Yoga taught in a public school is not a gateway to Hinduism and does not violate the religious rights of students or their parents, an appeal court in the US state of California has ruled.

An appeal court in San Diego on Friday upheld a lower court ruling that tossed out a family's lawsuit that tried to block Encinitas Union School District from teaching yoga as an alternative to traditional gym classes.

"While the practice of yoga may be religious in some contexts, yoga classes as taught in the district are, as the trial court determined, 'devoid of any religious, mystical, or spiritual trappings,'" the court wrote in a 3-0 opinion.

Stephen and Jennifer Sedlock and their two children had brought the lawsuit claiming yoga promoted Hinduism and inhibited Christianity.

They were disappointed with the ruling and considering their options, the AP news agency reported.

"No other court in the past 50 years has allowed public school officials to lead children in formal religious rituals like the Hindu liturgy of praying to, bowing to, and worshipping the sun god," attorney Dean Broyles said in a statement.

Paul V. Carelli IV, a lawyer for the school district, said there were no rituals occurring in the classroom and no one was worshipping the sun or leading Hindu rites. The district said yoga was taught in a secular way to promote strength, flexibility and balance.

Yoga is now taught at schools across the US, but the district is believed to be the first with full-time yoga teachers at all schools.

A three-year grant from the K.P. Jois Foundation, a nonprofit group that promotes Ashtanga yoga, provides twice-weekly, 30-minute classes to the district's 5,600 students.

About 30 families opted out of the classes, which began in 2011.