Q: How do the Inspiratory muscles contribute to the breathing process?

Weakness of the inspiratory muscles can result from a number of causes, including disease, but a potent influence upon their condition is the amount of exercise they receive. The phrase 'use it or lose it' applies equally well to the inspiratory muscles as it does to your leg muscles. If you get out of breath on the stairs, then you'll take the lift, with the consequence that your inspiratory muscles get less exercise.

As they become weaker, the level of physical activity that brings on the breathlessness gets lower, so you avoid the stairs even more.it's a vicious cycle of breathlessness, lack of exercise and inspiratory muscle weakness. In addition, the use of oral steroid medication (not inhaled steroids) to control lung inflammation in conditions such as asthma and emphysema has been shown to cause weakness of the inspiratory muscles. This weakness can impair lung function and can be counteracted by inspiratory muscle training. N.B. inhaled steroids do not cause inspiratory muscle weakness.

Breathlessness is a common feature of lung and heart disease, but as we know all too well, its also a feature of normal exercise. Recent research has shown that the strength of the inspiratory muscles has a direct influence on how hard we can breathe and how breathless we feel whilst doing it.
If the muscles are weakened or fatigued (inspiratory muscles can fatigue by as much as 20%) then we can't breathe as hard and breathing requires greater effort; we experience the effort as breathlessness.
A useful analogy is to think about how much heavier a barbell feels on the 12th repetition than it did on the first. In the same way, if the inspiratory muscles are weakened or fatigued, breathing feels harder.

The tried and tested POWERbreathe training regimen is 30 breaths twice per day. Each session takes around 3 minutes and can be completed virtually anywhere.

PB = 30 x 2

A comprehensive instruction manual accompanies every POWERbreathe and includes information on training for performance and warm-up. Results are measurable in a little as 3 weeks, with almost full training benefits accrued within 6 weeks.

Q: How does exercise affect my breathing?

When we climb hills or stairs, we are suddenly exposed to high intensity exercise that, for most of us, is above our lactate threshold. At these intensities our breathing moves out of it 'comfort zone' and increases steeply. This sudden increase in inspiratory muscle work is perceived as breathlessness.
At low and moderate intensities, breathing is very modest, but as the intensity becomes more strenuous breathing increases steeply becoming almost exponential. During the majority of your everyday activities, your breathing operates well within its 'comfort zone'. Only when you venture above the lactate threshold (hill and stair climbing territory) is breathing stimulated sufficiently for the breathing muscles to be challenged. Exercise above the lactate threshold is usually short and sharp.
In other words, your breathing is not exposed to a suitable training stimulus for a sufficient duration or with sufficient frequency for the breathing muscles to experience a full training adaptation. Even if you could sustain the high intensity exercise, its doubtful whether this type of unloaded breathing would provide an adequate training overload to elicit maximal training benefits; its akin to a bicep curl without the dumbbell.
This is not to say that aerobic activity doesn't provide any training benefit to your inspiratory muscles; it does, its just not sufficient to elicit the full potential of this vital group of muscles. The result is that under normal conditions, the breathing muscles never really get trained to cope with 'heavy breathing' and for this reason it will always present an uncomfortable challenge.

 

Breathlessness is a common feature of lung and heart disease, but as we know all too well, it's also a feature of normal exercise. Recent research has shown that the strength of the inspiratory muscles has a direct influence on how hard we can breathe and how breathless we feel whilst doing it.
If the muscles are weakened or fatigued (inspiratory muscles can fatigue by as much as 20%) then we can't breathe as hard and breathing requires greater effort; we experience the effort as breathlessness.
A useful analogy is to think about how much heavier a barbell feels on the 12th repetition than it did on the first. In the same way, if the inspiratory muscles are weakened or fatigued, breathing feels harder.

Even when the smaller physical size of women is taken into account, their lungs are still smaller than men's. Women also have narrower airways (breathing tubes), which means its harder to move air in and out of the lungs. At rest we breathe around 8-10 litres of air per minute, but during strenuous exercise a woman can raise this to around 120 litres per minute.
Compare this to an elite male athlete who can breathe as much as 240 litres per minute! Because women are unable to 'heavy breathe' as well as men in response to strenuous exercise, research has shown that many women may experience a drop in the amount of oxygen in their blood and a corresponding increase in their breathlessness.

 

Recent research evidence suggests that during heavy exercise, blood flow (and hence oxygen delivery) to the exercising legs is inversely related to respiratory work.
In other words, if inhalation is made harder by loading breathing with an added resistance, blood flow to the working legs goes down.
In contrast, if inhalation is assisted using a ventilator, blood flow to the legs goes up. What is more, the extra blood delivered to the legs can be put to good use by increasing the maximum power output. What this tells us is that the inspiratory muscles are capable of stealing blood from the locomotor muscles, and in so doing, they can impair performance.

Q: Which conditions can be improved by using POWERbreathe to reduce breathlessness?

