ISLAMABAD: Breathing better isn't just for yoga any more, with top gyms across the US adding classes all about your breathe to their rosters.

Slowing down and controlling breathing has long been accepted as one of the best ways to lower the heart rate and keep us calm.

But with science on their side, coaches, trainers and exercise evangelists are pushing for breathing to become this year's fitness fad.

With its newfound uses, the old 'inhale, exhale,' is out, and using the right muscles to breath better is in - and it's harder work than it sounds, Dr Belisa Vranich, founder of The

When we breath properly, Dr Belisa says (center), our shoulders should not rise and fall, as she demonstrates to a client. She is one of a growing number of trainers that see diaphragm breathing as the key to building strength and avoiding injury

Dr Belisa - as she prefers to be called - is on the front lines of the breathing movement, developing breathing programs with the US Veteran's Administration and Equinox gyms, and coaching everyone from military personnel to average joes and competitive weightlifters to rethink one of their body's most basic functions. 
And according to her, we are all doing it wrong.
'Most of the time, people use their necks and shoulders, and those absolutely are not breathing muscles,' she says.
These are auxiliary, or secondary, muscles and should only be involved in breathing by providing support for the more core muscles.  Using our shoulders instead is what causes our shoulders to rise and fall with our breath, which Dr Belisa says they shouldn't do.
Instead, we should 'breath the way that animals breath,' with our lungs expanding and contracting in and out, in the middle of our bodies, says Dr Belisa.  
'Humans are the only dumb animal on the face of the planet that switches, after the age of five, to up and down breathing,' she says.  
Then you are 'taking a breath that is anatomically incongruous and is actually detrimental to our health.'
'Bad' breath can hurt our digestive systems, spine, ability to sleep and energy levels, she says.  and vertical breathing puts an unnecessary strain on shoulder and neck muscles, making them more vulnerable to injuries.
The secret to 'good' breath is all in the diaphragm.
The diaphragm is a large core muscle that sits just below the lungs and above the gut, 'like a flank steak the size of a Frisbee,' Dr Belisa says.
But we don't use this muscle because, 'culturally we're gut-suckers,' she says.
 Getting people to change their health habits is an absolute nightmare...but when you teach people about how they're breathing, they say they can't stop thinking about it
Dr Belisa, trainer, psychologist and founder of The Breathing Class 
When we brace ourselves with stress or suck in our stomachs, we are in poor position to use the diaphragm.
That really deprives us of some key advantages for both athleticism and mental health.
Diaphragm breathing has long been taught as a method to calm people because it stimulates the vagus nerve, which, in turn helps to lower levels of the stress hormone, cortisol.
Though she is a licensed and trained psychologist, Dr Belisa is equally interested in the physical benefits of breathing as she is in its mental health advantages.
'Stronger breathing muscles make for better athletic performance,' she says, and research as well as her experience bears that out.
Dr Belisa combines techniques taken from free-diving, yoga, martial arts and singing and makes them 'user-friendly,' she explains. 
Better breathing techniques allow the athletes she works with - including MMA fighters and  trainers at some of the most high-end gyms in the country - to develop better endurance. 
Dr Belisa says that many athletes 'hit a wall,' because their breathing gets too fast while exercising, but that they are able to break those barriers once they've done breath training.
Dr Belisa Vranich works with top athletes to improve their breathing and, in turn, their athletic abilities
While she teaches the muscular components of breathing, others turn their attention to carbon dioxide.
This basically boils down to holding your breath while working out.
'Hypoxic training makes you tolerate having different levels of CO2 in your body,' says Dr Belisa.
As our work outs intensify, our heart and breathing rate climb. As we quickly take in and use up oxygen, carbon dioxide also builds up in our system. The body treats it as waste, and the need to breath it out faster can tire us out.
So, building up a tolerance for carbon monoxide can also aid endurance training and weight lifting performances.
Together, better breathing techniques 'makes you able to work out harder and recover enough so that [you] don't hurt yourself,' more quickly, Dr Belisa says.
Better breathing can lead to more efficient detoxification of your body, she explains. 
'Most of us are very acidic, but when we breath better, we move the needle,' Dr Belisa says.
The build-up of carbon dioxide also lowers the pH, or acidity level of the blood.
Optimally, the blood should be at a neutral pH of 7.35, but 'most of us are walking around very acidic, under 6.5 or sometimes even under six,' Dr Belisa says. 
So the more we work out, the more acidic our pH becomes and 'your adrenals start working overtime to bring you back.  But that adrenal fatigue and acid reflux [that can come with it] get better right away if you start using your diaphragm to breath,' Dr Belisa says. 
She says that spending five minutes before and after any workout doing a breathing regimen can have noticeable effects on how you feel and your overall athletic performances.
'Getting people to change their health habits is an absolute nightmare,' Dr Belisa explains. 'But when you teach people about how they're breathing, they say they can't stop thinking about it, and I think it really resonates that you used to breath this way.'