Is Pranayama beneficial?

Pranayama (literally means 'lengthening of life') is a practice of yoga that focusses on breath control to improve health and wellbeing.

How does it work? Since our mood affects our breathing, hence we control our mood by regulating our breath. This is achieved by rhythmically performing inhalation and exhalation. In fact the power of meditation comes from its focus on breath modulation.

A number of scientifically conducted studies show that breathing techniques alleviate anxiety, stress, and insomnia while improving mood. In fact, cardiac coherence breathing exercises can stabilize [1] the heartbeat and have a powerful ability to dampen anxiety.

One recommended way to practice breathing technique is 365 method. At least three times a day, breathe at a rhythm of six cycles per minute (i.e. five seconds inhaling, five seconds exhaling) for five minutes. And do it every day, 365 days a year.

Reference: 

[1] https://www.scientificamerican.com/article/proper-breathing-brings-better-health/