Just getting older
Asthma
Emphysema
Bronchitis
Bronchiectasis
Cystic Fibrosis
Chronic and congestive heart failure
Heart-lung transplant patients (pre- and post-operatively)
Spinal cord injury
Neuromuscular diseases such as MS and Muscular Dystrophy
Obesity

Here are some other conditions where POWERbreathe users have reported improvements:
Snoring
Sleep apnoea
Speech disorders

Based upon our understanding of the response of the inspiratory muscles to training, a number of factors may be involved in the benefits to respiratory athletes:
training enhances the ability to inflate the lungs (you can take deeper breaths)
training enhances the ability to control the breath
training enhances the ability to sustain forceful breathing (your breathing does not become fatigued)
training may affect the intrinsic laryngeal muscles which control the action the larynx

If we make any muscle stronger, we improve the ability to control it (and the movement it creates) whilst it is operating under load. For example, consider your ability to undertake a task requiring fine control of your arm if it is weighed down by a heavy weight.
If you strengthen your arm by training, you will discover that your ability to perform the same task is improved as a consequence of your superior arm strength. Similarly, enhancing the strength of your inspiratory muscles improves the ability to control their activity under load, i.e., when they are contracting and overcoming the elastic recoil of the lungs and chest wall. Whilst this explains some of the potential benefits of POWERbreathe training, there may be something more specific occurring to the muscles of the larynx.

Basic anatomy and physiology of the larynx
The larynx is a complex amalgamation of cartilage and muscle.
During normal vocalisation, the pitch of the sound produced by the larynx is varied by the action of the vocal folds, whilst the loudness is varied by changes in respiratory pressure. The muscle that controls the tension of the vocal folds is the cricothyroid to find out more about the vocal folds .

The potential role of POWERbreathe training
When we breathe via an external resistance (e.g., the POWERbreathe) all of the muscles of inspiration are activated to an extent which is proportional to the size of the added resistance. It is reasonable to suggest that this also applies to the lateral cricarytenoid muscles, and to the other muscles that act to pull the vocal folds apart, including the cricothyroid. Certainly, there is a large movement of the larynx during loaded breathing that is readily observed externally. This being the case, training with POWERbreathe may enhance the ability to generate tension in the vocal folds and thus increase vocal range.

Our work with singers supports this notion as they report an improvement in their singing ability and that their voices feel "warmed-up" after using the POWERbreathe.

But isn't 'normal training' enough?
In common with physical athletes, respiratory athletes engage in specific training to maintain and enhance their performance. Our work with physical athletes has demonstrated that even in the highly trained international standard competitor, their inspiratory muscles are essentially untrained. This is because most of their training occurs at intensities of exercise that do not provide a training stimulus to the inspiratory muscles. Whilst this problem may not be quite so pronounced in respiratory athletes who engage is specific breathing exercises, our anecdotal reports suggest that they too can benefit from the 'super-enhancement' of inspiratory muscles performance which comes from training with POWERbreathe. For the respiratory athlete, POWERbreathe provides a unique stimulus to the inspiratory muscles, as well as to the smaller vocal accessory muscles. This stimulus cannot be produced without imposing an external load to inhalation, but the functional enhancement it stimulates may provide for enhanced capacity, endurance and range. Respiratory athletes have reported that training and warm-up with POWERbreathe provides something that they cannot achieve through any other means of training, practice or warm-up... Don't forget to take a look at the section on POWERbreathe warm-up

You should read POWERbreathe for fitness or performance to get the most from the following section.

At high altitude the air is 'thinner', containing less oxygen than at sea level. The higher we go, the thinner it gets. Climbing or skiing at high altitude place enormous demands upon the breathing muscles. In order to compensate for the thinner air, the lungs must work much harder, and exercise which at sea level brings on nothing more than a slight increase in breathing, can push your breathing to its limits at high altitude. At 3km (3000m) the amount of oxygen in the air decreases by 30%, and at 5km its half that at sea-level. This means that at around 1km you begin to experience breathlessness during moderate exercise, and at 4km you feel breathless at rest.

At sea level, your ability to exercise is limited by the capacity of your heart to pump blood to the exercising muscles. At high altitude, you become limited by the ability to pump air in and out of the lungs.

Just to put things into perspective: whilst resting at sea level, you breathe about 12 litres of air in and out of your lungs each minute. At the summit of Mt. Everest (8848m) it requires almost maximal levels of breathing (in excess of 150 litres per minute) just to put one foot before the other. This level of breathing can be sustained for only a couple of minutes at a time.

Human beings tend to 'learn' from experience what is an appropriate level of breathing for a given exercise task. When there is a mis-match between your previous experience and your current experience (as occurs at high altitude), you get a heightened sensation of breathlessness. Also, if your respiratory muscles are working very hard, they can 'steal' blood from the legs to meet their own requirement for oxygen, thus impairing leg performance. Finally, all that respiratory work can lead to chronic fatigue of your breathing muscles which also increases breathlessness and impairs performance.

By training with POWERbreathe prior to trekking / climbing at high altitude, or a skiing trip, you can prepare your breathing for the rigours of the increased work of breathing, minimise fatigue and breathlessness, and improve performance and enjoyment. Short of spending a few weeks doing lots of aerobic exercise at 3000m, there's not much else to rival POWERbreathe's ability to get your breathing prepared for the mountains!