This isolated movement allows you to focus on one arm only. You can focus on the pull, the recovery and on the timing of your stroke, without making it too hard. In the single arm butterfly, you hold one arm straight in front while the other arm is swimming butterfly. You can do this drill with just one arm, but you can also alternate arms.

How to do it 

• Swim butterfly with just one arm and keep your other arm straight in front of you. Start the pull-through with a high-elbow catch and then accelerate your stroke to a strong push-out


• In the recovery, let the arm fly sideways to the front, keeping it straight but relaxed


• Breathe to the front. And kick strongly twice during each arm cycle

Focus points 

• Since you isolate one arm, start with a good early catch and then accelerate to the push-out. Make sure you push the water back, not down


• Lift your head up slightly when pushing out at the back. Find the perfect timing


• Make one kick at the push-out and one kick at the hand entry. Count your kicks to stay rhythmic


• When alternating arms, make sure you keep the arm that is not moving straight in front of you and in streamline

Coach tip

Alternate arms with this drill by either one left, one right or doing 25 meters of each arm. Once this drill is going well, you should be moving smoothly without needing to use too much energy.