"If you are going to lift that stone, you need to sit back more. Focus on the muscles running up your leg and feel the connection at the hips with your back straight." Ella saw that Brad was focusing on the basics of basics. He was helping the clean up from the battles.
But when she had noticed that he was trying to lift heavier and heavier pieces of rubble, she had to step in. While she did not have the strength training by comparison to Brade, she still had the knowledge.
When they had all begun training more seriously in Terra city with the focus on their bodies, Ella had made sure that she gained some knowledge about the best way to go about all of it. The best forms for lifting heavier weights. The best methods to build muscles. She had to know this since her older brother also had a very big focus on physical strength. He had taught Maria after all.
Creation is hard, cheer me up!