You can’t flex if you can’t lift your arms.
Your shoulders are one of those muscles that you don’t really think about until using them becomes more difficult. Strong shoulders help you to lift things over your head, which is useful both for general workouts and day-to-day life. Have you ever tried to get a box of cereal or something off a really high shelf in the cabinet? Yeah, that’s all shoulders, baby. To develop strong shoulders, you need to work them from all possible angles so they can turn, flex, and extend with minimal difficulty. The best way to do that is with a couple of comfortably-heavy dumbbells and a little gumption.
The dumbbell shoulder press is a classic move without too many moving parts that’ll work your anterior deltoid. Just bring your dumbbells up to the sides of your shoulders, and carefully lift them up and over your head until you’ve completely extended your arms. Bring them slowly back down and repeat, making sure to keep your core engaged the whole time; you need to support yourself from the middle or you’ll topple over. Remember, you should be feeling the pressure in your shoulders; you might be instinctively using your other muscles for this, so try changing your position, such as a sitting one, to mix it up.
Speaking of positioning, you can also try the dumbbell incline row, which utilizes an inclined workout bench. This one will work both your medial and posterior deltoids at once! Simply lay down on your stomach on an incline bench, let your hands with dumbbells hang down to your sides, and use your shoulders to lift them up to about half the bench’s height. It’s a simple exercise, but with enough reps, you’ll really feel it.
With strong, rounded shoulders, you’ll be able to grab stuff off even the highest shelves forever. Trust me, when you’re old, that’s gonna be really impressive.