Jim Rowley knows uphill climbs—and which battles are worth fighting.

He’s been in the fitness industry for over 30 years, and has spent over a decade at the helm of gym chain Crunch Fitness, which operates over 400 locations. But that’s not where he learned his leadership chops. Rowley doesn’t have a college degree; at 18, he entered the U.S. Marines, where he served for eight years, including on a combat tour during the Persian Gulf War.

His time in service has informed his key values: commitment, tirelessness, perfectionism, and discipline. When he’s not visiting gyms around the country—and quizzing members in the steam room on what can be improved—he’s snow skiing, taking a midday work break for a Pilates class with his wife, or downing a protein shake.

Rowley, 57, maintains that the trappings of modern work—work-life balance, life hacks, corner-cutting—are illusions. He works on nights and weekends, and he tracks the granular details because he insists that the rewards of hard work don’t come to those who aren’t serious. Rowley took Fortune through his bold beginnings, his career trajectory, and how he ended up working for Madonna.

This transcript has been condensed and lightly edited for clarity. 

Can you tell us a bit about your early life?

I'm a sixth-generation Californian from the Napa Valley. My parents were young hippies. I’m an identical twin born to a 17-year-old mom and a 19-year-old dad. My mom walked into her high school graduation pregnant with twins, and my dad was a young U.S. Marine at the time, during the Vietnam era.

I grew up in a really military-focused family. Both my grandfathers were retired military men, so there was a lot of emphasis on serving your country. I joined the Marine Corps when I was 17, and had to wait till I turned 18 to go to boot camp. I then spent the next eight years as a U.S. Marine.

You spent eight years in the Marines before becoming a gym executive? What was that transition like?

It was impossibly difficult. I had to beg for my job, because I had no skill sets. I didn't have the sales background, I hadn't performed those tasks, so I had to call in a favor to my brother who was working for the same company. Luckily, he got me an interview, and I was able to persuade the vice president, who I was interviewing with, that I was worthy of an opportunity.

As fortune would have it, that person ended up reporting to me about six years later, and then was summarily terminated. Maybe I held a little bit of a grudge because he made me work so hard for the job. But all kidding aside, I started at the very bottom. I was called a rookie sales counselor and had a rotary phone and a Whitepages phone book, and I had to call people to come down to the gym.

You spent 16 years in leadership positions at 24 Hour Fitness. How did your time there lead you to Crunch?

I don't know that there's ever any preparation for becoming a chief executive officer. But along the way, you find different skill sets, learn different attributes, and become your own kind of leader. I was fortunate to recognize early that it’s not about me—it’s about the teams I was building. I really focused a lot of effort, energy, and time into building my team so that we had a shared mission and purpose. As I did that, my teams really promoted me, to be honest, and I was then able to promote them along the way.

Like I said, I started at the bottom. Then I became an assistant manager, then general manager, then district manager. They just kept throwing more responsibility at me. I find that you only get promoted to your highest level of incompetence, because every time, it's kind of a new challenge, so you have to redefine yourself a little bit.

But if your system is working, and you’re hiring and developing the right people, it generally becomes a habit, rather than an acquisition of a new skill set. I just performed the same thing over and over again. I kept a deep library of my training materials, and started to form a culture of training and a culture of belief. And then I tried to unify people through shared vision, mission, and purpose.

To be honest with you, most of those skill sets I learned in the Marine Corps. It's kind of the same philosophy: You take a bunch of 18-year-old young men and women—mostly men, when I was in—and you teach them to be killers. And then in peacetime, you do a lot of training and a lot of repetition.

In wartime, you put all that training to practice. Imagine having to unify a group of 100 people, all from different backgrounds and different areas of the United States. You have to unify them in one mission, which is to conquer the enemy. It's some of the best training in the world, because you're really working with them physically and mentally, and you have a shared sense that we're here to really help each other. If you can take some of those things and transfer that into business, it works.

You joined Crunch in 2009, at the peak of the financial crisis, and you led it through the pandemic. How would you characterize those experiences?

