Your Basic Trainer

Library / Exercises

Split squat

Also called Bulgarian split squat, Bulgarian squat, rear-foot-elevated split squat, rear-leg-elevated split squat, rear-elevated split squat, stationary split squat, RFESS

A squat with the feet fixed in a stride, often with the rear foot raised on a bench. What studies measured at the hip, knee and thigh muscles, how each leg shares the work, and what short training trials found.

Region
Hip
Muscles
quadriceps, gluteus maximus, hamstrings, gluteus medius, hip flexors, gastrocnemius, soleus
Updated
October 7, 2026
Reviewed
October 7, 2026 · how entries are checked

Movement

In the split squat, both feet stay fixed to the ground, one in front of the other1. The authors of one study describe it as moving much like the forward walking lunge1. The major difference they name is impact force, the force on the body at the moment it meets the ground1. The walking lunge has it at each landing, and the split squat does not1.

In the Bulgarian split squat, the rear leg is raised on a bench6. The authors of one biomechanics study say this sets it apart from other split-squat variations, because the bench leaves the hip more extended6. Studies on this page also use the names rear-foot-elevated split squat and Bulgarian squat2,7. Each finding below keeps the name its study used. The single-leg squat page covers a loaded variation that studies call the modified single-leg squat8.

How far it is a one-leg exercise

In 26 recreationally trained men doing the rear-foot-elevated split squat, the lead foot produced a mean 84.36% of total vertical force2. The link between force under the rear foot and exercise intensity was trivial and not significant2. The authors concluded that their data give no sign of the rear foot adding to the forces the exercise demands2.

What a longer step changes

Twenty male college students did barbell split squats with steps from 50% to 120% of leg length4. They lifted their 10-repetition-maximum load, the heaviest they could lift ten times4. Going from the shortest step to the longest raised the front leg’s peak hip extension moment by 15.7%4. Hip extension is moving the thigh backward at the hip, or straightening the body at the hip. The longer step lowered the front leg’s peak moment for knee extension, straightening the knee, by 15.1%4.

What it loads

Twenty resistance-trained males did the back squat at 70% of their one-repetition maximum, the heaviest load they could lift once3. They did the Bulgarian split squat at 35% of that back squat maximum3. In both squats, the peak joint moment at the hip was significantly greater than at the knee or the ankle3.

The hip and knee, against the back squat

Three studies set the split squat’s joint demands beside the back squat’s3,9,10:

  • The same 20 resistance-trained males. In the Bulgarian split squat, the peak moment at the knee was lower than the ankle’s3. Peak knee joint displacement was significantly less than in the back squat3.
  • Eight male college rugby players at their 10-repetition-maximum load in each exercise. At the bottom position, the rear-foot-elevated split squat gave a 44% greater hip extension moment than the two-leg back squat9.
  • A modelling study, which estimates forces with a model rather than measuring them directly, with added loads of 0 to 75% of body mass. It worked out the relative effort of the hip extensors, the muscles that move the thigh backward at the hip10. That effort increased disproportionately more in the split squat at the 50% and 75% loads10. Knee extensor effort did not differ between the exercises10.

Front-leg muscles

The quadriceps, the four muscles on the front of the thigh, extend the leg at the knee11. The gluteus maximus, the large muscle of the buttock, extends the hip12. The hamstrings, three long muscles at the back of the thigh, extend the hip and flex the knee11,13. Studies also name single muscles: the vastus lateralis and rectus femoris are quadriceps muscles, and the biceps femoris is a hamstring.

A systematic review, which searches for the research on a question in a set, checkable way, covered 16 electromyography studies14. Electromyography (EMG) measures a muscle’s activity by picking up its electrical signals. The review classed the split squat among the exercises with a very high level of gluteus maximus activation14. Very high meant above 60% of maximal voluntary isometric contraction, a muscle’s hardest effort while the joint stays still14.

One EMG study set the split squat, the rear-foot-elevated split squat and the single-leg squat side by side15. Eleven healthy, moderately strength-trained subjects did a 6 to 8 repetition maximum set of each15. Peak gluteus maximus and vastus lateralis activity did not differ significantly between the exercises15. Biceps femoris activity was higher in the rear-foot-elevated split squat than in the split squat15. The figures were 76.1% against 62.3% of maximal voluntary isometric contraction15.

The gluteus medius is a buttock muscle that lies beneath the gluteus maximus. In the same subjects, its activation was significantly higher in the single-leg squat than in either split squat15.

