Want to be a pool shark? Researchers in Portugal who tracked elite swimmers confirm what you may have guessed: longer, more frequent strokes are key to swimming faster.

The secret is technique, says University of Michigan swim coach Mike Bottom.

To lengthen and speed up your stroke, he says, rotate your shoulders and hips as you reach forward. “Try to roll your body from side to side.” The result is less drag, longer and stronger strokes and more speed.

Need some more help?

Have a look at these tips from  olympic gold medalist Cameron van der Burgh.