Cover a certain distance or length of time swimming freestyle (front crawl) breathing in the following ways:

• exhale for 3 strokes after the inhale
• exhale for 5 strokes after the inhale
• exhale for 7 strokes after the inhale
• exhale for 9 strokes after the inhale

Note: The longer the exhalations, the tougher the exercise. A good starting point to get a taste is to cover 200m exhaling for 5 strokes after every inhalation.