Gluteus medius activation, % of maximal voluntary isometric contractionSingle-leg squat81.9 Rear-foot-elevated split squat54.9 Split squat46.2
Gluteus medius activation, % of maximal voluntary isometric contraction. Bars start at zero; the table below gives each value with its source.
ExerciseGluteus medius activation, % of maximal voluntary isometric contraction
Single-leg squat81.915
Rear-foot-elevated split squat54.915
Split squat46.215

Two more EMG studies changed one thing each4,16:

  • Step length, in 20 male college students. The authors concluded that a longer step activated the hip extensors more and had a limited effect on the knee extensors4.
  • Trunk position, in 21 trained female athletes. In the Bulgarian split squat, a flexed trunk increased gluteus maximus, biceps femoris and rectus femoris activation compared with a neutral trunk16.

Against the hip thrust

Two studies compared the split squat with the hip thrust, which lifts the hips with the upper back on a bench17,18. In twelve male team sport athletes at a three-repetition-maximum load, peak gluteus maximus activity was higher in the barbell hip thrust17. The second study had 20 young adult women with intermediate resistance-training experience lift 80% of their one-repetition maximum18. Gluteus maximus, vastus lateralis and hamstring activity was highest in the bottom third of the rear-foot-elevated split squat18. In the hip thrust it was highest at the top18.

The rear leg

Two modelling studies found high quadriceps forces in the rear leg19,20. In a simulation study in which 11 participants did split squats, the rectus femoris showed its greatest loading in the rear limb19. In an eight-participant study with an emphasis on females, quadriceps forces were also high in the back leg of the split squat20. The rectus femoris is also one of the hip flexors, the muscles that bend the hip: it helps flex the thigh on the pelvis21. In the simulation study, the gluteus maximus was almost inactive in the rear limb19.

A study of nine trained men doing bodyweight Bulgarian split squats looked at the rear hip6. It extended about 10° further when the men reduced their forward trunk lean than when they added lean6. The same study measured a moment from the rear leg that acted against the front leg’s hip extensors6. In a wide stance, it made up 70 to 97% of the total external resistance on those muscles6. In a narrow stance, this moment rose significantly when the trunk was more upright6.

How the body adapts

Three trials that used random assignment trained the Bulgarian or rear-foot-elevated split squat for five or six weeks5,22,23.

Trained against the back squat

Eighteen academy rugby players were randomly assigned to train twice a week for 5 weeks with the rear-elevated split squat or the back squat5. One-repetition maximum in both lifts improved over time, with no significant group-by-time interaction5. Performance in the 40-metre sprint and the pro-agility test also improved, with no significant differences between the groups5. The 10-metre sprint did not improve5.

Twenty-three elite youth soccer players were randomly assigned to 6 weeks of twice-weekly training22. One group did rear-foot-elevated split squats and single-leg jumps, and the other did back squats and two-leg jumps22. There were no between-group differences in physical performance measures22. The split squat group improved that lift by 33.29%22. The back squat group improved back squat strength by 26.01% and rear-foot-elevated split squat strength by 23.34%22.

One leg against two, pooled

Two reviews pooled trials of unilateral training, on one side of the body, against bilateral training, on both24,25. Each was a meta-analysis, a study that pools the results of several earlier studies. They agree on bilateral strength and differ on unilateral strength, which the specificity page also covers24,25:

  • A 2022 meta-analysis of 14 studies, with 392 subjects aged 16 to 26. Bilateral training improved bilateral strength more24. For unilateral strength, it found no significant difference between the two kinds of training24.
  • A meta-analysis of 9 studies. Bilateral training increased bilateral strength more, and unilateral training increased unilateral strength more, with a moderate risk of bias overall25. It found no significant difference in hypertrophy, growth in the size of a muscle, and its authors describe the literature as limited25.

Strength and muscle thickness

In a randomised within-subject trial, 24 resistance-trained men did Bulgarian split squats at 80% of one-repetition maximum, for 4 sets of 1023. After 18 sessions over 6 weeks, their Bulgarian split squat one-repetition maximum had risen by 13.0%23. Vastus lateralis thickness had risen by 9.3%23.

Progressive overload

The progressive overload page covers the principle. For the split squat, the studies here set load in three ways5,9,23:

  • A progressive increase over months. Eight male college rugby players trained the rear-foot-elevated split squat for 4 months with a progressive increase in loads, before their 10-repetition-maximum testing9.
  • A percentage of each lift’s own maximum. In the 5-week rugby trial, each group trained at a relative percentage of the one-repetition maximum of the lift it used5.
  • A percentage of the starting maximum. The 6-week trial of 24 men had three supervised sessions a week and prescribed loads relative to the baseline one-repetition maximum23. Its authors report that they kept no systematic record of the load lifted at each session23.

