The plumber of hybrid racing
Ian Hosek is a champion obstacle course racer and a professional endurance coach. He now coaches elite Hyrox athletes, including Vivian Tufuto, who finished third in the 2024 Hyrox World Championship.
The Hybrid Letter talked with Ian about overtraining, building a real aerobic base, and the role of high-intensity work in an effective hybrid program.
This interview has been edited for length and clarity
The Hybrid Letter: Were you always into competitive sports?
Ian Hosek: I've done competitive sports my whole life, though they’ve shifted over the years. Growing up, I played soccer, hockey, tennis, and did some mountain biking. I wasn’t really into running or strength training, the things you'd typically see in the hybrid world. My journey eventually took me to OCR (obstacle course racing) in college, where I started running races recreationally and found I was pretty good at it. OCR was this blend of strength, running, and fitness, which became my career for a while. Then, as hybrid racing started gaining traction, my understanding of the human body and the direction athletes wanted to go led me to shift some of my training and coaching focus to the hybrid space.
THL: What sparked your interest in coaching?
IH: I’ve always loved sports science. Growing up, I thought I’d become an architect, then shifted to engineering for renewable energy. But after school, I gravitated more toward sports science and physiology, which had always been my passion. I even worked at Nike for about four and a half years, where I got to learn from some of the best physiologists and see the mechanical side of things like shoe testing. Eventually, I realized I knew a lot about training and started coaching on the side while at Nike. It fulfilled me more than the corporate world, so in 2016, I went full-time with my coaching business and haven’t looked back.
THL: How would you describe your training philosophy?
IH: It’s very individualized. Many athletes come to me overtrained, so the first step is often resetting and addressing any lingering fatigue or soft tissue issues. From there, we can build volume safely.
I primarily use heart rate training for aerobic sessions, with RPE (rate of perceived exertion) for high-intensity work. Athletes often find that when they’re working in aerobic zones, it feels slow at first, like they’re barely moving. But that’s exactly why it’s effective. Building an aerobic base takes discipline.
With each athlete, once we hit certain volume levels, we have a conversation. There’s a point, typically around 10-11 hours of aerobic training a week, where we decide if more volume is necessary. Going beyond that is usually reserved for pro athletes without 40-hour workweeks or family obligations.THL: What types of athletes typically reach out to you?
IH: It’s a mix, from recreational racers to World Champions to marathoners looking to improve. Many have been injured by past training. My goal is always to make them healthier and happier in their sport. Often, though, they come to me having pushed too hard, so I help them reset, which includes rest and deload weeks. For female athletes, we even time recovery weeks with their menstrual cycle, which science shows can help reduce injury risk.
THL: When athletes come to you with injuries, what’s your approach?
IH: It depends on the injury. I’ve had my share, so I’m familiar with both prevention and recovery strategies. For larger injuries, like stress fractures, I don’t start with them until they’ve healed. With soft tissue injuries, we can start carefully and build up from there. Physical therapy is key—doing the exercises properly is critical to prevent recurring issues.
THL: What’s your approach to rest and recovery?
IH: I mandate one rest day per week. It can include a light walk or easy activity but not a HIIT session or a long hike. You need that time for your body to adapt to stress and recover. I generally structure two high-intensity sessions a week, with other aerobic training and strength work layered in based on their schedule and needs.
People often race too much, which can interfere with training gains by cutting into recovery. For peak performance races, I recommend spacing them about six weeks apart to allow for a taper, recovery, and then a full training block. If they want to race more frequently, we approach it with shorter tapers and adjust training accordingly.
THL: What are some common mistakes you see with hybrid athletes?
IH: Many think they need to be at 100% intensity all the time. Hybrid athletics, like Hyrox, is an endurance sport, meaning most training should be aerobic. High-intensity work has its place, but it’s the aerobic base that builds efficiency and endurance for these longer events.
Running is ideal since Hyrox races are largely running-based, but I adapt for athletes with past injuries by incorporating low-impact options like the SkiErg, rower, assault bike, or indoor cycling.
THL: Do you also coach athletes on the mental side of racing?
IH: Yes, though my specialty is endurance and running. I’ve worked with a sports psych coach myself, which was incredibly valuable. Mental coaching often involves pacing, managing expectations, and not comparing yourself to others. Most athletes perform their best when focused on their own race, not on others.
THL: How do you help athletes bounce back from a tough race?
IH: We do a race debrief to discuss what went well and what didn’t. If they struggled on a particular station, like lunges, we’d add that into their training and review what led up to it—maybe they went too hard on the run before. If it was more mental, we work on strategies to stay positive, like using mantras tailored to different points in the race.
THL: Why should someone hire a coach?
IH: For the same reason you’d hire a plumber if you don’t know plumbing. Training may seem straightforward, but a coach brings knowledge, objective insight, and expertise in sports science. Coaches help maximize performance while balancing other life factors, like stress. It’s about guiding athletes safely to reach their full potential.
THL: Are there exciting races for you on the horizon?
IH: I’m taking a bit of a break. This season had its challenges, and I’ve been dealing with some life stress that affected training. But with winter here in Idaho, I might do some cross-country ski races or a few local events.
You can follow Ian on Instagram or learn more about working with him as a coach.
Science Corner: There is nothing magical about Zone 2
There is a lot of talk about Zone 2 training for endurance sports. And for good reason. It is a big part of a training program for any successful athlete. A new academic study in Sports Medicine provides important insights into why Zone 2 training works.
Endurance athletes seek to increase muscle mitochondria, the part of our cells that produce energy. If you have more mitochondria, you can produce more energy more efficiently. So, what kind of training increases your mitochondria the most?
Surprisingly, the study found that "sprint interval training" — pretty much the opposite of Zone 2 training — was the most efficient way to increase mitochondria. An hour of sprint interval training was more effective in increasing mitochondria than an hour of "high-intensity continuous training." And an hour of high-intensity continuous training was more effective than an hour of "low-or moderate-intensity continuous endurance training," which is traditionally associated with Zone 2 work.
But that's not the end of the story. Higher training frequencies "were associated with larger increases in mitochondrial content." In other words, the reason why Zone 2 training is so important is not because there is anything magical about Zone 2. Endurance athletes benefit from Zone 2 work because it is the kind of training that can be done many times per week.
This finding shows that isolating an exact Zone 2 heart rate range is unnecessary. Nor is it a problem if you train slightly above or below your Zone 2 heart rate. The key is consistently getting in a high volume of aerobic work at an intensity that doesn't limit you the next day.
Hybrid athlete of the week: Brooklyn Nichols
Name: Brooklyn Nichols
Age: 24
Hometown: Elmira, NY
Why did you start hybrid racing? I started hybrid training when the gym I was working for became a DEKA affiliate. Once I ran my first DEKA Strong, I was hooked.
Favorite race to date? DEKA Fit Ultra. This race taught me things about myself I didn’t know. I’d always considered myself more of a power athlete, so I never imagined I’d thrive in a 25k race. But it turns out I have a knack for endurance racing, too.
Do you have a race goal? I’m aiming to go after the DEKA Fit Ruck World Record in December at the DEKA World Championships. The time to beat is 38:18!
Favorite station? RAM Burpees—they hurt in the best way.
Least favorite station? The Assault Bike. Don’t be fooled by the smile; it’s just me trying to convince myself I’m having a good time.
Things you wish you knew when you started racing? I wish I’d understood sooner how important it is to appreciate both the highs and lows of the sport. In the past, I put so much pressure on myself to reach goals that I lost sight of how lucky I am just to compete. Win or lose, PR or not, I’m grateful my body can do the crazy things I ask of it.