By Carl Valle
Lunges and split squat exercises are tragically undervalued and overhyped in strength training. While they are great training options, they require the same attention to detail as the other big lifts like squats and power cleans. In this article, we explore more than just typical errors seen in gyms, we deep dive into the real science of unilateral strength training.
Lunges and split squats are not true single leg exercises, but they do emphasize one side of the body over the other in unique and valuable ways—enough to consider them when programming. In this article, I also explain why many of the popular methods to train these exercises need to change or be eliminated.
Details Matter: Small Choices Add Up to Big Results
Attention to detail requires more work in the short run but pays off in the long run. Sometimes a compromise in effectiveness makes sense, like a regression to easier or simpler exercises, but discipline is everything. Once we allow an athlete to get sloppy or unfocused with an exercise, the entire well of technique is poisoned. Coaches might argue that the details I outline don’t matter. My answer is that safety and effectiveness are not optional.
This article covers five key points for lunges and splits squats:
- Make training safer as the loading grows.
- Improve the precision of both the loading and tension pattern.
- Stay current with the research on bilateral deficit parameters and asymmetry prescription.
- Know how to apply EMG studies to joint position and muscle recruitment.
- Expand on lateral motion and how it interacts with research on the sagittal plane.
I promise all of these will make a difference. They have for me. I’ve discovered that athletes become not only better lungers and squatters, but also better lifters. The value of single leg training is the athlete’s improved focus and concentration on what they’re doing—not the myths of functional strength and sport specificity.
Safer Lunges and Split Squats
Since single leg training has a history of lighter loads and more conservative programming, why the concern? While single and double leg training have differences and similarities, they both require a safe and effective training experience. The knee, hip, and back are mechanically at risk for acute and chronic injury. The best way to avoid permanent structural damage is to find which lifts best accommodate overload; we don’t need to avoid overload.
Split squats, which are bilateral squats with a staggered stance, handle overload better than lunges because they are more static and stable. It doesn’t matter if the rear leg is elevated on a bench, block, or specialized equipment. It’s still squatting. If it were a true unilateral lift, it would resemble a reverse lunge without the rear leg support. Does anyone think they could hit 150-200lb reps with pure single leg activities like they do with split squats?Split squats handle overload better than lunges because they are more static and stable. Click To Tweet
The main difference between lunges and split squats is whether the feet move: this simple statement by Shane Davenport is the heart of this article. When an athlete is lunging, they move forward or back, and sometimes forward and back. When an athlete is split squatting, most of the movement is up and down. It’s a bad idea to toss lunges and split squats into a bucket or exercise family.
From a safety perspective, coaches worry about falling with lunges and collapsing with split squats. Although I’ve seen a few spills at commercial gyms, I haven’t seen any accidents in the weight room, which may be due to light loading. Now that these exercises are considered replacements for bilateral exercises, they’ve inherited the same risks.
Heavy split squats, including Bulgarian and stationary jerk styles, require barbells, which requires managing safety from start to finish. I’ve seen plenty of missed reps in both strength and explosive barbell activities, and not one led to an injury. With barbell work, the lifts we use in training aren’t just about training the neuromuscular system. They’re also useful for bailing out. The rules of spotting, starting, and racking the weight must apply with unilateral lifts.
Video 1. Elevating the foot on a small box can keep athletes ready to bail if something were to go wrong. Regardless, always use a good squat rack. Note the active foot and toe in the video. Not all athletes can do this if they have a history of turf toe or similar injuries.
For the most part, lunges are dumbbell-driven, and split squats are now barbell centric. With lunges, it’s rare to see someone fail because of the loads typically used, and the rate of fatigue is far slower because of the prescribed loads and rep ranges.
