Lisa Fierer, with Rocky Mountain Paddle Board, leads a Standup Paddle Board Yoga class at Boulder Reservoir in Boulder, Colorado July 7, 2014. Boulder Daily Camera/ Mark Leffingwell

Instructor: Lisa Fierer, of Boulder, who has been teaching yoga for more than seven years and had a background in white-water kayaking and competitive rowing. Fierer discovered stand-up paddleboard yoga a few years ago. The is the first full year Rocky Mountain Paddleboard has offered SUP Yoga regularly.

The response has been huge. Many classes sell out.

“In Boulder, we’re such an adventure-driven community of athletes and outsdoorspeople, and the merging of yoga, which is typically done inside, and taking that onto the water outside is appealing,” Fierer says.

What is the workout? A class that fuses stand-up paddleboarding with yoga.

First, we received instruction on land, learning about the board, paddle, various strokes and turns. Then we took our boards out on the reservoir and paddled to another area of the water. We “anchored” our boards by dropping a heavy bag attached to a rope and then did a slow yoga practice while balancing on the boards.

What’s different? You’re doing yoga postures on an unstable surface, so you have to really balance and focus.

Fierer says the board “highlights where our natural imbalances are, so we have to recruit our ability to center and stabilize, both mentally and physically.”

And because it’s on the water, your practice is affected by the wind, boats, slight waves, bugs, sunshine and the natural elements.

“It helps to have a lighthearted approach,” Fierer says. “If we fall, we fall in the water and that can be fun and invigorating.”

And cooling. Those boards get hot. Toward the end of class, I felt like I was standing on a piece of tin foil. I kind of wanted to fall in.

SUP Yoga is more informal than yoga in the studio, although my class did have a short vinyasa flow.

Some postures are easier on the board, whereas others are harder — like Warrior 2, which I found nearly impossible. Some people find inversions easier on the board, because “people can tap into a level of courage and openness to try things they may not be open to trying in the studio,” Fierer says.

The relaxation poses tend to be deeper, as the water lulls your body, she says.

But you have to move slowly and carefully, and beware of where you have placed the paddle, or you might knock it into the water.

Rocky Mountain Paddleboard provides all equipment, but if you’re new, pick a wider board (that’s easier to balance on) or one specifically designed for yoga, with a sort of yoga mat affixed to the surface that helps with grip.

Cost: A drop-in is $35, which includes the equipment and at least a 75-minute instruction, often two hours.

This isn’t a bad deal, considering normal board rentals with no instruction are $20 per hour.

You also have to tally in entrance to the park: $6.25 to Boulder Reservoir and $8 per car to Union Reservoir in Longmont, where classes are also offered.

Level: All levels, even if you’ve never done yoga or SUP before.

The hardest thing about class is the concept of practicing yoga on a board floating in the water, Fierer says.

The class can benefit people with balance issues, because it will simultaneously strengthen and challenge your balance.

As Rocky Mountain Paddleboard gets more repeat students, it will also begin offering classes for more experienced students, as well as a yoga sculpt class with training on the land and more intense postures on the board.

“A lot of people have questions at first, trepidation about how is this done? We encourage people to come out and try it. Everyone who’s tried it has found it far more accessible than they would have thought — even people who don’t have a lot of experience with yoga,” Fierer says.

When:10-11:30 a.m. Monday at Boulder Reservoir; 10-11:30 a.m. Fridays at Union Reservoir; and alternating 9-10:30 a.m. Saturdays at each location.

What to prepare: Swimming suit, yoga shorts on top if you want, a water bottle, towel. Life jackets provided. Arrive about 15 minutes early. 

Muscles worked:Full body, with an emphasis on the core and stabilizing muscles.

What I loved: The mental challenge of knowing my balance was the only thing keeping me from falling into the water — and succeeding. I can’t swim, and have had a lifelong fear of water, so if I can enjoy this class, anyone — seriously, anyone — can do it.

I quickly conquered my anxieties, due to the fun, low-pressure, noncompetitive atmosphere and summer sunshine, and there were moments when I forgot I was on the water at all. Plus, there’s something amusing about doing boat pose on a boat. Yoga fits well with the outdoors and should be practiced there more often.

Checking this off my bucket list is my equivalent of sky-diving for most people. It was a pretty big deal for me.

What I didn’t like: Due to my inability to swim, I kept my life jacket on the whole time. It made some of the postures awkward, especially the twisting moves. But I am amazed I was able to do it at all. 

Also, our class coincided with lawn-care maintenance time at the res, which meant someone was mowing the grass nearby throughout the entire class. That’s the risk you take when you go outside, though, right?

How I felt after the class: Paddling back, I felt totally different than when I first got on the board. The yoga calmed my brain and body, and the paddle back to shore was peaceful, serene and joyful.

— Reported by Aimee Heckel.