GLEN HELEN -- Carlos Luna's heart pounds and his chest aches. His legs and arms burn from exertion. While this may seem like torture, Luna regularly submits himself to this pain all in the name of fun.

Luna is a mudder: A person who participates in races which feature obstacles and a lot of thick and sticky mud.

"It's just a great challenge and a lot of fun," said the 35-year-old father of two who hails from Fontana. "When you're done you feel a real sense of accomplishment. "

Luna is gearing up for what he calls one of the most challenging mud runs on his race circuit, The San Bernardino Sheriff's Department Mud Run.

"I've been doing mud runs for about four years, and I do about four or five every year and I have to say the sheriff's one has one of the most challenging courses because you're running the course that the cadets have to go through when they're in the academy," he said.

This year the Sheriff's Department will host the ninth annual run on Saturday at the sheriff's Training Center at 18000 W. Institution Road, behind the Glen Helen Rehabilitation Center.

Participants run a 5K course and have to tackle a variety of obstacles including walls, mud pits, low crawls and tackling a steep hill all while covered in mud.

Last year nearly 3,000 people accepted the challenge and tackled the course. Among those who participate are trained SWAT members from various law enforcement agencies, former and current members of the military and people who want a good physical challenge, sheriff's officials said.

This year the Sheriff's Department is partnering with the San Manuel Band of Mission Indians to help promote fitness and to help fight childhood obesity.

The mud run has long hosted a 1K mud run for children up to age 13. The children's course also includes obstacles and a lot of mud, sheriff's officials said.

"My kids have been doing the kids' run for the last three years," Luna said. "I mean what kid doesn't want to get dirty without getting yelled at by their mom? "

Over the last three decades, the rate of childhood obesity has more than doubled, according to the Centers for Disease Control and Prevention.

That trend is mirrored among Native American youth, San Manuel officials said in a written statement.

"San Manuel and San Bernardino sheriffs hold that healthy communities are made up of healthy individuals," said Chairperson Carla Rodriguez with the San Manuel Band of Mission Indians in a news release. "Events like the mud run allow individuals of all ages to train and prepare for this challenging, yet fun, race supporting overall healthy living. "

Since the beginning, the sheriffs' mud run has raised money for various local charities including the sheriff's Gift of Love Program which provides toys for needy children during the holidays, Option House Crisis and Prevention Services which helps families experience violence in the home, San Bernardino Sexual Assault Services and the Sheriff's Employee Assistance Team, the same organization that provided help to the families of fallen sheriff's Detective Jeremiah MacKay and wounded Deputy Alex Collins,

Luna registered his five-person team and persuaded his wife, Angelina Luna, to join in the run this year. "He does them and the kids do them so I decided this year I was going to try," she said. "I'm not going to lie, I'm nervous about it, but I can't wait to meet that challenge. "

The cost to register as an individual is $40. A team of five can register for $175 and children can participate in the 1K for $15. Registration closes on Tuesday, but those still looking to participate can register the day of the event for $50 for individuals and $225 for a five-person team. The children's price stays the same.

To register online, visit sbsdmudrun.com