Close-grip bench press.
Begin lying on your back on a bench, with a barbell racked directly over your chest. The barbell should be racked at such a height that you’ll be able to unload it from the hooks while lying flat on the bench.
Grip the barbell with your hands shoulder-width apart. Then unrack the bar from the hooks and pull it down to your chest, keeping your elbows close to your ribcage.
Lightly tap the barbell to your chest just below the sternum, then press it back up until your arms are fully extended. You should feel the emphasis in your triceps.
Keep your feet, butt, shoulders, and head in constant contact with the bench and ground.