On the longest day of the year — the summer solstice, June 21 — International Yoga Day celebrations swept nearly 200 countries, as those in the Northern Hemisphere greeted the first day of summer.

The day also represented a spirit of peace and good will, Indian Prime Minster Narendra Modi said to a crowd of more than 35,000, before taking to his mat and joining what's been billed as the largest yoga demonstration in history.

Modi also mentioned the health benefits of the ancient Indian practice. Studies have shown it eases conditions such as chronic pain and high blood pressure. “Practicing yoga helps combat stress and chronic conditions.” Modi said, The New York Times reported.

Yogis flowed in Times Square, meditated under the Eiffel Tower and om'd in Madrid's Colon Square. Together, hundreds of thousands greeted the sun — an important part of any energizing yoga practice.

“In traditional yoga philosophy, the sun is related to a more masculine, fiery energy … whereas the moon is associated with a more feminine kind of calming, soothing energy,” Erin Taylor, founder and head coach of Jasyoga in Seattle and London, told weather.com. “Ultimately it's about balancing these two energies, and yoga is an incredibly powerful practice for helping us strike and sustain that balance.”

Dana Flynn, the founder and director of Laughing Lotus in New York and San Francisco, agreed that the longest day of the year — and summer in general — has meaning.

“The light is a metaphor for lighting our lives and staying on a path,” she told weather.com. “[Yoga] is a celebration of light; it's a celebration of togetherness; it's a celebration of happiness. We get these beautiful ways to be happy [with yoga] even in the midst of really difficult stuff going on in our lives.”

Flynn participated in the Times Square celebration as well as a festival, Wanderlust, in Vermont. She said she's still on an emotional high from kicking off summer in this way.

“There's a real opportunity to practice with the seasons and practice with the different time of day that really can be really beneficial,” she said.

A more intense, warm yoga class on a cold winter's day or in the morning can provide a burst of energy. A restorative, cooling session when it's hot outside or at night can cool the body, providing balance, she explaned.

The International Yoga Day celebrations also served as a reminder to get outside for your health this summer, with yoga or without.

“It's a great time of year to just get out, get outside and get excited and energized about moving your body no matter what activity you choose,” Taylor said. “Whether it's yoga, or running or cycling or swimming, this time of year is about getting outside and celebrating.”

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