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HIITs and Hikes: A Fall/Winter Fitness Expedition

Classes at F45, an international fitness franchises with gyms in Longmont and Boulder…involve a full body cardio and strength workout based on High Intensity Interval Training (HIIT).

LONGMONT, CO — I entered the F45 Training gym at the corner of Longmont’s Hover St. and Nelson Rd., stepping out of the pre-dawn darkness and into my new routine. The days were getting shorter and the mornings colder in this autumnal time of year. This 5:30am class was the only time I could fit a workout into my hectic parenting/work schedule; this 45-minute early class made me break a sweat, then got me home in time for my kids’ school drop-offs.  

Classes at F45, an international fitness franchise, are geared toward “all fitness levels and ages,” and involve a full body cardio and/or strength workout based on High Intensity Interval Training (HIIT). Certified personal trainers lead the classes, which pump loud music (with a live DJ on special occasions) as each group works their way through a different daily circuit of exercises. This normally wasn’t my cup of tea—I’d rather avoid the gym altogether and just be outside, hiking by myself. Or the times when I did go to a gym, I was more of a loner, putzing around the free weights and hoping I was doing it right. But I also knew my 50-year-old body needed something more stuctured and effective if it wanted to continue being able to go on those hikes. Which I did.

Discovering HIIT

“High Intensity Interval Training, or ‘HIIT,’” explained Marlena and Dean Settle, the owners of F45 Longmont, who have been working in various fitness styles for 13 years, “involves exercises performed in repeated quick bursts at maximum or near maximal effort with periods of rest or low activity between rounds.”

Those bursts are typically 40 seconds or so, then maybe 15-20 seconds to rest between sets or to move to the next station (depending on the workout, or stage of the workout, as the work-rest intervals sometimes change with each set). The classes, I quickly realized, made me feel like I was training for the trails, which was my goal. I wanted to stay in shape and establish a base level of health while planning summer trips.

F45’s Longmont location on South Hover.

I’d driven by the generic vertical gym banner at F45 a hundred times before finally entering the building. It was the first gym I’d joined since before the pandemic and I’d never tried HIIT before; but by the end of September, the handful of classes I’d attended had me feeling that good, wholesome, all-body soreness. 

Concerns and Tracking

A hamstring injury in late September, during a fall in the backcountry, at the base of Pawnee Pass, interrupted my new morning gym routine for most of October—and reinforced why I needed to build my strength and balance! But when the bruising faded and I could come back in, the guidance of the F45 coaches, who knew about my injury, brought me back to full strength quickly. 

Researching what “the downsides of HIIT” may be, did indeed bring up important concerns: the biggest or which is understanding that this kind of workout is not for everyone. This is mostly because the “high intensity” part, namely that HIIT’s fast pace, can more easily lead to injury, and for some, can result in overtraining, fatigue, tendonitis, and burnout. I’d have to be careful. 

The gym hosts various 45-day challenges throughout the year, offering extra team training, motivation, and a nutrition component. When I tried a challenge last December, they provided me with a WHOOP fitness device, worn on my wrist at all times, in and out of class. It tracks heart rate, temperature, strain, and other metrics while also analyzing sleep and recovery patterns; it then breaks down strain, sleep, and recovery, and recommends when it’s time to back off a little. For me, this feature felt above my head as I’m not a professional athlete on some strict regimen; I just make sure to plan multiple rest days into every week.

Trail Training—what the ‘F’ stands for

The F in F45 stands for “functional,” Marlena and Dean said; the workouts are “designed to help strengthen functional, everyday movements.” Which is what I was looking for, specifically the movements involved with ascending passes and summits, sometimes with weight on my back. I’ve found several of these exercises in every workout—squats and lunges for the legs, deadlifts for hamstrings and back, stepping on and off a giant block with a sandbag across my shoulders for climbing muscle groups. 

I asked Marlena and Dean about the connection between their gym and the typical Colorado athlete. “We have many members who participate and compete in outdoor activities and sports. They love coming to F45 during their off-season to build strength and prepare for the next season. And then during their on-season, they continue coming to maintain that strength. Many members come to class during the week and spend their weekends hiking, cycling, running and [they have all told us about successes] with their sport—including increased strength and endurance during their races and events.”

They added, “the perseverance required to fight through to the end of a tough workout directly translates to the drive needed to participate in all of the outdoor activities that Colorado has to offer.” 

Results and Achievements

The author, center, red T-shirt, after a 45-minute class with a live DJ.
The author (center, red T-shirt) and that morning’s team, after a 45-minute class with a live DJ.

The transformation from my leg injury to recovery was swift, and now, the motivation to continue is high. I have not had a single zinger in my lower back (from an older herniated disk injury), which I used to get before beginning F45 workouts. This suggests that I’m building muscle around that injured lumbar area, which was one of my main goals. I’m also feeling strength in other areas of my body that have been neglected for years, and I’ve joined a community that cheers me on and high fives me when I complete a workout.

In this ongoing winter expedition that is my F45 experience—the planks, curls, cleans, and crunches are all steps toward a more resilient, capable body. If I’m to set any big hiking goals for next summer, like biting off another chunk of the Colorado Trail, or returning to the Pawnee Pass–Buchanan Pass Loop where I hurt my hamstring last fall, I’ll need to stick with a program like this. I cannot afford adventure without health.  Stepping into that gym from each cold, dark morning seems to be the gateway.

Joshua Berman is an writer based in Longmont, CO. His book, MOON COLORADO HIKING is coming out in April 2024. He did not receive any payment or compensation from any business or brand mentioned in this article.

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