Lunges tend to be slightly more complex and demanding, as they include more movement and sometimes alternate legs. I consider them supportive exercises and rarely load them so that an athlete would miss reps or not be able to complete the work prescribed.I consider lunges supportive exercises and rarely load them. Click To Tweet
Safety matters more when you push an athlete. If the athlete does not risk failure, the load is supportive and won’t push adaptations as far, which compromises the goals of increasing strength and power. Mitigating risk by better understanding these two species of leg exercises will enhance training by improving both safety and results.
Prescribing Loads and Tempos
No real rules exist for loading lunges and split squats, but there are practical guidelines about how much to load, the way to progress, and when to speed up and slow down. Most coaches would agree that we can overthink any exercise and program it to death. I’ve learned some practical principles from other coaches that made a difference.
Here is a list of smart concepts that may work for you and your athletes that are worth trying or at least considering. You don’t need to follow them exactly.
Lunges—Front, Side, Walking, and Reverse
- Reverse and side lunges are great complementary exercises after performing primary lifts.
- Walking and front lunges are fine if you include hip-dominant movements in training.
- Load lunges by either adding weight or adding sets, not adding complexity.
- Keep the movements faster and don’t use slow eccentric tempos as they elicit poor responses.
- Dumbbells, kettlebells, and heavy weight vests are good for moderate loading.
Split Squats Including Lateral Variations
- Load sagittal plane split squats in the traditional strength ranges.
- Lateral options should be near bodyweight for higher rep ranges but still remain in the single digits.
- Speed should be slower than lunges but Time Under Tension isn’t necessary.
- Isometric variations are great as long as athletes perform them with maximal effort.
- Flywheel and other eccentric enhancers overload the legs and hips well.
Strength training is generally more supportive than explosive training and speed training. And although you want to have a great strength system, it’s better to put time and resources into a great speed program. The range of motion for exercises on the ground tend to be the same as, or less than, bilateral exercises because the rear leg prevents going deeper unless the front foot is boosted up. Additional boxes do add some potential risks, but if they”re wide and low, they are good complements to traditional step-up exercises.
Video 2. Weighted vests, kettlebells, and a long enough stride make walking lunges a great general preparation exercise for athletes. While I prefer reverse lunges when athletes aren’t able to do walking lunges effectively, I see them as a sign of poor movement literacy.
The most practical point in this article is that loading lunges and split squats should not be random, and progression should not be blind. It’s easy to think of sets and reps first, but these considerations should be last on the list.
When programming, think about patterns with lunges and overloads with split squats. Lunges are about fluid motion, which is why slow tempos and isometrics don’t jive. Split squats can handle a load better because the rear leg is planted, but they are not safer. It’s just likely that the coaches are vigilant.
Bilateral Deficit and Unilateral Symmetry
Two primary questions coaches have with single leg exercises are how much one can load and what is required when one spots an imbalance. The answers seem simple and straightforward, but putting them into practice isn’t easy. The bilateral deficit, even today, is an unfinished subject with regards to the science. Also, imbalances are difficult to manage because precise thresholds and unique circumstances make true functional impairments difficult to ascertain. Relying on trial and error for loading isn’t good enough—we have great resources to get started when addressing the two concerns.
Loading Single Leg Exercises
Let’s address the first challenge, how to load the legs with various single leg exercises compared with their bilateral counterparts. Simply comparing exercises based on support-leg contribution is oversimplified because we must think about the rest of the body. Single leg training doesn’t use half the resources of a dual leg variation, so it’s time to move away from direct comparisons.
Split squats, elevated or not, are not single leg exercises. Don’t throw away the formula from Roger Enoka, but be mindful of the intent of his research. Also, the strain on the body is more complex than represented by the total numbers on the bar. The stress patterns are unique, and we can’t compare them with bilateral variations. It’s not that squatting with two legs is safer because everything is balanced better; it’s that unilateral loading is not safer because the simple math conveniently indicates less total load.With single leg exercises, strain on the body is more complex than the weight on the bar shows. Click To Tweet
For example, the split squat uses the rear leg differently, thus changing the body’s recruitment pattern. It’s possible the psoas major is recruited more and less, but I’m more concerned with torque on the pelvis. So far I don’t think it’s an issue with medium weight, but like any lift, progressive overload will become an issue as the athlete advances.
