For most people, holding the weight in the hand opposite the standing leg (the contralateral hand) is the stronger default choice for a single-leg Romanian deadlift. Research on muscle activation during the exercise shows that contralateral loading produces meaningfully greater activity in the glutes, especially the upper portion, and in the spinal erectors on the working side. That said, same-side (ipsilateral) loading is not wrong. It simply shifts the challenge in a different direction, and there are good reasons to use it deliberately.
What Contralateral Loading Actually Does
When you stand on your right leg and hold a dumbbell or kettlebell in your left hand, the weight creates a rotational pull that wants to spin your torso toward the loaded side and shift your center of mass away from the stance foot. Your body has to fight that rotation, and the muscles responsible for that fight are the glute medius and the deep hip stabilizers on the standing-leg side, along with the erector spinae muscles running up that side of the spine. A 2023 study measuring muscle electrical activity during single-leg RDLs found a moderate-to-large increase in gluteus medius, erector spinae, and both upper and lower gluteus maximus activation when subjects switched from ipsilateral to contralateral loading. The upper gluteus maximus showed the biggest jump, with activity levels well above what’s typically seen during bilateral hip-hinge exercises.1PubMed Central. Effects of loading positions on the activation of trunk and hip muscles during flywheel and dumbbell single-leg Romanian deadlift exercises
The reason is straightforward. The opposite-side load creates a longer moment arm around your stance hip. Your hip abductors and rotators have to produce more force to keep the pelvis level and prevent it from dropping or twisting. If your main goal with the single-leg RDL is training the glute medius (a common priority for runners, athletes, and anyone rehabbing knee or hip issues), contralateral loading gets you there faster with less total weight.
When Same-Side Loading Makes More Sense
Ipsilateral loading, where you hold the weight on the same side as the stance leg, does not produce the same anti-rotation demand. The load sits closer to the stance hip, so the rotational torque is smaller. That means your glute medius and spinal erectors don’t have to work as hard to keep you square. But the hamstrings and the lower portion of the gluteus maximus still fire at comparable levels, because the hip-hinge pattern itself hasn’t changed, just the frontal-plane challenge layered on top of it.
This makes ipsilateral loading a useful option in a few situations. If you’re a beginner learning the single-leg RDL, same-side loading is generally easier to balance. The center of gravity stays closer to the base of support, so you can focus on the hip hinge and hamstring stretch without toppling sideways. It also allows you to handle slightly more weight, because balance is less of a limiting factor. For someone chasing raw hamstring and posterior-chain loading and less concerned about hip-stabilizer work, ipsilateral holds are a valid tool.
People recovering from ankle sprains or dealing with poor balance on one side sometimes benefit from starting ipsilateral and progressing to contralateral as their stability improves. The exercise is still challenging in this configuration; it simply doesn’t layer as much lateral and rotational demand on top of the hinge.
How the Posterior Oblique Sling Plays In
One of the less obvious reasons contralateral loading feels so effective is that it lines up with the way your body naturally transfers force during walking, running, and throwing. The posterior oblique sling is a fascial chain connecting the gluteus maximus on one side of the body to the latissimus dorsi on the opposite side, linked through the thoracolumbar fascia in your lower back. This diagonal system delivers force across the center of the body and stabilizes the lumbar spine and pelvis during single-leg activities.2PubMed Central. Influence of muscle activation of posterior oblique sling from changes in activation of gluteus maximus from exercise of prone hip extension of normal adult male and female
When you hold a weight in the hand opposite the stance leg, you load that sling almost exactly the way it functions in real movement. Your right glute max has to fire hard to extend the hip while your left lat and the fascia between them stabilize the trunk. This is essentially an exaggerated version of what happens during the push-off phase of a sprint stride, which is why single-leg RDLs with contralateral loading show up so frequently in athletic training programs. It’s not just an isolation exercise for the glutes; it’s a coordination drill for the whole diagonal chain from shoulder to opposite hip.
Dumbbell vs. Kettlebell vs. Flywheel
The 2023 loading-position study also compared flywheel-resisted single-leg RDLs to standard dumbbell versions and found no significant difference in muscle activation between the two types of resistance for any of the muscles tested.1PubMed Central. Effects of loading positions on the activation of trunk and hip muscles during flywheel and dumbbell single-leg Romanian deadlift exercises What mattered was where the load was placed (ipsilateral vs. contralateral), not how the resistance was generated. That’s a useful finding, because it suggests the loading-position principle transfers across equipment. Whether you’re using a kettlebell, a dumbbell, a cable machine, or anything else that puts resistance in one hand, the same logic applies: opposite hand equals more anti-rotation demand and greater glute medius activation.
Kettlebells are the most popular choice for this exercise, largely because the handle design lets the weight hang naturally below the fist without wrist strain. Dumbbells work fine but can feel awkward at heavier loads because the plates extend outward and can bump into the stance leg during the descent. A cable set at a low pulley angle is another option that some people find smoother for progressive overload, since you can adjust resistance in smaller increments than jumping to the next dumbbell size.
What About Holding a Weight in Each Hand?
Plenty of people perform single-leg RDLs with a dumbbell in both hands. This is essentially a compromise between ipsilateral and contralateral loading. The rotational demands partially cancel out because the load is balanced on both sides of the body. The exercise still trains the hip hinge on one leg, the hamstrings still work hard, and the glute max still fires to extend the hip. But you lose most of the anti-rotation benefit that makes the single-arm versions special.
Two-handed loading is a reasonable choice when the goal is simply to overload the posterior chain on one leg at a time, particularly if you’re using the single-leg RDL as a heavy accessory lift after squats or conventional deadlifts. It lets you handle more total weight without balance becoming the weak link. But if hip-stabilizer training is a priority, or if you’re using the exercise to address a known asymmetry in glute medius strength, one dumbbell in the contralateral hand will do more per pound of load than two dumbbells splitting the weight evenly.