I partnered with [New York-based alternative investment firm] Angelo Gordon in 2009 to buy Crunch out of bankruptcy. It was a relatively quick assimilation, to be honest with you, because I was running 400 health clubs at my last job with 24 Hour Fitness. So the thought of running 36 Crunches seemed relatively easy. That was probably hubris, because once we dug into the system, we identified a lack of marketing, a lack of sales and operations, and a lack of personnel. But I'd always admired Crunch because at the time, most of the industry was very similar. I call it vanilla in nature—everybody was doing the same thing. Same equipment, same pricing, just different geographies.

Crunch was irreverent, fun, sassy, New York. They had more swag with 36 clubs than we had with 410 at 24 Hour Fitness. I'd always admired that; that was a big inspiration for me. But once we dug in, we found a lack of systems, ideas and vision. But there was this good root. So we started with that, lost money for the first couple years, and then started applying a lot of the same things that I talked about earlier: shared mission, shared purpose, shared vision, and operational excellence.

We franchised in 2010, and I’m happy to report we're a multi-billion-dollar company now. We have just over 460 locations open right now, but we sold 1,500 franchises. So we have about 1,100 more under contract. When I joined, we only had 36; we actually closed eight during the bankruptcy, so we had 28. And now we sit at 460-plus gyms around the world.

During COVID, we closed a couple gyms, because they were coming to the end of their leases, or the landlords were incredibly difficult in terms of negotiating with us. If we couldn't generate money, we closed. But the interesting thing about Crunch during COVID, is that we grew our club count and we grew our member base. We're currently just north of 2.6 million members, and our goal by the end of 2024 is to have 3 million members.

In the current era of opt-in cult-like fitness classes, like Barry’s and SoulCycle, alongside revelations in the weight loss industry with things like Ozempic, what role do membership gyms like Crunch play?

There is an intersection with Ozempic because what we know about this drug is that it's highly effective, but there are some side effects. One of the known side effects is muscle wasting. So you're trying to lose weight, which is great, and we try to meet people where they are in their fitness journey—whether it's through weight loss, or they've got a big event, they're getting married, they're going to a class reunion, and they want to get stronger. I say strong is the new skinny.

With Ozempic, you drop a lot of muscle. Skinny fat is not optimal. So we encourage people using Wegovy, Mounjaro, Ozempic, or any GLP-1 to join a Crunch, let us help you build that muscle, and maintain the muscle while you're dropping the weight.

As for where Crunch fits in the fitness market, we saw a lot of contraction during COVID, and we started opening boutique areas inside the gym. We've got a product called sweat shed, which is high-intensity interval training within Crunch. We have HIIT zones. We're doing a lot of the same classes you can get at a boutique, which allows you then to have the benefit of relaxing and recovering in saunas, plus cardio, plus strength training all under one roof. It’s the best of all options.

How do you prioritize fitness as a corporate executive?

Physical fitness is incredibly important for everybody, but especially for CEOs. I believe that the buck does stop at some place in an organization where there's a final decision maker. Whether you're dealing with finances, legal, taxes, employee issues, public matters, whatever—there's stress associated with that. And the best way to alleviate that stress is through exercise.

Personally, I still weight train. I think that's what gives me the best way to just exert as much force as possible and get rid of some anger. But I also do pilates twice a week, because I'm an aging athlete, and that’s really changed my life. Pilates is on a massive comeback; it's probably our number-one class at Crunch right now. It's critically important.

Eight of the 10 leading causes of death in America can be prevented through exercise and nutrition. As you get to my age, you start thinking more about prevention. I would encourage everybody to do more of that early, instead of having to catch up later. We know that stress leads to heart disease, cancer, stroke, and we reduce stress through exercise, so I'm a massive promoter of that.

Do you work out in Crunch gyms?

I work out in Crunch gyms when I'm on the road, absolutely. I visited two gyms today—our Financial District gym and our Tribeca gym. Not only do I go to my gyms, but quite often I'll shower in my gyms. I'll sit in the sauna and talk to members to get the scoop on what's happening. And then at the end, I’ll say, for full transparency. I'm the CEO, one of the owners of the gym. And they say, Oh my God, let me tell you more. I get all the local gossip from the gym.

