Although the kettlebell swing is great for firming and shaping the arms, they don’t do the main work of lifting the kettlebell. The arms are relaxed, straight or slightly bent during the swings. Lift the kettlebell with a pop through your hips, not your arms. Your arms, forearms and hands will get plenty of exercise just guiding the weight, especially as it drops. No muscle group should feel any specific strain; your muscles groups should be working together.
