Training the mirror muscles is most certainly enjoyable. You can see the muscle working and the blood rushing in to fill it to capacity and give you that elation of the pump.
Training the anterior chain (muscles in the front of the body) is preferred by many because of the following 3 reasons:
1 – You can see them.
2 – They’re easier to train than their counter parts (posterior chain).
3 – You’re a tad vain.
When it comes to having a balanced body a lot of people fall woefully short because of how much they neglect (legs and back), however failing to train your posterior chain will result in you leaving lots of potential growth/strength untouched.
Don’t quite believe it?
Here is an example:
A lad wants a better bench. He trains it religiously and starts to make some impressive lifts until he is forever handicapped when he tears his rotator cuff or pec. Game Over.
Stories like this are common because people lift with their ego and not with their brain. If you try to build a building and only make one wall eventually it will fall over and break because nothing else is supporting it. Your body is the same as a house, it need solid foundations and structure before you worry about what colour to paint the front porch.
Having a strong posterior chain will help you with the following:
Squats, Deadlifts, Bench Press, Shoulder Press, Carrying Heavy Objects, Sprinting, Jumping, Climbing, Posture and basically make you more robust in daily life and prevent lower back problems.
For every pushing movement you do, you need to perform two pulling movements. Follow this rule and you will find yourself largely injury free, ignore it and you can simply reminisce the days when you had a good bench.