Heavy load against light load with a cuff

That 6-week trial compared two legs of the same men23. One leg trained at 80% of one-repetition maximum23. The other trained at 30% with blood flow restriction, a cuff around the limb that partly limits its blood flow23. There was no significant condition-by-time interaction for strength, vastus lateralis thickness or single-leg jump measures23.

What added load does to muscle forces

Nine healthy subjects did the squat, the split squat and the step-up with added loads of 0 to 75% of body mass26. Estimated forces in the gluteus maximus, gluteus medius, hamstrings and the vasti of the quadriceps increased with load in each exercise26. So did forces in two calf muscles, the gastrocnemius and soleus26. For the gluteus maximus and vasti, the rise with load was often more pronounced in the split squat and step-up than in the squat26.

Connections

Modelled forces rose with load in the vasti of the quadriceps, the gluteus maximus, the gluteus medius and the hamstrings26. They also rose in the gastrocnemius and soleus26. In the rear leg, a simulation study found the rectus femoris, one of the hip flexors, at its greatest loading19,21. One study measured joint moments at the hip and knee3.

Related exercise pages: lunge, step-up, back squat, hip thrust and single-leg squat1,3,15,17,26. Related principle and method pages: progressive overload, specificity and blood flow restriction training9,23,25.

Split squat loads

Sources

  1. Stastny P, Lehnert M, Zaatar AM, Svoboda Z, Xaverova Z (2015). Does the Dumbbell-Carrying Position Change the Muscle Activity in Split Squats and Walking Lunges?. Journal of strength and conditioning research. doi:10.1519/JSC.0000000000000976 PMID 25968228
  2. Helme M, Emmonds S, Low C (2020). Is the Rear Foot Elevated Split Squat Unilateral? An Investigation Into the Kinetic and Kinematic Demands.. Journal of strength and conditioning research. doi:10.1519/JSC.0000000000003727 PMID 32796420
  3. Mackey ER, Riemann BL (2021). Biomechanical Differences Between the Bulgarian Split-Squat and Back Squat.. International journal of exercise science. doi:10.70252/CIYT8956 PMID 34055144
  4. Song Q, Ma M, Liu H, Wei X, Chen X (2023). Effects of step lengths on biomechanical characteristics of lower extremity during split squat movement.. Frontiers in bioengineering and biotechnology. doi:10.3389/fbioe.2023.1277493 PMID 38026855
  5. Speirs DE, Bennett MA, Finn CV, Turner AP (2016). Unilateral vs. Bilateral Squat Training for Strength, Sprints, and Agility in Academy Rugby Players.. Journal of strength and conditioning research. doi:10.1519/JSC.0000000000001096 PMID 26200193
  6. Arakawa H, Nakashima H, Li X, Tanimoto M (2025). Rear Leg-derived Moment Contributes to Resistance Against Hip Extension in Bulgarian Split Squats.. International journal of exercise science. doi:10.70252/NEXQ5666 PMID 40909869
  7. Andersen V, Fimland MS, Brennset O, Haslestad LR, Lundteigen MS, Skalleberg K, Saeterbakken AH (2014). Muscle activation and strength in squat and Bulgarian squat on stable and unstable surface.. International journal of sports medicine. doi:10.1055/s-0034-1382016 PMID 25254898
  8. McCurdy K, O'Kelley E, Kutz M, Langford G, Ernest J, Torres M (2010). Comparison of lower extremity EMG between the 2-leg squat and modified single-leg squat in female athletes.. Journal of Sport Rehabilitation. doi:10.1123/jsr.19.1.57 PMID 20231745
  9. Arakawa H, Mori M, Tanimoto M (2023). Greater Hip Moments in Rear-Foot-Elevated Split Squats Than in Conventional Back Squats With the Same Relative Intensity of Loads.. Journal of strength and conditioning research. doi:10.1519/JSC.0000000000004351 PMID 36542838
  10. Wolf WI, Kim H, Kipp K (2021). Musculoskeletal modelling based estimates of load dependent relative muscular effort during resistance training exercises.. Sports biomechanics. doi:10.1080/14763141.2021.1983636 PMID 34633906
