Diaphragm training using conventional resistance techniques

One of the ways to improve performance is through respiratory muscle training.  In a previous post, this was reviewed as well as using the Hexoskin shirt to better focus on the diaphragm as the target.  However, one of the drawbacks to conventional RMT is that one needs to take maximal inspirations through a mouthpiece against a challenging resistance.  Most people won't have difficulties doing this, but unfortunately some of us have cervical spine disease that can be stirred up through the heavy use of the accessory muscles in the neck.  Personally, I had great results with the Powerbreathe but was running into increasing difficulties with neck pain flare ups.  The following post will lay out an alternate way to train the diaphragm without involving the neck or accessory muscles of respiration.  Whether this produces as good a net result is of course unproven, but I will attempt see if it does over the next few months.

Firstly, diaphragm training using various breathing techniques is certainly not new or novel.  Many Yoga and Pilates breathing techniques employ isolated diaphragm enhanced motion as part of the training.  The basic idea is to breath in without moving the chest but instead, moving the upper anterior abdomen outward.  I previously showed how the Hexoskin can be very handy in providing biofeedback, but simple observation can suffice.  Most diaphragm training studies employ just passive breathing, occasionally with pursed lips or mild hand pressure over the abdomen.  However, it stands to reason that a challenging resistance to the outward abdominal motion should provide a stimulus for diaphragm strength and endurance.  Is there any evidence for this in the literature?

Before looking at this directly, let's review an interesting study of world class power lifters and diaphragm thickness, ventilatory function.  The conjecture was that since power lifters are doing very intense squats, bench press and deadlifts (which are all associated with build up of intra abdominal pressure), the supporting muscles consisting of the diaphragm (and others) will also be strengthened.  The comparison between matched Powerlifters and Control subjects show thicker, stronger diaphragm muscles in the lifters:

The maximal inspiratory and expiratory pressures were high in the lifters but not some other parameters.

 

 Diaphragm thickness did correlate with inspiratory/expiratory pressures.

Finally, the total weight lifted tracked very closely to the diaphragm thickness.

The conclusion of the study:

In conclusion, this study demonstrates that world-class
powerlifters have greater inspiratory and expiratory muscle
strength and diaphragm thickness, yet similar pulmonary
function compared to a group of matched untrained controls.
Improvements in ventilatory muscle strength and
thickness following acute and chronic resistance training
facilitates the high-intensity manoeuvres and protects
against spinal injury within powerlifting and may serve to
improve resistance from ventilatory muscle weakness
encountered with ageing and in some chronic disease states.

Another study utilized a series of abdominal exercises to improve ventilatory parameters in teens.  The exercise protocol used the following individual modalities:

With the following sets/reps:

During each exercise
session, all muscle groups were trained actively,
with no external aid, reaching between 200 and 300
repetitions per session. Sessions took place twice
weekly, each lasting 45 minutes

The results showed good improvement in inspiratory and expiratory pressures, although the diaphragm was not isolated.

Finally, probably the most specific investigation was done having the subjects actually breath with weighted balls on the abdominal area while being extensively instrumented:

Yes, the study was published in Spanish, but we'll get some translations thanks to Google.

After obtaining a basal record with a standard
Normal (PN), the subjects were invited to change the pattern
piratory in order to achieve a predominance of movement
abdominal. This pattern was called "abdominal pattern" (PA).
Then, the PN was allowed to recover and it was supported on the
abdomen in the umbilical region loads of 1, 2, 4 and 6 kg of
weight.

The weight range was therefore up to 6 kg.  The PA pattern was the abdominal, the PN was the normal pattern of breathing.

The effectiveness of the adoption of the respiratory pattern with
the predominance of the abdominal component (PA without load
and with load) was evaluated by the thoracic movement
and abdominal (inductance plethysmography). All the
subjects were able to modify their breathing pattern
normal thorium to achieve greater abdominal mobility
as requested (Fig. 2)

The solid circles show good diaphragm motion especially with the higher weights:

Fig. 4.- Gastric pressure (Pga), esophageal pressure (Pes) and
transdiaphragmatic (Pdi) during the different stages.
The asterisks indicate a significant difference (p 0.001)
with respect to basal PN.

