Extra effort

These challenges are the minimum requirements for a soldier to be considered for the unit that escorts the national flag from the Gate of Tian'anmen.

In 2014, Chu was selected as the "benchmark" soldier of the formation. He stands to the right edge of the first row of the formation and all other soldiers follow his lead.

"It means every single move you make has to be textbook," Chu said.

To improve his steadiness, he practices by marching on sand in order to better control the sway of his body. He has also tried to march in a straight line wearing a blindfold. "I have to make extra efforts. If I can't march well, it will affect the entire formation," he said.

The focus of the formation is the flag bearer, and the position comes with great responsibility. No mistakes are allowed, and the job is considered more physically and mentally demanding than the others.

Zhang Zixuan, 27, joined the military in 2010 and has served as the flag bearer for about eight years.

Training for the position involved carrying a 15-kg flagpole while running 3 to 5 kilometers. To practice keeping the flag steady, he attached sandbags and two water-filled kettles to one end of the pole.

"When you advance toward Tian'anmen Square, the movement of your body and the pole have to be completely in unison," he said. He added that when he first started carrying the pole it would hit his neck and collarbone, but he eventually formed protective calluses on his skin.

During the flag-raising ceremony the flag bearer has to unfurl the 17-square-meter standard into a fan shape in the air, with his arms stretched out and his body straight as a ramrod. The action requires great strength, and Zhang Zixuan practices the move by lifting a 5-kg dumbbell in the air and holding it steady for a few seconds before taking it back to his chest.