The biceps and triceps stabilize the elbow joint during deadlifts, but you don’t need monster guns to pull heavy weights because the arms aren’t the primary movers. Below I analyze the functions of the biceps and triceps in a deadlift.
When you deadlift heavy weights, the bar has to be kept as close as possible to your body. The closer the bar is to you, the less stress there is on the lower back. When the bar is too far away, you can’t deadlift as heavy due to the long lever.
The main muscles that keep the bar close to your body are the long head of the triceps and the latissimus dorsi. When your triceps are tired, you can expect to lose some efficiency.
Another very important role of the triceps is keeping your elbows straight. When you deadlift with flexed elbows, you place the biceps at a compromised position. It is literally impossible to pull super heavy weights with curled arms.
Flexed elbows in a combination with the mixed grip have caused many biceps tears during heavy deadlift attempts. That’s why some lifters actively flex their triceps before the lift. You can’t have bent arms when your triceps are fully flexed.
Note: If you are afraid of biceps tears, use a hook grip or straps.
If you’re deadlifting with good form, your numbers should not be limited by biceps strength. Nobody has a weak deadlift because his biceps are not big or exceptionally strong. I’ve seen plenty of people deadlift heavy weights with chicken arms, myself included.
However, you still don’t want to be deadlifting with fatigued biceps. That’s why I never do pull-ups or other exercises that hit the arms before deadlifts.
Moreover, biceps weakness often results in forearm weakness.
The main function of the biceps during deadlifts is to stabilize the elbow joint.
Does this mean that the deadlift will make my arms huge?
Not really. The fact that a muscle is involved in an exercise does not mean that hypertrophy will take place. If your goal is to have bigger arms, it’s better to invest in heavy pull-ups, biceps curls, weighted dips, close grip bench presses and other movements which use the biceps and triceps as primary movers over a large range of motion.
Isometrics and exercises where the arms are simply stabilizers can be helpful, but they cannot beat dedicated movements. Finding a decent deadlifter with small arms is easy, but locating a decent bench presser or dipper with puny arms requires a more extensive research. It’s like looking for a heavy squatter with underdeveloped hips and/or legs. At least one of the two will be big, depending on the squat style used by the individual.
Which style uses the arms more – conventional or sumo?
Technically, the conventional style requires more triceps activation because your hips are further away from the bar, but this is of little importance since your arms are never the limiting factor in either of the cases.
Unlike your arms, the forearms have to fight hard during deadlifts. The deadlift can develop a very strong grip, but you should know that a strong grip does not always come with Popeye forearms. If you want big forearms, the deadlift is not the best option because the wrist is not moving.