What advice do you give to busy working people who struggle to fit gym time?

Let's break it down. You generally sleep eight hours, right? So we've got 16 left. You work generally eight hours. So how many do we have left? Another eight to relax, recover, eat, pick up our kids, read, watch TV—get in 45 minutes for an exercise. This idea that you don't have time, I just don't subscribe to. I think you need to make time for your workout. I think you'll find out, eventually, that it’s the best time that you've given back to yourself. I practice this idea that it takes 21 days to make or break a habit. So just commit to the first 21 workouts and once you've done that, it'll be part of your regular routine.

If you had to put a fine point on it, what would you say is your secret to success?

There is no secret to success. It's hard work. It's determination. It's a significant amount of courage. It's a level of understanding—being self-aware, self-reliant, getting into a flow state where you really understand where your skills and strengths transfer to the business. And then trying to build team members around where you've got liabilities. So reinforcing your strengths with others that might bring other other things to the table.

I can imagine that every billionaire you guys have interviewed for Fortune Magazine will tell you there’s no secret. It's sleepless nights, it's long days, it's a lot of airplane trips, it's staying in crappy hotels. It's all those things, which, on the outside looking in, they seem super sexy. They're not. They're a grind. And the grind is critically important. You have to accept it. You have to have grit, you have to have determination. When everybody else is looking for an answer to something, you've got to be the calmest person in the room, you've got to be a study. You've got to read, you've got to prepare. It takes a lot of effort, and it doesn't come easy. And I've never met anybody who’s created something unimaginably successful that wasn’t due to hard work and perseverance, and a lot of plotting and planning and trial and error.

I think failure is a big part of success as well. You've got to really learn. I've opened gyms all over the world—Crunch is not my only gym. 24 Hour Fitness was not mine. I created a gym called UFC Gym. I created a company called Hard Candy fitness with Madonna. I've owned yoga companies. Not everything worked. I've learned through failure, how to not repeat things. I think this is the other thing about success: You've got to get really good at repetition. When you find something that works, you've got to repeat that process over and over again. Some people might call it repetitive or mundane, but that's where the real skill comes from.

What are your thoughts about the male-dominated gym space?

For a long time, the gym bros took over the weight room. But nearly half of Crunch members are women. We appeal to that kind of mindset. We are the original no-judgments gym; we don’t cater to gym bros. We appeal to people who embrace differences and want to work out with like-minded people. There's a lot of community in our gyms.

But here's the interesting fact. Five years ago, we were opening a gym with two Olympic weightlifting platforms. Now we're opening gyms with 10. The majority of people using Olympic weightlifting platforms are women; they're dominating that space. Many women’s images of what their physical body should look like have changed, so they're working out a lot of strength. Women want to be strong. Again, I'm not speaking for everybody, but the ideal has changed. Strong is the new skinny.

When I walk into my gyms, it feels like the girls are pushing the boys around, to be honest with you. And we hope that nobody walks into our gyms intimidated. In my opinion, fitness is medicine, and we all need a little medicine. So go in there, relieve stress, decompress, work on your physical strength, work on your physical image. I think if everybody worked out more, we'd be in a much happier place.

The downside of the United States right now is that 60% of our population is overweight or obese. How do you lead anything in the free world if you're overweight or obese? We've got to really work on that. It starts with a healthy diet, nutrition, and movement. So we encourage a lot of movement.

Do you think Crunch is male-dominated?

I think Crunch is a place for everybody. We've got members that are 16 years old, we've got members that are 80 years old. We've got everybody. We embrace all types of people.

About 55% of our members are male and 45% are female. And that female share is actually growing. I'd say by the end of this year, we'll probably be up to 48% female.

The best thing about female members is they bring their friends. Gym dudes work out by themselves, or with one other person. We really encourage women to come in because they come in in twos, threes and fours. They take a class together, they do HIIT training together, they take over the Olympic weightlifting platform. And we love that. We're here for it.

