Functions: Developing the flexibility and endurance of arm.

功能：增强上肢耐力和灵活性。

youdao

So in order to move your hand through water which is a much heavier medium than air, it will require more strength - to do that over time requires endurance of your arm muscles.

就像在第一点提到的，这要根据你的划水频率和在水里移动手臂的能力决定，牵涉到力量和耐力。 因为水的密度比空气大很多，不断地划水需要你手臂肌肉很好的耐力。

youdao

The main physical qualities include the speed of moving and swinging the arm, flexibility and endurance.

身体素质以移动速度、挥臂速度、灵活性、耐久力为主要素质。

youdao

The main physical qualities include the speed of moving and swinging the arm, flexibility and endurance.

身体素质以移动速度、挥臂速度、灵活性、耐久力为主要素质。

youdao