Common Mistakes That Undermine Your Loading Choice
The loading position only matters if your form actually lets the intended muscles do their job. A few errors are common enough that they can completely negate the benefits of contralateral loading.
- Opening the hips: Many people let the free leg drift outward as they hinge, rotating the pelvis so the hip of the trailing leg faces the ceiling. This turns the movement into a rotated hip hinge instead of a clean sagittal-plane hinge with frontal-plane stabilization. The fix is to think about pointing the toes of the trailing foot straight down throughout the movement, which cues the pelvis to stay square.
- Reaching the weight to the floor: The single-leg RDL is a hip hinge, not a touch-the-ground drill. If you’re rounding your lower back to get the dumbbell to the floor, the range of motion has exceeded your hamstring flexibility. Stop at the point where you feel a strong stretch in the hamstrings of the standing leg and your back is still flat. Depth will increase naturally over weeks.
- Shrugging the loaded shoulder: When the weight pulls the arm downward, some people hike the shoulder up to compensate. This tenses the upper trap and takes tension off the lat and thoracolumbar fascia, which disrupts the posterior oblique sling engagement that makes contralateral loading valuable. Let the loaded arm hang relaxed, like a plumb line from the shoulder.
- Looking up: Craning the neck up to watch yourself in a mirror shifts your center of mass forward and hyperextends the cervical spine. Keep your gaze following the floor a few feet in front of you so your head stays in line with your torso throughout the hinge.
Grip strength can also become an unexpected bottleneck. Because the single-leg RDL is a slow, controlled movement, the weight hangs in your hand for the entire set without the momentum assistance you’d get in a clean or a swing. If your grip gives out before your glutes and hamstrings are challenged, consider using lifting straps or switching to a kettlebell with a thicker handle that distributes the load across more of the palm.
Programming the Exercise for Different Goals
How you load the single-leg RDL should follow from what you’re trying to improve. A few common scenarios play out differently.
For runners and field-sport athletes trying to build single-leg stability and reduce injury risk, contralateral loading with moderate weight in the 8-to-12-rep range is the most common prescription. The goal is to train the glute medius and the anti-rotation system under controlled conditions that mimic the demands of sprinting and cutting. Going too heavy here often backfires, because balance breaks down and you compensate by twisting the trunk, defeating the purpose.
For lifters using the single-leg RDL as a posterior-chain hypertrophy accessory, two dumbbells or a heavy single dumbbell on the ipsilateral side can work well. The priority is time under tension for the hamstrings and glute max, not hip-stabilizer training. Sets of 6 to 10 with a deliberate eccentric (lowering phase) of about 3 seconds are common. Contralateral loading still works here, but you’ll likely need to use a lighter weight, meaning total mechanical tension on the hamstrings is lower.
For people rehabbing after an ACL reconstruction or dealing with chronic hip instability, physical therapists often start with bodyweight single-leg RDLs, then progress to light contralateral loading. The reason is that poor gluteus medius activation is a well-documented issue after knee injuries, and the contralateral hold specifically targets that muscle. Starting too heavy or using ipsilateral loading in this context may let the patient complete the movement without ever meaningfully activating the muscle that needs the most work.
The Muscle Activation Numbers in Context
The 2023 study reported that during single-leg RDLs, the upper gluteus maximus reached activity levels between roughly 105% and 169% of a maximum voluntary contraction reference, while the biceps femoris (the main hamstring muscle) ranged from about 70% to 122%.1PubMed Central. Effects of loading positions on the activation of trunk and hip muscles during flywheel and dumbbell single-leg Romanian deadlift exercises Those are high numbers. Values above 100% of a reference contraction aren’t unusual in EMG research (the reference test doesn’t always capture true maximal output), but they confirm that the single-leg RDL is a genuinely demanding exercise for both the glutes and hamstrings regardless of loading position. The contralateral vs. ipsilateral distinction matters for where the extra activation shows up, particularly in the gluteus medius and erector spinae, not for whether the exercise is effective in the first place.
This is worth keeping in mind if you find yourself overthinking the loading question. Both versions work. Both produce high levels of muscle activity in the primary movers. The contralateral version simply adds a layer of hip-stabilizer and anti-rotation demand that the ipsilateral version mostly skips. If you’re not sure which to pick, default to contralateral. If you find that your balance is so challenged that you can barely complete a set without putting your foot down, switch to ipsilateral until your stability improves, then revisit contralateral loading in a few weeks.
Switching Hands Between Sets
One underused strategy is alternating loading positions within the same session. Perform your first working set or two with the weight in the contralateral hand, where the stabilizer demand is highest and your nervous system is freshest. Then switch to ipsilateral loading for a final set or two, which lets you bump the weight up slightly and push the hamstrings and glute max harder now that the stabilizers are already fatigued. This approach borrows from the general programming principle of moving from coordination-heavy exercises to load-heavy exercises within a session. You get the anti-rotation training early when your balance and focus are sharp, and you get the raw posterior-chain stimulus later when mechanical overload matters more than stabilization quality.
Another variation is to hold the weight in the contralateral hand for one leg and the ipsilateral hand for the other, deliberately creating a different training stimulus for each side. This sounds unusual, but it can make sense if you have a known asymmetry: for example, a left glute medius that tests weaker on single-leg balance assessments. You’d load contralateral for the left-leg-stance sets (to push that weak glute medius harder) and ipsilateral for the right-leg-stance sets (where the medius doesn’t need as much extra work). Over time, the goal is to close the gap and return to symmetric loading.