rather than just winging it and doing something different every time you enter the gym.