Strength endurance is a great to build lean muscle, and learning how to build long lasting strength. Strength endurance leads to building volume, which impacts the amount of work you are able to handle. Strength endurance can help increase the time it takes to fatigue, becoming more efficient.
Diet manipulation is very important. Learning how to fluctuate protein, carbs and fats is also a critical part of strength endurance training. Working large muscle groups, performing more work, and handling more physical stress.
Posture is one more critical area and must be worked on. Proper posture leads to strength gains as well. Working more efficiently. Also concentrating on breathing. Everything is connected.