© (Getty Images) Whether its hula hooping workouts or laughter yoga, the drive to get silly while getting fit has attracted a broader group of people.Competition at zany fitness events is occasionally fierce – but never stiff.

The moment Melinda Collings knew that she and her husband had to get back in shape arrived when the couple, just returned from the Caribbean in 2011, invited friends to their home and cued up pictures on their big-screen TV from their tropical vacation. “My husband and I had a very sedentary lifestyle. We would drink a couple of two liters of soda a day. We were very out of shape,“ recalls Collings of Port St. Lucie, Florida. “We saw ourselves in bathing suits, in the Caribbean, and it dawned on us – 'Oh my God, what have we done?'”

More motivated than ever to get in shape, the couple got a gym membership. Then a few months later, Collings saw an ad for Warrior Dash, a 5K obstacle course race, where participants slither through mud, climb over walls and combine all manner of other physical challenges with social camaraderie, some medieval costumes and a healthy dose of not taking anything or anyone too seriously.

While the masses converging on traditional road races – Boston, New York and Chicago marathons to name a few – speak to their continued popularity, another movement has emerged to combine fitness and frivolity on a grand scale. This extends from obstacle course races and The Color Run, where the untimed participants jog in rainbow poofs of color, to die-hard undead zombie runs and semi-clad Undie Runs. Quite literally millions have flocked to events that promote goofing off to get healthy.

For some, these events are just a break from humdrum runs, while for others, they become a way of life  – something that informs their training and sense of adventure and provides the offbeat jolt needed to get off the couch. “It was time. Everyone was getting way too serious,” says Dr. Pamela Peeke, spokeswoman for the American College of Sports Medicine, regarding the rise of foolhardy fitness events. “They were pushing themselves and losing sight of the fun and the satisfaction one gets by going out there and doing it.”

Peeke, who has completed a Warrior Dash, is no stranger to traditional running events, including marathons. But, then, as she and other veteran runners have long witnessed – frivolity never waited for an invitation, either. She recalls participating in the Marine Corps Marathon in the District of Columbia several years ago, with well over 20,000 hardcore runners – many, religiously checking their watches to stay on track with time goals. “But every now and then, you’d see somebody run by and they were dressed in an Abe Lincoln costume ... it was a scream,” Peeke says. While running in a Boston Marathon – the premier 26.2 on the American circuit and a major draw for elite runners – she recalls: “Some guy was juggling balls while he was running. I'm not joking.” Another man donned a Superman costume, complete with a cape. “I was dying. And do you know by the time I stopped laughing and just got into it, I’d already run another two, three miles – I’d already hit another 5K,” Peeke says. “So, what it really does is it evokes a feeling of childlike pleasure. We as adults need to play more. We need to play a lot more.”

Quite literally – both mentally and physically – experts explain that play loosens us up, which can actually be protective against injury as well as allow us to challenge our bodies and minds in new ways. Think about the kid contorting himself on the monkey bars without a care in the world – and doing it all expertly. “You can either be joyful or you can be stressed,” Peeke says. [But] the human brain can’t do both at the same time. It’s impossible.” When we're joyful, stress hormones decrease. “When they do that, you have lower levels of inflammation throughout the entire body, and you actually loosen up enough so that your level of injury actually should decrease," she says. "Because people injure themselves when they get too stiff.”

From hula hooping workouts to laughter yoga, the drive to get silly while getting fit has made the playing field more inviting to a broader group of people, including those turned off by more serious, competitive events. Organizers of races like the Warrior Dash are quick to point out that all participants, including hardcore athletes, still have the opportunity to push their absolute limits. And, they add, the offbeat fitness offerings haven't sapped the popularity of traditional events; instead, they seem to supplement those. “Fun, laughter, enjoyment, joy – all of those things really need to be infused in all of these endeavors,” Peeke says. “I am absolutely thrilled and happy, [as are] all of my colleagues, when we see that in a lot of these kinds of competitions.”

Not that there aren’t limits, or instances in which frivolity overtakes fitness for the win, to the detriment of participants' waistlines. Enter doughnut-downing running events, where people are challenged to eat prodigious amounts of pastries over the course of a few miles. Then there's "hashing." That’s where you run and drink alcohol, and either your running club has a drinking problem – or your drinking club has a running problem.

“Hashing is huge internationally,” says Pete McCall, spokesman for the American Council on Exercise, who is also an ACE-certified personal trainer and a professor of exercise science at San Diego Mesa College in San Diego. A rabbit – or a fast runner – marks the course for the club and drops off stashes of beer along the way. Then the club, whether in the U.S. or abroad, partakes by running and drinking. “A lot of expats, when they’re overseas, will form hashing clubs, to combine social time with activity time,” McCall says.

For those who are in reasonably good shape and run to keep it that way, such events may help break up the monotony, he says. But they're not a replacement for going out and running, say, three miles regularly – without imbibing – just a supplement to mix things up.

He can see people doing just about anything purely as a goof. But whether downing beersor putting back pastries on the run, he says, if the object is to lose weight, you might want to seek out a more goal-aligned folly. In other words, don’t kid yourself. “Because if you have a serious weight-loss goal [or are] struggling with weight issues … then doing an activity like that certainly wouldn’t be advisable because you’re going to go into a caloric surplus and add weight,” McCall says.

However, on the whole, McCall is pro-goofing off and getting social and active at the same time; and, like Peeke, he sees serious benefit in all the hilarity. For starters, he notes, the same old grind isn’t optimal for body or mind.

“There are people that lift weights way too frequently. There are people who do yoga too often, and the body likes moderation ... it likes variability,” he says. “It doesn’t like too much of one thing. It doesn’t like too many doughnuts. It doesn’t like too much alcohol. It doesn’t like too much exercise. Your body will even shut down if you drink too much water.”

He also sees brain and body benefits in the unique challenges, like those found in obstacle course races, in which he also participates. “You’re developing really important motor skills. And, here’s something’s that’s really cool: Any time you learn a new movement or any time you learn a new skill, you’re enhancing the wiring in your brain,” he says.

For Melinda Collings, all the hard work she’s put into play has helped her shed about 40 pounds, and she says her husband, Eryk, has dropped around 50. Though their weight fluctuates, she says the result has undeniably improved their shape and fitness. "We have so much more strength and we can accomplish so much more," she says. It’s also sparked the couple’s sense of adventure as well as an active lifestyle. "Now we go surfing and we go mountain biking and we go hiking and we do so many more things."

Next up: Collings says they are in the process of selling their home and buying an RV. “So we can travel around and explore and hike and bike and do obstacle course races all over the U.S.,” she says. To finance their dreams, she has the capacity to work remotely and he has skills, like being a mechanic, that will allow him to work on the road. “We literally used to go to work every day and we would come home and we would sit on the couch and we would watch TV. Now we just do all of this awesome, crazy stuff and we get to meet so many of these awesome, crazy people.”