Far too often as coaches we read articles that are full of scientific research, but a lot of times bridging that gap to practical application is far more difficult. One of the biggest challenges to coaches is fitting in various types of training with their athletes or clients in just a few sessions a week. How do we combine all the necessary components of proper training, maximal strength, speed, agility, deceleration, acceleration, change of direction, isometric strength, endurance, and sport-specific training?

The truth is that many techniques we use cover more than one aspect at a time. If not, a coach needs to reevaluate their training philosophy. A component of training that has been receiving a lot of attention is the concept of stability training. Joint stability seems to be a cornerstone of any training program. However, what makes up stability training may not be so clear.

The Stability Component

Stability can be as vague of a term as “strength” is. Without overly complicating terms, a definition I like is this: “Joint stability refers to the resistance offered by various musculoskeletal tissues that surround a skeletal joint. Several subsystems ensure the stability of a joint. These are the passive, active and neural subsystems. The opposite of stability is instability.” (1)


For a large majority of coaches, such a definition isn’t overly helpful. A more practical definition may be, "the effective accommodation of the joints to each specific load demand through an adequately tailored joint compression, as a function of gravity, coordinated muscle and ligament forces, to produce effective joint reaction forces under changing conditions.

Optimal stability is achieved when the balance between performance (the level of stability) and effort is optimized to economize the use of energy. Non-optimal joint stability implicates altered laxity/stiffness values leading to increased joint translations resulting in a new joint position and/or exaggerated/reduced joint compression, with a disturbed performance/effort ratio.” (2)

Truthfully, this doesn’t seem to help that much either. For most coaches, stability training and slow isometric movements are typically done on the floor. It is almost seen as a “necessary evil” that takes some time from our normal training; drills that we feel obligated to do and try to get over with as fast as possible. While such drills may be necessary, the progression to more dynamic and real world base drills is far more important in performance related endeavors.

Sport-Specific Stability

The truth hurts, but real sport-specific training is beyond most coaches. REAL sport-specific training requires a highly developed knowledge of biomechanics of sporting actions that occur during the sport. The nice part is most athletes are not prepared to perform true sport-specific training because they are not “fit” enough to benefit from the training. However, we do need to understand that our training does need to progress to speeds and challenges that are faced in real world and sport.

One of the easiest ways to achieve stability in more practical ways is to emphasize the role of single leg training. Of course, most coaches already use single leg training in one form or another, but rarely give it the attention it truly deserves. No, you don’t have to stop your bilateral lifts, but looking at the role they play in your training is important.

Some coaches are still believers in the idea that squats, deadlifts, and Olympic lift variations will take care of most lower body and stability type of training. Yet, even non-field sports such as Olympic lifting have even used single leg training as a means to improve these very qualities for their competitive lifts. Research also tends to support that utilizing one-legged drills is important for several reasons...

Maximal Muscle Contractions: A 1978 study demonstrated that unilateral leg extension exercise created higher levels of maximal voluntary muscle contraction than bilateral leg extension training. (3) Yes, I know, LEG EXTENSIONS! This can’t really be indicative of true functional and sports training. Yet, another training study does support this in a more functional environment.

Higher Ground Reaction Forces: “Ten well-trained male volleyball players performed one-legged and two-legged vertical countermovement jumps. Ground reaction forces, cinematographic data, and electromyographic data were recorded. Jumping height in one-legged jumps was 58.5% of that reached in two-legged jumps. Mean net torques in hip and ankle joints were higher in one-legged jumps. Net power output in the ankle joint was extremely high in one-legged jumps. This high power output was explained by a higher level of activation in both heads of m. gastrocnemius in the one-legged jump. A higher level of activation was also found in m. vastus medialis. These differences between unilateral and bilateral performance of the complex movement jumping were shown to be in agreement with differences reported in literature based on isometric and isokinetic experiments.” (4)

Most sporting actions are determined by ground reaction forces. Typically, greater speed and power is developed by creating higher ground reaction forces. The majority of sports have a transition phase of our base of support being applied only by one leg, whether this is in straight ahead running or change of direction. This may mean that more advanced forms of training is spending more time learning how to develop power and strength on one leg.

However, how does this all transition back to the idea of providing body stability? Reducing our body support has a profound impact on how our body recruits different muscles.

Studies have shown in just bridging exercises the body recruits more muscles in a less stable position than more stable. “In general, the ratio of the internal/external abdominal oblique activity was about 1. However, during the unilateral bridging exercise, the ipsilateral internal/external abdominal oblique activity ratio was 2.79 as a consequence of the significant higher relative activity of the internal oblique compared to the external oblique.” (5)

Single leg drills tend to work more the adductors, gluteus medius, and gluteus minimus than their bilateral counterparts. This is tremendously important, as much of our pelvic stability is reliant upon the strength of these muscles. If our pelvis is more stable, our ability to exhibit force goes up. In fact, weakness in these muscles can show themselves in problems such as Trendelenburg gait where the SI joint and lumbar spine can be at great risk of injury.

