Proprioceptive Neuromuscular Facilitation (PNF) uses a cycle of isometric and relaxed stretches to switch off the stretch reflex and teach the muscles a new “safe” length.
You move into your maximum stretch, then tense against the stretch for several seconds. Once you relax the tension, you are able to slide further into the stretch because your voluntary muscle contraction has switched off the stretch reflex. You can either hold this position, or repeat the tense-relax cycle again to sink further into the stretch.
If you choose to repeat the tense-relax cycle, only do so until you get no further improvements. When you have reached your lowest point, try to hold the position for 30 seconds. You can optionally hold a tension here also, but it is hard work. This final tension supposedly helps to reinforce the new “safe” length as far as the stretch reflex is concerned. This whole process is considered a single rep.
Move out of the stretch and rest for about 45-60 seconds, then do the whole thing again. Repeat for 3-5 reps.
The length of the tension required will vary from person to person, from 5 seconds to minutes, as will the number of tense-relax cycles and reps you can do before you stop seeing improvements on any given day. Don’t fight it, go with the flow.
This is the most efficient form of stretching I’ve found, but it can be hard work and it’s easy to get over-excited and injure yourself, so be careful.
Frequently Asked Questions (FAQs)
Q. Do I have to do PNF to get into the splits?
A. No. There are many ways to stretch and PNF is just one of them. Admittedly, it is probably the most efficient way to increase flexibility, but it is not the holy grail. Stretch regularly and your flexibility will improve.
Q. How often can I do PNF stretching?
A. The answer to this depends on the intensity level of your PNF stretches. If you go to a physiotherapist for treatment they might do PNF with you every day, but the style of PNF they use involves short low intensity contractions.
Most popular stretching methods advocate longer and stronger contractions, which are more like weight training. As a result, it is usually advised that you have at least 1 day of rest between PNF sessions.
So you must make a judgment about how much effort you are putting in, and how soon you feel you can attempt another PNF session. I would suggest you start with 2 sessions per week, then increase the number over a few weeks until you find the optimum level for you. Also, just because you are not doing PNF one day, it doesn’t mean you should avoid stretching. You can still do light static stretches.
Q. Is PNF safe?
A. This is a bit like asking if cars are safe. If you drive carefully, cars are safe. If you drive recklessly, cars are dangerous. The same applies to PNF. It is a fast and safe way to gain flexibility provided you use it correctly. It is also the quickest way to get injured if you work too hard and use it too often. The devil is in the detail.
For more information see:
- Isometric Stretching
- Stretching and Flexibility by Brad Appleton
- Stretching Scientifically by Tom Kurz