Jogging on the beach, military crawls and leapfrog in the sand make the TRX Boot Camp class quite a challenge. As if those TRX straps weren’t intimidating enough.

The TRX system, developed by a former Navy SEAL, is often referred to as suspension training. The TRX nylon straps are designed to use your body weight and gravity to create resistance. They can be attached to any elevated fixture, including a door or tree branch.

Instructor Eden Monteilh began the class with a quick warmup jog around Ewa Beach Park, followed by some pushups and dips. She tailored the exercises based on each individual’s fitness level and experience, providing modifications when needed.

The TRX straps take some getting used to. First, when you are holding onto the handles and leaning forward, it’s hard to trust the ropes. And the movements look simple but they definitely are not.

In between the TRX workouts, numerous circuits were set up to keep participants on the move. The first one included lifting a 30-pound sandbag suspended from straps over your head while leaning forward. Others included a Rip trainer, a lever bar attached to a resistance cord that was wrapped around a tree (you hold the bar like a canoe paddle and perform a paddling motion with the cord providing resistance); heavy ropes; an assisted pull-up station (the assistance didn’t help me much); kettlebell lifts and stretches.

Each circuit was set up to push yourself to your limits. Modifications could be made, such as doing a jumping squat versus a traditional squat. When using the heavy ropes, we could opt to stay in one place, swing one rope at a time or swing both and run from side to side through the sand.

The workouts change from class to class, so participants say boredom is not an issue.

The training is intended to condition from the inside out, according to Monteilh.

"Your core (abs, back, thighs) is your powerhouse. If you get that strong, all other movements are easier, faster, stronger," she said. "Strong joints are also vital for sports performance and everyday movements. The goal is to get people stronger for their everyday life and their sport."

Because suspension training is low-impact, it is used in rehab and can strengthen joints, explained Monteilh, noting that’s why so many athletes use it.

"My class moves you, how you move in daily life or in sports. Meaning, you move in multiple directions and planes. We don’t overuse the same muscle group or repeat similar movements over and over, creating overuse injuries," she added.

Monteilh warns participants not to eat within 90 minutes of class to avoid nausea. After making it through one TRX Bootcamp session, I agree that’s sound advice.

Moms can bring their kids along if they are old enough to play in the park during the workout.

Class ended with a good stretch, but my muscles were still crying later in the day and into the next morning.