Scientific Aspects of Stance Training

Here is a rundown of the physiological adaptations that are likely to occur during stance training used in various martial arts styles.  In summary, they are (1) blood pressure reductions and oxygen efficiency due to restricted blood flow, (2) increased stability due to comparatively lower stretch reflex responses and increased muscle endurance, and (3) increased power generation due to joint angle specific increases in muscle strength and changes in muscle fiber recruitment.  These points are elaborated on below.

1. Blood Pressure Reductions 

Holding a stance involves isometric muscle contractions where the muscle fibers stay the same length throughout the exercise.  This type of contraction applies consistent pressure to the arteries, limiting blood flow to the areas where the contractions occur.  This causes a build-up of metabolites which normally dilate the blood vessels and increase blood flow.  Immediately following the exercise, the muscles stop contracting and the blood, along with the metabolites, can flow to the rest of the body. The causes blood pressure levels to be reduced during the post exercise period, sometimes with the effect lasting for a day.  If this practice is done regularly, say a few times a week for 2-minute bouts at a time, blood pressure can be reduced for several weeks after the training is halted.  This is likely due to the blood vessels becoming more responsive to changes in heart rate and exercise demands, allowing blood pressure levels to remain at healthy levels during regular daily activities.

It should be noted that practitioners of stance training often claim increased “qi flow” during the exercise and that this is responsible for its health benefits.  The concept of qi is difficult to define and a different interpretation could be the source of the misunderstanding; however, the idea that there is increased flow during an isometric exercise like stance training is not supported in terms of the blood.  Arterial blood flow is restricted by the contracting muscles while holding the stance causing the metabolite build up already mentioned, but this process also restricts oxygen and nutrients from getting to the active muscles.   Over time, the muscles are forced to adapt to the restriction by functioning more efficiently and increasing stored oxygen within the muscles.  A similar process occurs during blood flow restriction BFR training, where weightlifting exercises are done with a belt tied around the active limb, directly limiting blood flow to the working muscles.  It has been demonstrated that the adaptations to BFR are comparable to those without the restriction but using heavier weights.  In other words, more gain with less work.

2. Stability

Generally, stances provide stability due to do the lowering of center of mass and then wider base of support of the feet.  It will require more force to move an object under those conditions as the person in a stance will have a mechanical advantage compared to someone who is not.  However, the way stances are trained can also improve stability or it might make it worse.  The stretch reflex can have a direct impact on your ability to maintain stance when being attacked.  If you have ever been bounced out of your stance of your stance by someone pushing on you, you might wonder why you seem to have momentarily lost control of your body.  The same mechanism that the doctor uses to check your reflexes with a small hammer is at play in stances as well.  In the lab or doctor’s office, it’s been noted that holding a small muscle contraction while the stretch reflex is being tested, can increase the reflex response.  This means that if we hold a stance tightly, it will be easier for people pushing on us to activate this reflex for us, and momentarily take control of our bodies.   One experiment demonstrated that the stretch reflex was greater when subjects attempted to hold fixed joint angles than when they merely needed to support an equivalent amount of weight in a specific direction. For a stance then, what is important is that you support your body weight, and not be overly focused on leg position. Staying as relaxed as possible while supporting the body weight at the desired stance height is therefore preferable to emphasizing leg position within the stance. 

Regardless of how they are held, practicing stances as an endurance exercise can induce physiological changes that can improve one’s ability to be more relaxed and help to avoid unwanted stretch reflex activation.   Additionally, stance training, like other forms of endurance exercise, will cause changes in the muscle fiber type.  When you first begin holding stances, and you are not able to do so for very long, you may notice that your legs muscles are particularly tense.   This tension is due to lots of muscle fibers being recruited to support the body’s weight.  As you improve, your muscles will adapt by increasing their endurance capacity; fast twitch muscle fibers used for short bursts of energy will begin to change into slow twitch fibers that will not fatigue so quickly.  This adaptation means that over time, less fibers will be needed to do the work of holding the stance, freeing up other fibers to relax and be ready for any changes in movement.  Not only does this increase one’s ability to move and make adjustments to the stance, but the greater relaxation will also mitigate the effects of the stretch reflex if you are pushed or perturbed abruptly.

3. Power 

Having a strong base of support and connection to the ground can help deliver stronger attacks with the upper body.  Additionally, holding a posture will develop the leg muscles in a focused way that will contribute to explosive strikes.   Unlike lifting weights which strengthens the entire range of motion the joint moves through, isometric exercise tends to predominantly strengthen the muscles at and around the specific angle the joint is held.  Thus, holding a stance at a height you will likely be fighting in and generating power from will strengthen the muscles in that range of motion.

Some martial artists practice very low stances because they are more intense and believe this will make them stronger overall.  If your martial art requires lower stances and to be stronger at increased ranges of motion, that would provide some justification for the practice.  However, if one is mainly interested in generating power from a specific range of motion, then this practice is not optimal

As mentioned above, muscles will increase their endurance over time, requiring fewer fibers to be contracted to hold the stance.  The relaxed muscles not needed to support the body’s weight are now free to wind up or lengthen in preparation for explosive movements. Therefore, stance training increases the endurance required for fighting and well as indirectly aids in the ability to perform techniques requiring speed and power.