The Department of Veteran Affairs reports that on average, 22 veterans take their lives every day. How do you believe that encouraging positive physical health could help veterans struggling with PTSD from their time in service?

I love this question. I really appreciate you asking it because I continue to suffer from PTSD myself. One of the biggest problems is that transition is incredibly difficult. Somebody told me early in my transition that you're never going to leave the Marine Corps and become a civilian. You're going to leave the Marine Corps and become a veteran.

That changed my mindset. After eight years of how the military does things—very rigid, it's very regimented, it's very demanding—it creates a level of intensity, and that intensity doesn't always translate into the civilian world. It's too intense.

Unfortunately, a lot of our veterans come back, and they find that alcohol, nicotine, and drugs become the outlet. Obviously, we know that's the worst path. I wish more veterans would find fitness as their outlet. But I also understand that, like they've been running and training and doing all these things—they want to get away from that. It's hard. But that difficulty, that's where the value is found.

I don't know that the military does an amazing job transitioning people out. They do an amazing job transitioning you in, because they have an ideal image of what they want you to be, but they don't take the same time to transition you out into the civilian world. One of the pledges that I've made to myself is: When I retire, I’ll spend more time helping transitioning veterans and giving them a sense of belief.

I've got a high school education and eight years in the military, and I became the CEO of a multibillion-dollar company. I’ve launched several brands. It's not unique to me—the skill sets you develop are not found in the private sector. They're really valuable. You just have to find a way to transition those into purpose and mission and focus within a private sector job.

Say you're not a former Marine, you're just a normal person looking to join a gym for the first time. What's the best workout out there for a beginner?

In my opinion, the best workout is a mix. It's generally a 10- to 15-minute warm up at a comfortable pace that creates some warmth, gets the heart rate going, and creates a little bit of sweat on the forehead.

Then, transition to a circuit training workout where you do a little bit of everything. You might do shoulders, chest, biceps, triceps, quads, hamstrings, or calves. A full-body workout, in the beginning, is the best thing you can do. And then complement at the end with some recovery, whether it be stretching or using some of the recovery devices we have.

But to be honest with you, the best way to start your workout journey is to hire a personal trainer. Hire somebody who spent four years in college, getting a degree to specialize in this field. They’ve spent thousands of hours with clients working on nutrition, supplementation, and exercise. They can work with anybody; they're generally fun. They're generally very good-looking. And you can show up to the gym, turn everything off, they'll do everything to put you through it. And before you know it, the 50 minutes have gone by. You're drained, you're sweating, you wonder why you're paying for it, and you feel the best you've ever felt. The only bad workouts are the ones you don't do.

Strength or cardio? 

Strength, 100% of the time. I'm protein powder every single day of my life.

Elliptical or treadmill? 

Treadmill.

Running or walking?

Walking, 100%. I ran for eight years in the military, and I vowed that I would only run if chased after that.

But I have a mountain bike and I live in the mountains. I'm more of an adrenaline guy. Motorcycles, surfing, skiing, bombing down mountains, pushing the edge of things.

Dumbbells or kettlebells?

Dumbbells all day, every day.

What’s your daily routine on a typical workday?

I generally wake up at 6:30 in the morning. And I take time to be somewhat reflective for the first minute or so. I'm not a bound-out-of-bed type of guy. I pull my old weary body over the side of the bed. And I try to reflect a little bit on either the day ahead, or just be somewhat grateful for the opportunity.

It's not lost on me that I get to lead this organization. I don't have to lead this organization, I get to. Because my partners, my team, my investors, trust me with that. It's not lost on me, I take a lot of responsibility for that, so I want to show some gratitude in the morning. And again, I'm not lighting candles and burning crystals or whatever. I don't want to be all hippie dippie about this. But I think it's important to reflect. I'm a hard-charging person, but I also know that I need to pause and reflect. Otherwise, it becomes all-encompassing.

Then I’ll turn on Fox Business. I'm an investor, so I like to see how the markets are doing, to see if anything burned down overnight. I always have one cup of coffee in the morning. I didn't start drinking coffee until I was in my 40s, so coffee is relatively new for me, and I've learned to really enjoy it.

