This elite police force guards the Himalayas -- and also practices yoga

Members of the Indo-Tibetan Border Police practice tree pose during a yoga class in the Himalayan mountains.

(CNN)Members of the Indo-Tibetan Border Police wear military fatigues, with thick boots and heavy jackets. On the job, they guard the vast border between India and China, where the mountaintop temperature can drop to minus 50 degrees Fahrenheit. Outside their regular duties, they summit Mount Everest.

They also practice yoga.
In remarkable locations virtually inaccessible to the rest of the world, these "Sentinels of the Himalayas," often in full military gear, train in one of India's most renowned and ancient traditions as part of their well-being regimen. Their routines include physical and mental exercises, as well as breathing techniques that help members acclimate to the high altitude, which ranges from 9,000 to 18,000 feet.
Members of the Indo-Tibetan Border Police practice yoga on a frozen lake in the Himalayan mountains ahead of International Yoga Day.
Now, the elite police force -- along with yogis around the globe -- are marking Thursday's fourth annual International Yoga Day, which aims to raise awareness of the many benefits of practicing yoga.
India proposed the holiday in 2014 at the United Nations. With support from 175 other member states, the UN General Assembly passed a resolution proclaiming June 21 as the International Day of Yoga.