One of the best ways to get swimmer’s abs? Mimic their movements! This vertical version of the front crawl stroke engages your obliques (the abdominal muscles along the sides of your torso), back and shoulders.
To do: Start standing with your feet hip width apart, arms by your sides. Extend both arms out in front of your chest, palms facing down, thumbs touching. Bend your knees and push your hips back behind you, lowering your body into a slight squat.
Sweep your left arm down and back, as you stand up with your legs and extend your knees slightly.
Circle your left arm up and all the way back to your start position, while landing back in your squat.
Quickly repeat with the right arm (imagine you are in the pool and the air is actually water that you are pushing against during the entire movement).
Repeat this move, alternating arms as quickly as you can, for 30 seconds.