Excerpt from www.swimsmooth.com
Chinese translation by Rebecca
Why Is Body Roll So Important ?
Body roll is a very important part of your stroke technique, so much so that we call it a fundamental of freestyle swimming. There are many small technical reasons why body roll is important but here are three main ones:
1. Easier Arm Recovery and Injury Prevention.
Lie in a flat position on your front and try recovering your arms over the ground like you are swimming.
Even if you are very flexible in the shoulder it’s very hard to do this. You’re going to struggle to clear the water’s surface when you’re swimming.
This awkward action puts stress on your rotator cuff muscles as you perform it.
Also notice how the hand has to lead the elbow to get round – this swinging path has momentum and when you enter the water at the front of the stroke your hand will want to cross the centre line.
Cross-overs put even greater stress on your shoulder and are a leading cause of shoulder injury. For more information see our technique article on
Try now lying perfectly on your side with the bottom hand out in front of you.
See how it is now easy to recover the arm high over the water. The shoulder is much more relaxed or ‘neutral’ with this technique.
This high arm movement is purely ‘up and over’ – there is no swing to the side. This removes the tendency to cross the centre line at the front of the stroke because there is no sideways momentum during hand entry.
Practise leading with the elbow until your arm passes your shoulder.
同時注意你的手需如何帶領肘部完成動作 – 這個擺動路徑有動量，而且你往前入水的手臂，會想要越過中線。
2. Using Your Larger Muscles and Core For Power
When you roll from one side to the other you transfer the power from the rotation to the propulsive arm in the water. By rotating with this action you are using your lats, pecs and core muscles to power the stroke. This is a good technique because these muscles are very strong and powerful.
Conversely, when you swim with a flat body position you are only using your shoulder muscles to power the stroke. These are a lot weaker than your chest and back muscles. Using these small muscles as the main source of propulsion puts a lot of stress on them.
3. A Longer Stroke
When you rotate well you are able to reach further forward. As you catch the water at the front of the stroke you are able to do this earlier and more effectively.
This means you will travel further with each stroke – taking less strokes to cover a length of the pool, up to a point this is considered good swimming technique.
這意味著你每一划水會讓你滑遠一點 – 用較少的划手次數完成一樣的池距離。在某種上程度上，這被認為是良好的游泳技術。
Excerpt from: www.swimsmooth.com with my translation in Chinese