Fortunately, we don't need to think much about breathing – it is automatic – our body handles it. Inhale, exhale, inhale, exhale, all on a routine. It's not just that routine that is automatic though, also the rate at which we breathe is controlled without us even thinking about it when our body needs more oxygen than usual. So, for example, during sporting activities, our breathing rate increases automatically too.

"It's a vital process that takes place subconsciously," said Barbara Nützel, an instructor at a school for health management in Saarbrücken, Germany.

This way, the body prevents going into oxygen debt, a temporary oxygen shortage in body tissues resulting from intense exercise. Our cells need oxygen to break down glucose and produce energy.

Is it possible to boost athletic performance by modifying your breathing?

First, some background: "Breathing is regulated by the autonomic nervous system and brainstem," said Sylvain Laborde, a researcher in the performance psychology section of the Cologne-based German Sport University.

The brainstem respiratory network can adapt our breathing to external circumstances. For example, when relaxed or asleep, we automatically tend to breathe deeply and evenly.

"Our body fine-tunes its oxygen supply," Laborde said. "We have sensors, so-called chemoreceptors, that recognize whether we have sufficient oxygen – and not too much carbon dioxide – in our blood and adjust intake accordingly."

But not all breathing is the same. For example, we can take air into our chest or seemingly bottomless into our belly. The latter is called diaphragmatic breathing, also known as abdominal, stomach or deep breathing.

The diaphragm is a large, dome-shaped muscle at the base of the lungs. When you breathe diaphragmatically, inhaling makes the diaphragm contract and move downward, which creates more space in your chest cavity and allows your lungs to expand.

When you exhale, the diaphragm relaxes, moving upward in the chest cavity and forcing air out of your lungs.

We're born knowing how to breathe diaphragmatically, said Nützel, but unlearn it as we grow older. So stress is one reason our breathing becomes shallower.

"Chest breathing wastes energy," Laborde says, "as it activates many muscles we don't really need for breathing." In addition, breathing this way during sporting activity reduces the energy at our disposal.

Athletes would therefore do well to learn the diaphragmatic breathing technique and practice it regularly. According to Laborde, it can bring their breathing rate down from 15 to 20 breaths per minute to six.

It can also be worthwhile to attend a yoga class, where the emphasis is placed on diaphragmatic breathing training, said Nützel, a yoga instructor herself.

Athletes can breathe either through the nose or mouth. "No matter what the sport," Laborde said, "it's best to breathe through your nose because the air is then moister and warmer," which protects the respiratory passages from drying out and cooling down.

It also protects them from dirt, Nützel said, since "the nose acts as a natural filter for airborne particles."

During intense athletic activity, however, it's normal to breathe through the mouth to meet the body's oxygen requirements. "At high intensity, you need a lot of oxygen, so sometimes you've got no choice," said Laborde. "If oxygen intake through the nose is too low, your performance suffers."

Which breathing technique is best for jogging or strength training at the gym? "Whatever sport you do, the point is to require as few breaths as possible," Nützel said.

When we run, there's no need to consciously adapt our breathing to our strides. "It's best to give your breathing free rein," noted Laborde, "because our body knows exactly how much air it needs."

For strength sports such as weightlifting, on the other hand, a targeted breathing technique is proper. "You should exhale as you work against gravity and inhale again in the relaxed phase," advises Nützel.

A well-known breathing technique during weightlifting is called the Valsalva maneuver. "Athletes try to mobilize more strength by pressing air against their closed mouth and nasal passages," noted Laborde, but adds that it makes little difference in their performance.

Practicing yoga is a good way to increase your respiratory volume. "You learn to breathe more deeply, and with a little training, you'll need fewer breaths to reach the same volume," Nützel advised.

Breathing efficiently doesn't only boost athletic performance by supplying the body with an optimal amount of oxygen. "Conscious breathing strengthens the immune system as well," remarked Nützel.

What's more, she said, exhaling more slowly lowers blood pressure. Your heart rate – and resting heart rate – decrease.

Breath training can also have positive psychological effects, such as stress reduction. In addition, by breathing more mindfully and slowly daily, you enhance your performance capacity and your quality of life too.

Laborde recommends integrating slow breathing into your evening routine as a relaxation technique. "Over time, slow breathing is beneficial to health and advisable," he said.