Bulgarian Split Squats vs Lunges: Which Single-Leg Exercise Builds the Most Muscle?

Bulgarian split squat vs lunges is a debate with a boring but useful answer: no study has shown that one of them builds clearly more muscle than the other. Both load the quads and glutes hard, and the “best” one is the version you can load progressively, week after week, without your knee or your balance getting in the way.

This guide compares the three single-leg staples most people argue about (Bulgarian split squats, walking lunges and deficit reverse lunges), then shows how torso lean, step length and equipment change what you feel. It sits inside our complete lower body and core training guide, so it stays focused on the exercises themselves.

Do single-leg exercises build as much muscle as squats?

Probably, yes. A 2025 systematic review and meta-analysis (Kassiano et al., 2025) pooled 9 studies and found no significant difference in muscle hypertrophy between unilateral and bilateral training. Strength followed specificity: bilateral training improved bilateral strength more, while unilateral training improved single-leg strength more.

Two cautions. The authors described the literature as limited, and the included studies carried moderate risk of bias. So the honest reading is “no evidence of a difference”, not “proven identical”.

For a deeper look at when each makes sense, see our article on unilateral vs bilateral training for hypertrophy. The short version is that single-leg work is a good swap when you want less spinal loading or want to expose left-right differences, and a fair addition rather than a replacement for squatting.

Bulgarian split squat: what makes it different?

The back foot is on a bench, the front foot does most of the work, and the range of motion is long. A 2021 study of 20 resistance-trained men (Mackey & Riemann, 2021) compared it with the back squat. The split squat was done at 35% of back squat 1RM, the back squat at 70%. Both were hip-dominant, and the knee contributed relatively less in the split squat, with less knee bend at the bottom. The authors suggested it can suit situations where you want to emphasise hip extension while limiting knee demands, such as early knee rehab.

That fits what lifters report: you get a big stretch through the front hip and a lot of work on the glute and quad without needing a heavy barbell on your back. It does not prove the split squat grows more muscle, only that the loading profile is different.

Quads or glutes: how torso lean changes the split squat

This is the most useful adjustment you can make. In a cross-sectional EMG study of 21 trained female athletes (Aygun-Polat et al., 2025), flexing the trunk forward increased activation of the gluteus maximus, biceps femoris and rectus femoris compared with a neutral trunk. A suspension-trainer version mostly raised spinal erector activity.

That partly matches what coaches teach: hinge from the hips with a slight forward lean and the glutes and hamstrings join in. The common cue that staying tall shifts work onto the quads was not borne out here, since rectus femoris activity actually went up with the lean. An upright torso with the knee travelling forward is still a sensible quad-led setup, just not a proven one.

Remember this was a small study in one group, and EMG shows activity, not growth. Use it as a guide for how the set feels, not as a promise.

Foot position in practice

Put your front foot far enough forward that your heel stays flat at the bottom. Too close and the front knee crashes forward and your heel lifts. Too far and you run out of hip mobility and the set turns into a stretch you cannot control.

Test with two or three bodyweight reps. Adjust by a few centimetres, then lock that position in for the whole set so both sides are comparable.

Walking lunges: a quad and glute volume tool

Walking lunges are dynamic, which makes them handy for higher reps. The closest data come from forward lunges rather than true walking lunges. A 2025 EMG study of 20 adults at their 12-rep max (Escamilla et al., 2025) compared short vs long steps, and stepping out and back vs lunging with the feet stationary. Quadriceps, hamstring, adductor and glute max activity were greater with a long step than a short one, and glute max and glute medius activity were greater with a stride than without. The authors concluded that loaded forward lunges produced high to very high activity in the quads, glute max and glute medius, with moderate activity in the hamstrings, calves and adductor longus.

So a longer step and a real stride are the glute-friendly settings. Shorter steps lowered activity in most muscles measured, quads included, so they are the easier option rather than a quad-specific one. Again, EMG tells us about muscle activity, not guaranteed muscle size.

A systematic review of glute max activation during strength and hypertrophy exercises (Neto et al., 2020) also listed the split squat, in-line lunge and traditional lunge among exercises with very high glute max activation (above 60% of maximal voluntary contraction). For a wider glute comparison, see hip thrusts vs squats for glute growth.

Deficit reverse lunge: why lifters like it

The deficit reverse lunge puts your front foot on a low platform (a 2-5 cm plate is plenty to start) and steps the other leg back. The back knee gets lower than the front foot, which lengthens the front-leg hip and glute under load.

The reason that matters is range of motion. A systematic review of full vs partial range (Schoenfeld & Grgic, 2020) found that full-range training had beneficial effects on lower-body hypertrophy versus partial range. That review included six studies, mostly in men, so it supports “do not cut the bottom off your reps” rather than “deeper is always better”.

On knee safety, many lifters find the reverse lunge friendlier than the forward lunge because the shin stays more upright on the working leg. I could not find a controlled trial that confirms deficit reverse lunges are safer for knees, so please treat that as a practical coaching observation, not a proven effect.

Bulgarian split squat vs lunges vs deficit reverse lunge

Exercise	Typical strength	Common limiter	Simple emphasis dial
Bulgarian split squat	Loaded stretch, stable bench support	Balance, rear-foot comfort	Lean forward for more glute
Walking lunge	Dynamic reps, easy to chain sets	Space, grip, sloppy steps	Longer step for more glute
Deficit reverse lunge	Controlled path, long hip range	Platform setup, holding weights	Hinge forward for more glute

If you only pick one, pick the one you can add load or reps to every week for 6-8 weeks. Progress is what makes muscle, not the name of the exercise.

Dumbbells vs Smith machine for single-leg work

Free weights are the default because they are cheap and available everywhere. If balance limits your load, a Smith machine can help you push the legs harder.

An 8-week trial in 37 sport-science students (Marcos-Frutos et al., 2025) compared free-weight and Smith machine back squats and found comparable growth in vastus lateralis cross-sectional area. Strength gains were larger when the training and testing conditions matched. That trial used two-leg squats in students, not split squats, so the transfer to single-leg work is an assumption.

The practical read: a Smith machine split squat is a fair option, especially if wobbling on dumbbells is what ends your set early.

Embracing the burn without wrecking your knees

Split squats feel awful, and that is normal: a lot of tension, a long range, one leg doing the work. A strong burn in the thigh or glute is fine. Sharp pain at the front of the knee, pain that lingers afterward or a knee that gives way is not.

Stop the set if that happens, simplify the exercise (shorter range, lighter weight, a different variation) and see a physiotherapist or doctor if it persists. This article is general education, not a diagnosis.

How to program unilateral leg work

Treat single-leg movements as part of your weekly leg volume, not as an add-on. A simple template for most lifters:

• One heavy bilateral lift (squat or leg press) first.
• One single-leg movement second, 2-3 hard sets per leg.
• Start with the weaker leg and match the reps on the stronger side.
• Use the same dumbbell weight on both sides and only add weight when the weaker side can do it.

For squat variation specifics, see our high-bar vs low-bar squat guide. To place these exercises in a full week, use the complete leg workout programming guide and check weekly hard sets with the training volume calculator. Our free leg day plan is also a good starting point.

On a vegetarian Indian diet, getting enough protein (dal, paneer, curd, soya) matters more for leg growth than which lunge variation you choose, so make sure the basics are covered first.

Bottom line

Bulgarian split squats, walking lunges and deficit reverse lunges can all build leg muscle. The evidence does not crown a winner, so choose the exercise you can load safely and progress consistently. Use torso lean and step length to steer the emphasis, keep your range of motion full, and judge the set by how well you control it, not by how much it hurts.