The deltoids are the largest muscles on your shoulder. If you want them to look like grapefruit halves stuffed into the top of your sleeves, then you need to do the lateral raise.
This exercise targets the lateral head of the deltoid. The bigger this middle portion of the muscle gets, the wider your shoulders look, says trainer BJ Gaddour.
Do the exercise while balancing in a side plank position and you’ll also challenge your obliques.
Gaddour demonstrates how to do the side plank lateral raise in the video above – along with two other core-taxing twists on the lateral raise.
Pick a variation and perform two to three sets of 10-15 reps on each side. Or try a time-based protocol: perform reps on your left side for 30 seconds, rest 15 seconds, then perform reps on your right side for 30 seconds, followed by a 15-second rest.