If the spine is a limiting factor with heavy back squatting, eventually the theoretical advances of the bilateral deficit will make the loads very heavy for split squats. With all of the core training articles and educational products, one would think we’d see a solution to vertical force transmission and spinal stability. So far we see a lot of athletes getting better at exercises due to progressive training but not better at sports.
Video 3. Some programs use the split squat with the rear foot elevated as a primary lift, while others use it as a major contributor to leg development. You can load the lift more than a reverse lunge, but remember it’s not a true single leg movement.
Now for asymmetry. Simple strength training patterns are great ways to bring up a weakness. Because they are not as demanding skill-wise, we know if the problem is being taken care of globally. Specific asymmetry could mean the athlete is less skilled. For simple actions like squatting and lunging, symmetry issues should resolve.
Jumping and sprinting will likely reveal a natural and normal asymmetry, but interpreting this requires additional assessments—specifically history of injuries and girth measurements of legs. Here’s my number one gripe: when a leg is both weaker and smaller, the staff doesn’t believe it’s something to worry about. Even when the athlete was injured previously in the same area.
I suggest this winning strategy. Add extra work before a primary lift along with additional sets after the secondary exercises. I’ve seen plenty of athletes improve from a steady diet of tutoring the leg that needs to be brought up. It’s up to the staff to define when it’s sufficiently balanced.
Nobody needs to be perfect, but allowing asymmetry to run wild because the human body’s nervous system is plastic doesn’t work in the long run when fatigue and speed interact at the wrong time. As long as you’re paying attention to the big picture, you don’t need to worry about asymmetries, but you should consider them as a possible cause of problems.
Muscle Recruitment and Joint Position
An athlete’s pelvic motion, amount of lean, and shin angle determine how the muscles contribute to these exercises. It’s easy to get lost in the small details of research, such as a lunge’s length of stride or how vertical the tibia is in a split squat. To make things easier without dumbing down the exercises, we should overload the stressed leg in a way that distributes the stress safely to the quads, adductors, abductors, and hamstrings.
The distribution of unilateral exercises, even when done properly, is never ideal since they’re still weight training movements, not sporting activities. While a lunge may be specific to squash or other sports, it’s not dynamic enough even when performed fast with a light load. The goal of this section is to make the movements a little bit better by coaching up the technique so the exercise meets the goal.
Video 4. Double boxing or using deficit split squats can play with torso position for plyometric progressions. Stay in a lean for squatting patterns. Many split squat variations cut the stroke distance slightly as the rear knee blocks the range of motion for some athletes.
Split squats are partial range movements even when the rear leg is elevated. Slide board options can create problems if the athlete runs out of range of motion early. For the most part, I’ve yet to see a rock bottom split squat, even with the front leg elevated.
Back squatting is highly connected to the anatomy of the hip joint. Lunging and split squatting are easy on the labrum provided the load is sane. A shallower squatting pattern won’t mean the end of the world, but it’s something to think about. Single leg squats are considered safe since bodyweight loads them, although pistols tend to round the lumbar spine more than heavy back squats.
How this all relates to muscle activity may seem confusing. Base priorities on joints when creating a roadmap for what the technique should be.
Video 5. This is an example of a full single leg squat that turns into a pistol because of depth. It shows how single leg training needs to follow the same rules as bilateral exercises. Rounding the lumbar spine is controversial. I worry about hip health and use depths that maintain pelvic position.
Several studies on lunges, from how the dumbbell is carried to the direction performed, illustrate why the details matter for muscle recruitment. Reverse lunges are the better option because they’re easy to do correctly, but walking lunges are also useful for performance. It’s commonly believed that reverse lunges are easier on the knee, but research does not support this beyond a few promising studies. Based on my experience, athletes tend to be fine with reverse lunges, but that’s not real evidence.
