What is PNF stretching and will it improve my flexibility?

Whether improving your flexibility was one of your New Year’s resolutions or you were inspired by watching some tennis stars warm-up Perhaps you want to focus on regular stretching during the 2025 Australian Open.

However, a quick Google search may leave you overwhelmed with different stretching techniques. Is static stretching and dynamic stretchingwhich can be considered the main types of stretching.

However, there are also other, lesser known types of stretching, such as PNF stretching. So if you’ve come across PNF stretching and it’s piqued your interest, what do you need to know?

What is PNF stretching?

PNF stretching represents proprioceptive neuromuscular stimulation. It has been developed in the 1940s in the United States by a neurologist Herman Kabat and physiotherapists Małgorzata Knot AND Dorota Voss.

PNF stretching was initially designed to help patients with neurological diseases affecting muscle movement, e.g polio and multiple sclerosis.

By 1970sits popularity caused PNF stretching to expand beyond the clinic and into the sports arena, where it was used by athletes and fitness enthusiasts during warm-ups and to improve their flexibility.

Although the specifics of the exercise have evolved over time, PNF essentially combines static stretching (where a muscle is held in a lengthened position for a short period of time) with isometric muscle contraction (where the muscle produces force without changing length).

PNF stretching is usually performed with the help of a partner.

There are 2 main types

The two most common types of PNF stretching there are “contract-relaxation” and “contract-relaxation-agonist-contract” methods.

The contraction-relaxation method involves placing a muscle in a stretched position, followed immediately by an isometric contraction of the same muscle. When the person stops contracting, the muscle is then moved to a deeper stretch before the process repeats itself.

For example, to improve hamstring flexibility, you can lie down and ask your partner to lift your leg to the point where you begin to feel a stretch in the back of your thigh.

Once this feeling subsides, try pushing your leg back toward the ground while your partner resists the movement. Your partner should then be able to lift your leg slightly higher than before until you feel the same stretching sensation.

This technique was based on the assumption that the contracted muscle would “become electrically silent” after isometric contraction and therefore would not provide its usual level of resistance to further stretching (so-called “autogenic inhibition”). The contract relaxation method tries to take advantage of this short window to create deeper section than would be possible without the prior one muscle spasm.

The contract-relaxation-agonist-contract method is similar. However, after isometric contraction of a stretched muscle, you perform an additional contraction of the muscle group opposite to the muscle being stretched (the so-called “agonist” muscle) before the muscle is moved to static stretching once again.

Again, if you are trying to improve hamstring flexibility, immediately after trying to push your leg towards the ground, try to lift it back towards the ceiling (this is a bit without your partner’s resistance). This can be done by contracting the muscles in the front of your thigh (the quadriceps, in this case the agonist muscle).

Similarly, after this, your partner should be able to lift your leg slightly higher than before.

The contract-relaxation-agonist-contract method is said to exploit a phenomenon known as “reciprocal inhibition.” Here, contraction of the muscle group opposite to the one being stretched leads to a short period of reduced activation of the stretched muscle, allowing muscles to stretch next than normal.

What does the evidence say?

Studies have shown that PNF stretching is associated with: improved flexibility.

While both PNF methods have been suggested to improve flexibility through changes in nervous system function, research suggests they may simply improve our flexibility ability to tolerate reaching.

It is worth noting that most research on PNF stretching and flexibility has focused on healthy populations. This makes it difficult to provide evidence-based recommendations for people with the disease clinical conditions.

This may not be an effective method if you want to improve your flexibility in the long term. AND 2018 Review found that static stretching was superior in improving flexibility compared to PNF stretching. But other research found that it could provide greater immediate flexibility benefits than static stretching.

It’s similar now other types of stretchingresearch linking PNF stretching to injury prevention and improved athletic performance is relatively ambiguous.

Stretching the PNF can actually lead to small, temporary deficits in performing activities based on strength, power and speed if performed immediately before. So it’s probably best to do it after exercise or as part of a stand-alone stretching session.

How much should you do?

It looks like that single performing a contraction-relaxation or contraction-relaxation-agonist contract for each muscle twice a weekenough to improve flexibility.

The contraction itself does not have to be strong and powerful – about 20% of the maximum effort is enough should be enough. The contraction should be maintained for at least three secondswhile a static stretching element should be maintained until the stretching sensation subsides.

Thus, PNF stretching is a potentially more time-efficient way to improve flexibility compared to, for example, static stretching. In recent research we found that four minutes of static stretching of each muscle in one session is optimal for immediate improvement in flexibility.

Is PNF stretching the right choice for me?

If you have a partner who can help you, stretching your PNF may be a good option. This can also provide a quicker way to increase flexibility for those who are short on time.

However, if you are going to be doing any activity that requires strength, power, or speed, it may be wise to limit your PNF stretching until later in the day to avoid potential performance drops.