After I catch up on the news, I'm on email by 7am. Because I live on the West Coast, and my home office is on the east coast, it's already 10 o'clock to them. Usually I've got quite a few emails to catch up on. The first email I'll open up is how we did yesterday. I get data on how the gyms are performing, and I can do that by owned properties, by franchisee, by region. We've got more stats than baseball. And I've got a KPI dashboard that shows me the top 20 things that I'm interested in.

Usually by 9am, I'm in meetings the rest of the day. I Zoom a lot. So from nine to noon to 12:30, it's usually resume after resume after resume. At 12:30 on Mondays, I change into my T-shirt and my shorts and I head to pilates, which is a five-minute drive. It's also the greatest blessing in the world, because I get to do pilates with my wife. and I didn't get to do that while we were raising our three children. In the middle of the day, it gives me great joy to take a pilates class with my wife. That's something I value: The chance to slow down.

Then I'll come back and I'll shower. And then I'll eat protein, generally a protein shake, some chicken, tuna salad, whatever it might be. I don't eat a lot of breakfast in the morning anymore. Then, at 2:15 is when my assistant starts booking again. So from 2:15 til, depending on the day, it could be 5:30 or 6:00. I'll continue on and then I'll take a break, usually to go for a walk. We live right by Lake Tahoe, so I get joy from going down to the lake after having sat in an office all day. It's good to get outside and breathe some fresh air.

And then we eat dinner somewhere around 7 p.m., and then I'm back on email from, usually, 8 p.m. till 9:15. Then I'm in bed, watching some sports or the news.

Do you work from home? 

I do work from home. I have an office in New York City, so I come here every six weeks for a week. But I work from home the rest of the time, or I get out to my gyms. Some days I hate working from home, because it feels quite repetitive, like: Now I'm on a Zoom call, now I'm on a phone call. I'm at my best when I'm at my gym.

Do you follow any particular diet?

I follow a modified low-carb diet. I wouldn't say it's keto, but I feel like I do better with less carbohydrates. But I also know that when you're training, you need carbs. But I am a protein-aholic. I weigh 230 pounds, so I try to get 200-plus grams of protein a day. And sometimes I'm just shoving eggs down at the end of the day.

Do you ever take a cheat day? 

Hell yeah, I cheat. I love cheat days because it looks like a cheeseburger, and I love cheeseburgers. I'm not so hardwired that I don't appreciate a piece of New York pizza once in a while. I'm not a massive sweets person, that's not a big deal for me. If I'm gonna cheat, it's gonna be a smashburger or cheeseburger. That's joyous for me.

Do you work on the weekends?

I absolutely work on the weekends. Yes.

What's your opinion on work-life balance?

I don't think there's such a thing as work-life balance. I think work life-balance is for somebody who's not fully committed. It depends on what your "why" is. If your "why" is really purposeful, and goal-oriented, you're gonna find an imbalance in pursuit of that. Nobody ever had a perfect balance in pursuit of something great. You're either all in, or you're somewhat in, or you're not in at all.

I challenge my teams all the time because I hear a lot of "Well, I want to get promoted." And "I want a bigger gym" and "I want to be a district manager," and "I want a new house" and "I want a new car." I say, those things are amazing, those are your wants. But what are you willing to do to get them? And when you ask somebody what they're willing to sacrifice, you hear crickets. People haven't thought it through.

We live in this instant-gratification society. But what really works to become a successful leader is hard work, determination, planning, constant self-realization, self-awareness, challenging yourself. Those are the difficult things.

I live by this motto: No one is coming. It's up to you. If you want something, don't look for it to come from, like, oh, what books do you read? And what did you study in school? No. It's right here. It's your DNA. It's not your résumé. Do you have the drive and the determination and the discipline to get what you want? And if you're willing to make those sacrifices, there's going to be an imbalance in your life. If you're seeking harmony, I don't know. I have never found it.

This story was originally featured on Fortune.com