- Grasp a barbell at around shoulder width apart using an underhand grip (palms facing up).
- Stand straight up, feet together (you may be more comfortable putting one foot back for stability), back straight, and with your arms fully extended.
- The bar should not be touching your body.
- Keeping your eyes facing forwards, elbows tucked in at your sides, and your body completely still, slowly curl the bar up.
- Squeeze your biceps hard at the top of the movement, and then slowly lower it back to the starting position.
- Repeat for desired reps.
Changing grip width will affect what muscle of your biceps works the most. Taking a wide grip on the barbell increases the tension on the short (inner) head of the biceps. While a narrow grip will focus more on the long (outer) head.