Where to Start?

It may not be that hard to convince people that they should utilize single leg exercises. However, many do not have a definitive system in which they implement these movements. Just as with any training, we need to lay down progressions for proper usage. If we are not aware of the impact of jumping into advanced versions of single leg training, we can easily set-up our athlete or client for injury as forces applied to the body in single leg training aren’t just double that of bilateral, but can be exponentially higher.

1. Stable before unstable: A good rule of thumb for just about any form of training, this is especially true in single leg training. Most coaches rush into single leg plyos or stepping versions of lunges without observing if their client can demonstrate control and proficiency in safer environments. A base level exercise for dynamic lunging would be a static position. Watching for proper stride length, knee valgus, and lower leg control is key in being able to provide appropriate more advanced forms of single leg training. In drills such as step-ups, working from a low step in a slow controlled manner is the correct starting point where many coaches work from higher steps that often cause compensation.

Beginner Series:
• Stationary Single Leg Squat
• Stationary Single Leg Squat Lateral
• Stepping Lunge Forwards

Intermediate Series:
• Stepping Lunge Reverse
• Stepping Lunge Lateral
• Elevated Rear Leg Single Leg Squat

Advanced Series:
• Rear Crossover Lunge
• Mixed Patterns
• Suspended

2. Work on Different Loading Patterns: The placement of load is commonly a neglected aspect of programming. Beginning with the load down by the hips either holding a dumbbell or kettlebell places the load through the body without much of a change in center of gravity. We can go through a progression of placing weight on the upper back, front of the body, and overhead. These variations all change the center of gravity and perceived load. More advanced loading patterns can be sandbag shoulder, one-arm weight overhead, mixed loading patterns (one arm up, one arm down), etc.

Beginner Series:
• Down By Side
• Goblet

Intermediate Series
• Front Rack
• Overhead

Advanced Series:
• X Series 1: One down by side, other in front rack
• X Series 2: One in front rack, other overhead

3. Range of Motion (ROM): A simple principle of loading and progression is to alter the range of motion. Whether it is due to mobility and flexibility issues, or confidence and strength, ROM is a vital component of any drill. The eventual goal of any lift should be to obtain optimal ROM. This can vary depending upon one’s structure, but identifying what is optimal for that individual should be identified in early stages of training. Increasing ROM can be a means of raising intensity of any drill and decreasing the ROM is can serve as an important means for progressing individuals that show significant signs of instability.

Progressional Series:
• Front Foot Elevated
• Flat on Ground
• Rear Foot Elevated
• Suspended

4. Complexity: An often-overlooked variable is exercise complexity. This can be much hard to quantify, but can be powerful in accomplishing goals of improving stability and performance. Increasing complexity by changing stepping patterns, mixing loading patterns (cross patterns for example), and increasing speed can fit into this category, as the body now relies on different neural loops to guide the performance.

Examples of Complexity:
• Rotational Lunge
• Split Snatch
• Lateral Step Swings
• Suspended Squat Thrusts
• Staggered Cleans

Having a series of specific progressional series for lunging, single leg squatting, single leg deadlifts, step-ups, and single leg explosive lifts is critical. While most coaches are quick to implement single leg bounding and plyometric drills, these preparatory series can do a lot for performance, by allowing coaches to properly utilize more advanced training techniques when necessary.



1.Panjabi MM. (1992). "The stabilizing system of the spine. Part II. Neutral zone and instability hypothesis."]. J Spinal Disord 5 (4): 390–7.

2. Vleeming A, Albert H B, van der Helm F C T, Lee D, Ostgaard H C, Stuge B,
Sturesson B.

3. 'Contralateral Influence on Recruitment of Curarized Muscle Fibers during Maximal Voluntary Extension of the Legs,' Acta Physiologica Scandinavica, vol. 103, pp. 456-462, 1978).

4. A Comparison of One-Legged and Two-Legged Countermovement Jumps,' Medicine and Science in Sports and Exercise, vol. 17(6), pp. 635-639, 1985

5. BMC Musculoskelet Disord. 2006 Sep 20;7:75.Trunk muscle activity in healthy subjects during bridging stabilization exercises.Stevens VK, Bouche KG, Mahieu NN, Coorevits PL, Vanderstraeten GG, Danneels LA.Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, Ghent University, Belgium. Veerle.Stevens@UGent.be