  11. Betts JG, Young KA, Wise JA, Johnson E, Poe B, Kruse DH, Korol O, Johnson JE, Womble M, DeSaix P (2022). Anatomy and Physiology 2e. OpenStax. Link
  12. Pourahmadi M, Asadi M, Dommerholt J, Yeganeh A (2020). Changes in the macroscopic morphology of hip muscles in low back pain.. Journal of Anatomy. doi:10.1111/joa.13086 PMID 31475359
  13. Obey MR, Broski SM, Spinner RJ, Collins MS, Krych AJ (2016). Anatomy of the Adductor Magnus Origin. Orthopaedic Journal of Sports Medicine. doi:10.1177/2325967115625055 PMID 26798764
  14. Neto WK, Soares EG, Vieira TL, Aguiar R, Chola TA, Sampaio VL, Gama EF (2020). Gluteus Maximus Activation during Common Strength and Hypertrophy Exercises: A Systematic Review.. Journal of sports science & medicine. PMID 32132843
  15. Mausehund L, Skard AE, Krosshaug T (2019). Muscle Activation in Unilateral Barbell Exercises: Implications for Strength Training and Rehabilitation.. Journal of strength and conditioning research. doi:10.1519/JSC.0000000000002617 PMID 29870422
  16. Aygun-Polat E, Guzel NA, Guruhan S, Polat Y, Karatas N (2025). Targeted muscle activation in Bulgarian split squat variations: effects of trunk position and suspension-based execution.. BMC sports science, medicine & rehabilitation. doi:10.1186/s13102-025-01306-z PMID 40867012
  17. Williams MJ, Gibson NV, Sorbie GG, Ugbolue UC, Brouner J, Easton C (2021). Activation of the Gluteus Maximus During Performance of the Back Squat, Split Squat, and Barbell Hip Thrust and the Relationship With Maximal Sprinting.. Journal of strength and conditioning research. doi:10.1519/JSC.0000000000002651 PMID 33332802
  18. McCurdy K, Walker J, Kelly C, Polinski M (2021). Hip and Knee Extensor Activation During the Hip Thrust and Rear-Foot-Elevated Split Squat in Trained Females.. Journal of strength and conditioning research. doi:10.1519/JSC.0000000000004035 PMID 33900255
  19. Schellenberg F, Taylor WR, Lorenzetti S (2017). Towards evidence based strength training: a comparison of muscle forces during deadlifts, goodmornings and split squats.. BMC sports science, medicine & rehabilitation. doi:10.1186/s13102-017-0077-x PMID 28725437
  20. Jaeggi JS, Achermann B, Lorenzetti SR (2024). Female Lower Body Muscle Forces: A Musculoskeletal Modeling Comparison of Back Squats, Split Squats and Good Mornings.. Journal of functional morphology and kinesiology. doi:10.3390/jfmk9020068 PMID 38651426
  21. Gray H; Lewis WH (editor) (1918). Anatomy of the Human Body. Lea & Febiger, Philadelphia (20th edition). Link
  22. Stern D, Gonzalo-Skok O, Loturco I, Turner A, Bishop C (2020). A Comparison of Bilateral vs. Unilateral-Biased Strength and Power Training Interventions on Measures of Physical Performance in Elite Youth Soccer Players.. Journal of strength and conditioning research. doi:10.1519/JSC.0000000000003659 PMID 32541618
  23. Wang Y, Zhao X, Zhang L, Gao X, Zheng Z, Wang S (2026). Unilateral low-load blood flow restriction vs. high-load training in the Bulgarian split squat: a randomized within-subject design on strength, hypertrophy, and asymmetry.. Frontiers in physiology. doi:10.3389/fphys.2026.1786733 PMID 41983008
  24. Liao KF, Nassis GP, Bishop C, Yang W, Bian C, Li YM (2022). Effects of unilateral vs. bilateral resistance training interventions on measures of strength, jump, linear and change of direction speed: a systematic review and meta-analysis.. Biology of sport. doi:10.5114/biolsport.2022.107024 PMID 35959319
  25. Kassiano W, Nunes JP, Costa B, Ribeiro AS, Loenneke JP, Cyrino ES (2025). Comparison of Muscle Growth and Dynamic Strength Adaptations Induced by Unilateral and Bilateral Resistance Training: A Systematic Review and Meta-analysis.. Sports medicine (Auckland, N.Z.). doi:10.1007/s40279-024-02169-z PMID 39794667
  26. Kipp K, Kim H, Wolf WI (2020). Muscle Forces During the Squat, Split Squat, and Step-Up Across a Range of External Loads in College-Aged Men.. Journal of Strength and Conditioning Research. doi:10.1519/JSC.0000000000003688 PMID 32569122

Every source the library cites

Changes

  • First published.