Technique
Conventional or sumo: choosing a deadlift stance
The two stances load the body differently enough that they are best thought of as separate lifts, and which suits you is largely a question of your skeleton.
The sumo-versus-conventional argument occasionally acquires a moral dimension, with sumo described as cheating because the bar travels a shorter distance. That framing is not useful — the two lifts distribute load differently and each is harder in its own way.
The mechanical differences
Conventional: feet roughly hip width, hands outside the legs, more forward torso lean, more hip flexion. Greater demand on the lower back, hamstrings and glutes. Longer bar path.
Sumo: wide stance, hands inside the legs, more upright torso, more knee flexion and hip abduction. Greater demand on the quadriceps, adductors and hip abductors. Shorter bar path, but a considerably harder start position.
Sumo does involve a shorter range — typically in the region of a fifth less bar travel. It also has a much harder position off the floor, because the hips are lower and the leverage at the start is worse. The two effects partly cancel, which is why plenty of lifters pull similar numbers with either.
Which suits you
Largely a matter of proportions and hip structure.
Conventional tends to suit people with relatively long arms, a shorter torso relative to their legs, and strong hips and lower back. Long arms reduce the distance the bar must travel and improve the starting position.
Sumo tends to suit people with shorter arms, longer torsos, and hips that comfortably allow a wide, externally rotated stance. Hip structure genuinely matters — some people's hips do not allow a comfortable wide stance at all, and forcing it produces groin pain.
These are tendencies rather than rules, and there are strong lifters at every proportion using both.
How to find out
Train both for a few months. Not a session each — a proper block, because sumo in particular is technically demanding and most people are terrible at it for the first several weeks.
The common mistake is trying sumo once, finding it feels awkward and weak, and concluding it does not suit you. It feels awkward because it is unfamiliar. Give it eight to twelve weeks of consistent practice before judging.
Sumo technique points
Stance width is individual. Start with feet somewhere around where a wide squat feels comfortable and adjust. Extremely wide stances are used by some competitors and require considerable hip mobility.
Toes turned out substantially, and the knees must track over them. Knees caving in is the most common sumo fault.
Push the knees out and open the hips as you set up. The feeling should be of spreading the floor.
Get the hips as close to the bar as you can while keeping the shins vertical or near it, with the chest up and the arms hanging straight down.
Take the slack out and engage the lats before pulling — the wedge position you create before the bar moves is more important in sumo than in conventional, because the start is the hardest part.
Then push the floor away with the legs. Sumo is more of a leg press than a pull, and lifters who try to yank it with their back stall at the floor.
Conventional technique points
Covered in more detail elsewhere. The essentials: bar over the midfoot, shins close, shoulders slightly ahead of the bar, hips at the height where the bar leaves the floor without them rising first, lats engaged, slack pulled out, and the bar dragging up the legs.
Training both
Useful even if you only compete with one. The other becomes an accessory that addresses different weaknesses.
A conventional puller who trains sumo builds quadriceps and hip abduction strength and improves off-the-floor position. A sumo puller who trains conventional builds lower back and hamstring capacity.
Common structure: the competition stance as the main lift, the other as a secondary movement at lower intensity, or as the emphasis in an off-season block.
The trap bar, briefly
Worth mentioning as a third option. The handles at the sides remove the need for the bar to travel around the knees, allowing a more upright torso and a more knee-dominant pattern.
Easier to learn, kinder to the lower back, and excellent for general strength and for athletes. Less specific to competitive powerlifting, and a completely legitimate main hinge for anyone not competing.
The honest summary
Pick the one your body does well, train it, and use the other as an accessory. The style argument is a distraction — the strongest deadlifters in the world use both, and the ones who plateau are usually the ones who spent two years arguing about which was legitimate rather than pulling.
