The Jukestir – Bonneville Academy teacher, Brad Evans, designs unique punching bag

February 02 23:04 2023

Originally intended to train martial artists, an unpredictable punching bag designed by a Bonneville Academy teacher has spread like wildfire and ended up in some unpredictable places.

Brad Evans, a history teacher at Bonneville Academy and an avid sports fan, created the world’s first unpredictable punching bag after pondering a question he had about fitness and preparation.

“My buddy and I were both into soccer and martial arts,” Evans said. 

“He was in better shape for martial arts and I was in better shape for soccer,” he went on to explain. “So I thought ‘How is that possible? Why am I in better shape for one sport and he’s so relaxed and doesn’t get burned out in the ring?’”

Evans did some research and found a concept Bruce Lee called “neurophysiological adjustment.”

“It’s the concept that your brain controls all of your muscles,” Evans said. “If you can relax when you’re under pressure, you’ll use less energy and be quicker. I thought, ‘How do you train that?’ I had this moment where I was like, ‘Ah ha! You need an unpredictable punching bag —  a punching bag that moves out of the way.”

Evans wasted no time after his big idea. He headed to Home Depot and purchased some rope, foam, and weights, and put together his first unpredictable punching bag in his garage.

Unpredictable because unlike other punching bags, Evans’ bag responds in a random manner, never reacting the same way twice.

In the early stage of his invention, Evans sent his design to Ultimate Fighting Championship fighters. They loved the idea, according to Evans.

“Unpredictable motion makes you faster,” Evans said, talking about why UFC fighters loved the unpredictable punching bag. 

Cal Dietz, an Olympic Coach, told Evans he loved the design. 

“‘Jukestir is not sport specific because the skill is brain speed, and that helps you learn other skills faster,’” Evans said, quoting Dietz. “He said, ‘It trains essential and fundamental skills. I like it.’”

The unpredictability trains both the mind and the body to see, think and react.

Evans also sent his new punching bag to other sports teams, including football teams and baseball teams. 

A college football team that planned to use the punching bag to train linemen was pleased with the technology. To Evans surprise, the college used his punching bag for rehabilitation.

Evans also sent his bag to a baseball team.

“They tested it to see if it helped their infielders reduce their errors, because the ball can pop up unpredictably, just like this bag can move unpredictably,” Evans explained. “They tested it with their hitters because the spin rate on the baseball really affects whether you can contact it or not. If this bag has a spin to it and you hit it, will that result in more hits?”

Even though the punching bag is ultimately designed for martial artists, Evans took his design to police officers and SWAT team members all over the country, including those in Los Angeles and Chicago for testing

“The police officers taught me about something where you observe, orient, decide, and act,” Evans said. “It’s a military term that talks about how if you can process and react faster, that has a lot to do with victory. I became obsessed with getting this bag to move like a real person.  … A lot of police officers are interested in this, because if someone reaches in their pocket, is that a gun or is that a cell phone? You don’t want your brain to rely on previous information. You want your brain to rely on incoming information. The way you do that is by training unpredictable motion, like the bag.”

After sending the punching bag design to police, SWAT teams, UFC fighters, and sports teams, Evans worked on perfecting the punching bag from the ideas and feedback he received, which meant buying more foam, weights, and rope.

“I was making it in my garage and taking it around to many people, and I finally got some leg roller foam, which is pretty nice foam, and I put it together with some other parts,” Evans said. “It was a mix of homemade and professional. … You’ve heard of a sweat-shop? Well, I was freezing in my garage putting these bags together.”

After improving the punching bag, Evans’ ideas fell into the hands of several neuroscientists who used it for something unexpected.

“It turns out there is a link between coordination and cognitive function,” Evans said. “One of the first gifts we give our babies is a mobile, because it moves around the crib and the baby can look, see, think, process, react, and try to reach up at it.  … The beginning of all of our fitness training was in the crib. … That’s what this is. It’s a punching bag but it’s starting to become something more. It’s an adult mobile. … It has to do with neuromuscular stretching.”

Before Evans knew it, his punching bag was being used by individuals with Parkinson’s and Alzheimer’s to improve their cognitive function.

“I just invented this for boxing,” Evans said. “People keep coming out of the woodwork asking if I’ve tried it for this and for that … I think if it would have just been for boxing, it would have been hard for me to take such a leap of faith. … I recently received an email from a doctor who said he used the bag for his patients with Parkinson’s and all of these disabilities and he said it was the best tool he had.”

Evans started to sell his design on Amazon with the name “CorBag,” short for coordination bag. He sold on Amazon for three years. At the peak of his selling, he was receiving 50 or more orders a day.

“I sold so many punching bags, I had to shut it down,” he said. “I couldn’t keep up with the demand. I couldn’t make that out of my garage.”

Evans began looking for a company to help him make and sell more bags and to help him perfect the design.

“There was a company called Onyx360 in Salt Lake City and they had some engineers who worked on it with me and had it professionally manufactured,” Evans said. “Now, everything is custom. The weights are custom, the foam is custom, and the shape is custom. … The bag is a blend of a circle and a square, because that’s going to challenge your brain more. Your brain knows what a circle is and it knows what a square is, but this shape builds the brain.”

Now, fast forward 10 years later, Evan’s perfected design was completed in October 2022.

“There is a lot of science that went into this to make it this way,” he said.

He named his final design “Jukestir.”

“Juke means to move out of the way, like if you are playing football and somebody jukes you, they deceived you and moved out of the way faster than you could respond,” Evans said. “Stir can mean to combine two things, like stirring a bowl. In this case you are combining your body and brain.”

Since the launch of the perfected design in October 2022, Evans has sold over 100 bags.

His design is still being used by doctors, neuroscientists, sports teams, first responders, UFC fighters, and in gyms.

Evans plans to market his Jukestir to more sports teams. He also plans to come up with more inventions and to sell them.

“I have a ton of stuff, like a camouflage pattern that no one has thought of,” Evans said. “My garage has 50 ideas hanging out in it, but probably one or two of them are good ideas.”

Evans encourages others to pursue their dreams of invention.

“If you believe, you can succeed,” he said. “I didn’t know where this was taking me, but the journey of a hundred miles begins with the first step. I just kept going one step at a time and I never gave up. I kept pushing and eventually the pieces fell into place. I definitely want to encourage everyone out there, if they have a dream or an idea, they can do it.”

His unpredictable Jukestir is a hit, but Evans continues to teach history at Bonneville Academy in Stansbury Park. He has been teaching for six years. In 2021, he was nominated for teacher of the year for his work at Bonneville. 

In his free time, Evans enjoys fly fishing and spending time with his wife and two children.

To find out more about Jukestir visit The bag is also sold on Amazon with free shipping and a 10-year warranty.

“This bag seems like it will last forever,” Evans said. “I’m really excited for what the future will bring.”

For more information, please visit

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Company Name: The Jukestir
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