“Until a man is about 25 years old, he believes, under the right circumstances, he could be the baddest motherfvcker alive.”

That’s a quote from Neil Stephenson in his (excellent) book, Snow Crash. And, as I’m not yet 25, I still believe it for myself. 

Not in the literal sense of course, but in the sense that I think every young person has the potential within themselves to grow into somebody who’s not only dominant in their sport…

But also has an unspoken confidence in social circles…

And makes a positive impact on those around them.

My name is David Rosales. I’m a writer and former personal trainer. I’m the co-owner of Roman Fitness Systems, the head editor of SCAPH (the official website of the NHL strength coaches), and winner of best hair in my high school class. 

David Rosales Fitness

My work has been featured in some of the top health and fitness publications in the world, from Muscle & Strength to the Personal Trainer Development Center. Just for fun, here’s a graphic of most of the places I’ve been featured. Oh, I also left out my publication in Esferas, a Spanish Poetry magazine (I’m a man of many talents, yes). 

Since I Turned 18, I’ve dedicated my life to personal development…

Uncovering, learning, and applying the best methods for training athletes… 

but also the role athletics plays in helping athletes become the best version of themselves.

From working with NHL strength coaches and NCAA DI athletes, to spending countless hours reading and researching the latest training info, to using myself as a guinea to test a myriad of protocols, supplements, and training theories…

I’ve put in a lot of effort to really figure out what works, what’s a waste of time, and how to most effectively teach what works to athletes at nearly all levels

Of course, I’m still learning (and lucky to be surrounded by some of the top writers, coaches, and thinkers in the world). But in the last few years, I’ve helped dozens and dozens of athletes (probably hundreds, I’m not really giving myself enough credit) reach the next level in their athletic career…

from middle schoolers who didn’t even know what a squat was when I met them, to NCAA athletes about to earn their first professional contract.


For me, the reason I love coaching and working with athletes isn’t just about how you can score more goals this season, or finally make the AAA or Junior A team, or even about getting those shredded six pack abs you’ve always wanted…

(Although we will focus on any of these if that’s your burning goal)

It’s about taking the lessons you’ll be learning from enhancing your training and sports performance…

And using that to make you a better person.

A better leader in your locker room.

A better friend.

A more confident human who people look to and admire in a crowded room.

A happier person who’s excited and confident about their path in life.

Look, I know this sounds a bit hyperbolic (yes, my vocabulary is also exceptional)… But I say this because I know the massive impact the right mentor can have on somebody’s life.

At 22, I’ve already accomplished a lot, from training to writing (not to mention enrolling in a prestigious university, which makes my mother very happy). I have my life weirdly together, and I’m excited for the crazy journey life is going to take me on.

But trust me, I didn’t always have it even remotely put together.

When I was 16 years old, I was an ordinary Junior B hockey player from Vermont. All I wanted was to become the best hockey player I could possibly be, and I took the steps everybody tells you will get you there.

I showed up to the rink early. I stayed late. I gave every game, practice, and drill my full attention and intensity.

When I was away from the rink, I lived in the gym. I wasn’t going to give anybody any reason to think they worked harder than me. Maybe this sounds a bit like you.

After my second season of junior B, I had been working my butt off for the previous two seasons, and I felt like there was nothing more I could have done to prepare myself to make the jump to junior A. I was even a captain of the team.

We had our “end of season meetings,” which is as stressful as it sounds. I walked into the Junior A coach’s office, and hoped for good news.

I’ll spare myself the details of that interaction, because less than five minutes later, I exited the rink embarrassed, on the verge of tears. Overcome with resentment and frustration, all I wanted to do was cry, scream, and get out of there.

I’d put everything into hockey.

David Rosales Hockey
Circa 2016

My heart. My soul. I’d even skipped school dances to get up early and stick to my training program. I had totally bought into the belief that if you work hard, you get success.

The problem is, it’s not that simple. Have you ever heard the expression “going nowhere fast?” Well, that’s where I was going. Nowhere. It didn’t matter how hard I worked.

In fact, the fundamental component I lacked was a mentor figure who I could trust to guide me, to make sure that where I was going wasn’t nowhere, but actually somewhere I wanted to go.

I didn’t have the person in my life who I could really go to, who’d been through the grind of competitive athletics like I had, who could guide me through my struggles, point me in the right direction, give me guidance when I didn’t know how to ask for it… so that I wasn’t just working hard and expecting magical results…

No one who could help me channel my effort in the most effective means possible.

I even had a coach who I (still to this day) have a great relationship with, and loving parents who supported me regardless.

But as any you probably understand, there’s something different about those relationships, and a mentor/big brother figure who’s been in very similar shoes.

Later that year, the right book fell into my hands at the right time (books can sometimes fill the role of mentor). It was called The Art of Learning by Josh Waitzkin.

Becoming an expert in learning, according to Josh Waitzkin — Ivan Ivankovic

In that book, Waitzkin wrote about how when training any skill, it’s not how often or how vigorously you do something, it’s about mastering the basic element of that skill, and then building outwards.

Immediately, I thought about how this applied to hockey. I was trying to work too hard, to go 1000 mph everywhere in my life. When what I really needed was to slow down, work on my skating, my stickhandling, my form in the gym, mastering and continue to practice the fundamentals before getting sidetracked with anything else.

In other words, hard work is completely useless if you’re not working smart.

And if you’re already working hard, more hard work is not the solution.

