Weighted Single-Leg Calf Raise

Stand on one foot with the ball of that foot on a step's edge, holding a dumbbell in the hand on the same side while your free hand steadies you on a rail or wall. Drop your heel below the edge for a stretch, then rise onto your toes as high as you can. The dumbbell adds load without needing a machine to sit in or a second person to spot you, but it also means your grip and forearm fatigue alongside your calf. Lower slowly on the way down; that's the part of the rep the dumbbell version tends to rush.