Makes it make sense why I can feel that doing abdominal work has a direct impact on my improvement.
I know I do a lot of things that waste energy and are not efficient in my matches. For me, making my contact and my strokes more efficient is what I need to improve and I notice when I do this, my speed, my ability to get to the ball, my footwork and the power translated to the ball all improve. It helps having someone who knows how to coach in your corner.
When you contact the ball (timing), quality of contact and what part of the ball you contact are part of making your stroke more efficient. Then there is biomechanics. When your movement is as direct as it can be, you will need to use less effort.
Efficiency: achieving maximum productivity with minimum wasted effort; that is what you are looking for.
One more thing,
Ma Long often looks like he is taking swings at 120% of his maximum power.
He is so fast that he can often get away with this. But it used to get him in trouble.