Remember, the absence of pain is not a sign of health. Chronic loading with contraindicated positions regardless of the exercise is bad news over time. Athletes can perform with frayed tendons, bulging discs, and degenerative knees, but only for so long. When the body breaks down, it can’t perform, regardless of whether the athlete feels pain.
Video 6. Reverse lunges make up the bulk of my program, with lateral squats coming in close second. While the research is scant on knee health, reverse lunges do seem to feel more comfortable for those who are managing overload from games and poor surface access.
Guidelines such as whole foot pressure, movement between the femur and the shin, and retaining the motions of their bilateral counterparts are more than enough to get started. Small details like choosing between step heights for the supported leg, elevated positions of the rear leg, and where to put the barbell or dumbbell are based on an athlete’s experience and range of motion.
If you follow the same safety and recruitment strategies of bilateral lifts and use the rear leg as a way to balance the front and not as a means for propulsion, you should be fine.
Lateral Motion: Lateral Squats and Side Lunges
The lateral movement exercises are less researched than sagittal plane motions, and this needs to change. Some newer research has investigated the commonly used exercises and compared them, but even these studies resorted to crude hamstring and quadricep measurements instead of looking at adductors and other muscle groups that contribute to athlete success.
When we think about split squats, we tend to think about Bulgarians. We should also think about wide stance activities, within reason. A lateral motion doesn’t occur in one dimension. It occurs in three. And while we can’t see the rotation, we know the muscles that help drive propulsion in the transverse plane are strengthened.
Lateral squats and side lunges are especially helpful for those who simply need a strong base of support outside conventional hip width or shoulder width squatting, be they bilateral or unilateral.
Video 7. Athletes can build up to 1.2 times their body weight doing lateral squats without problems if they are skilled and prepared. Teaching the lateral squat is easy and can be part of warm-up or post-training work.
Cutting’s side step motion is similar to a lateral squat and side lunge, and if it’s important for injury reduction and performance, should we not load it aggressively? I don’t advocate a one rep maximum test for the movement, but what we assess is what we usually value. Also, I am aware of the limitation of specificity, but it seems odd that we fear deceleration laterally while we program lateral lifts with near throwaway effort.We need to improve lateral lifting beyond adding a few exercises at the end of a workout. Click To Tweet
Overall, we need to improve lateral lifting beyond adding a few exercises at the end of a workout. I was guilty of this and assumed the sport would take care of itself. If that were the case, however, I would not lift at all.
Second, lateral lifting is easy on the ankle compared to excessive plyometrics because the joints are stacked. I’ve learned to implement the “decrease the wear and tear but still prepare” element of conventional strength training. Now I use just enough lateral bounding and agility work to ensure athletes are ready without creating unnecessary stress. Thanks to Boo and other coaches, I know my athletes’ change of direction abilities are better, and their joints can take a break during the off-season.
Video 8. Side lunges do not replicate change of direction requirements, but they’re a good option for those wanting to transition to specific work without as much shock to the system. A few sets during the GPP or early training phases will minimize soreness and fatigue.
Finally, why the specific use of the terms side lunging and lateral squatting? I treat each movement much differently because I want speed with the side lunge patterns and I want tension on the squatting. Deceleration will take care of itself in a holistic program. I see side lunges as great GPP options and lateral squats as SPP supportive exercises. I used to switch and have frontal plane lunges in-season, but I find them harder to manage compared to lateral squats, which are slower and more consistent.
Beyond Lunges and Split Squats
If you want to make a difference, you have to know the difference between great coaching and master coaching. I’m halfway there on my journey and love learning from better professionals who are experts in their craft. It’s good to think about how to do something better—just avoid using the thought process to justify stubbornness and resistance to change. Evaluation is about improvement. Don’t only follow trends.