Fig. 5.- Mean transdiaphragmatic pressure / pressure ratio
maximum transdiaphragmatic (Pdi / Pdimax) and tension index
diaphragm time (TTdi) during the different stages.
The asterisks indicate a significant difference (p 0.001)
regarding the basal PN and the PN with loads. The line
dotted corresponds to the value of the TTdi index above
from which the diaphragm will develop muscular fatigue.

 

Then, the PN was allowed to recover and it was supported on theudy. In this way the stages were establishedwith 4 kg (PN 4), PN with 6 kg (PN 6),)
en, the PN was allowed to recover and it was supported on the. In this way the stages were established2), PN with 4 kg (PN 4), PN with 6 kg (PN 6),th 6 kg (PA

Although the authors were not very impressed with the results, they only used a relatively low weight at the maximum tested (6 kg).
Here is their conclusion:

Our findings suggest that the charges applied
on the abdomen produce changes in the mechanics of
that affect the function of the diaphragm. The charges
increase proprioception related to the movements
respiratory cough and descent of the diaphragm but, due to
the small magnitude of the changes seem to be insufficient
to produce respiratory muscle training

And 

The most relevant results of the present study are:
1) Adoption of the PA was facilitated by the placement
of loads on the abdomen, 2) only with high load (6
kg with PN and with PA) the preload of the diaphragm increased slightly but significantly, 3) with the PA (with and without load) the Pdi / Pdimax and TTdi indices, if well they increased significantly, they kept
below the fatiguing and training values for the diaphragm.

Hence, they found that loads improved the subjects voluntary diaphragmatic motion control but did not reach a "fatigue" level to the muscle.  One wonders why they did not go higher than the 6 kg loads to see what would happen.


About 3 weeks ago I began a program of abdominal breathing against resistance.  The idea was to try to isolate diaphramatic motion, with a series of weight plates on the upper abdomen, that should move up during inspiration.

To start with, 20 lbs (10lb x 2 plates) was used for 5 minutes.  The focus was on not moving the chest and just moving the weight plate up and down.  I definitely see the advantage in abdominal breathing control doing it this way.  The plate can give both tactile and visual feedback that you are doing this correctly.  To verify that the abdomen and not the chest is being moved, I wore the Hexoskin shirt and recorded the tracing below:

The darker blue is the abdominal motion, light blue is thoracic.  Compare the above to the pattern seen with an intense interval:

Here we see that both abdominal and thoracic motions are matched and equal.

My plan is to gradually raise the weight, but keep the time at 5 minutes (to make it more manageable).  I am currently up to 25 to 30 lbs (depending on my level of fatigue for the day).  Although there is no conventional "muscle failure" as in a biceps curl for example, by the end of 5 minutes there is definitely a sensation of fatigue while breathing.
Whether this will produce a performance improvement similar to a inspiratory resistive device like a Powerbreathe is of course unknown.

Summary:

• It is possible to isolate diaphragm muscle activity by breathing in a particular pattern.  This consists of minimal thoracic and focused abdominal breathing motion.
• Powerlifters by virtue of training with very high intra abdominal pressures, have stronger, thicker diaphragms. 
• It may be possible to improve maximal inspiratory pressure and peak expiratory flow rates by a series of abdominal exercises. 
• There is also a possibility that doing diaphragm related breathing while under resistance, may improve the same parameters.  Theoretically, overload resistive training should enhance both endurance as well as strength.
• The Hexoskin shirt can give valuable feedback as to the proper diaphragm isolation breathing method.
• Having an even small weight load on the upper abdomen can improve the selective breathing motion involving the diaphragm.
• Whether the above styles of abdominal diaphragm training translate to endurance sport performance improvement is still unclear.