Truth be told, the potent lesson was a little late to turn me into a professional hockey player (although I’m very proud of what I accomplished later at the Junior A level).

But it came at the perfect time to help me grow as a young personal trainer, learn a new language, become a published writer, and most importantly, to teach the lessons I’ve learned to the athletes I worked with in all contexts, from the weight room and beyond.

That was the first time a book, and a mentor in the form of a book, fundamentally changed who I was as a person and how I approached the world. 

It wouldn’t be the last. 

Working smart has since become one of my key training (and life) philosophies.

It’s a foundation of my training programs and of my recommendations to the people I train in nearly all areas of their life. 

More specifically though, when we narrow down on the problems that plague young athletes…

You don’t just need to work harder. If that were the solution, any truly motivated athlete would have done that and solved the problem by now. 

Instead, they need timely guidance in the form of somebody who’s been in your shoes and understands your situation.. Advice that can help you avoid negative rabbit holes and always stay on course for what’s best to move you toward your goals.

Yes, you need a well-designed training program that takes your needs into account…

But that’s really not enough, because you can find good programs on the internet.

You also need…

The coaching to implement the program,

The teaching to understand the program,

The mentorship to support you to become the best version of yourself. 

Online Personal Development Mentorship

In my career, I’ve trained people in just about every setting. 1-on-1, small group, large group, youth teams, junior teams, college teams.

Nothing to me has been as rewarding as the coaching I’ve done in a 1-on-1 virtual setting. In 2018 when I first made the shift to add online clients, I called it online coaching. But I’ve realized that mentorship is really the right word for it.

A teacher is someone who can explain something to you. You go to them for a specific lesson. A coach is someone who helps you with an entire domain. You go to them for a specific topic. But a mentor…

A mentor you don’t know what it is you need to learn, but you just have a feeling that whatever it is you need to learn, you want to learn it from them.

You might not know why habits like meditation, journaling, cultivating courage, reading, listening to podcasts, writing, and more might be just the skill or habit you need to talk your life to the next level, but it might.

As your (potential) mentor, I’m committed to helping you discover and develop whatever skills you need, with guidance personalized to you.

My online training is not so much training, as it is gaining somebody who’s on your side supporting you 24/7 with everything in life. Yes, the backbone of that will be writing a kickass, customized workout program set for your situation, including:

  • What your goals are
  • Your strength and weaknesses in your movement and in your sports
  • Your training experience
  • Your schedule
  • What equipment you have available
  • Okay you get the point I’m obviously making you a completely custom program

However, the much bigger components include the personal support that comes with it. Every week we’ll Facetime (or Zoom but tbh Facetime is just easier) to discuss everything that has come up in the past week regarding your training and life.

We’ll talk about the workouts, discuss improvements we can make to your program together. At first, we’ll likely spend more time dialing in your training habits and technique. 

But depending on where you’re at in your training, this is also the time where we talk about everything from your nutrition and sleep habits (and how to improve them with custom suggestions for you)…

to the book you’re reading and why you’re struggling in Algebra II…

to what you should say to your coach who’s benching you,

to what texts you should send to your crush (yes, this is included in the comprehensive service).

And of course, any other questions that come up for you I am all ears to support you in finding the best solution. 

Truth be told, though, we can only get so much done in a weekly Facetime. So, you’ll have my cell phone number. And you can text me whenever.

In fact, I generally enjoy dropping knowledge bombs and good advice via text, so I encourage you to text me whenever.

And like you, I’m also part of Gen Z and therefore I’m addicted to my phone, so you’ll get timely responses. 

All told, here’s what you’re getting with coaching program

  • Custom training programming designed to focus on your strengths, weaknesses, equipment availability, and schedule.
  • Weekly Facetime calls to talk check in about your workouts, nutrition, life, or whatever.
  • Unlimited texting to ask as many questions as you have or to just send me Tik Tok (bonus points if you send Spongebob Tik Toks)
  • One bail out from jail (and I won’t tell your parents either)
  • Advice on how to approach a tough conversation with your coach
  • Help studying for the SATs
  • Help writing messages to your crush or your Tinder match (personal I prefer Hinge but whatevs)
  • Unsolicited advice on the best TV shows and books
  • I’m running out of things to say but you get the point; I’ll help you with anything and I plan on us developing a close relationship. In fact, I’ve done all of these and much more.


I expect you to be as excited for this as I am.

I do not work with everyone who comes my way. I do not want to have to babysit you.

If accountability is your main sticking point, and just showing up is a challenge, that’s something I’m more than happy to work through.

But there’s a big difference between struggling to form good habits, and simply not putting the effort in.

If you don’t want to do the latter, then I’m going to have a hard time going to bat for you week in and week out.

But, if you’ve read this far, I’m guessing you’re already motivated to improve, and want to take your development to the next level. 

Here’s a bit more about the lessons I hope to impart along our journey.

My Training (and Learning) Key Philosophies

Question the Assumptions

I can’t give you a surefire formula for success and happiness, but I can give you one for failure: Doing things to please other people, and following a path because it seems like what you should do.

Now there’s nothing wrong with the well-worn path. It’s well-worn for a reason. It’s fine. It’s comfortable, it takes relatively minimal effort and doesn’t require you to ask deep questions of yourself. On the main path, you can create a comfortable, safe, (probably a bit boring) life. If you were blessed with a privileged upbringing, you’ll be able to coast if you really want to.

That’s not what I chose. Nearly every time I made the conscious choice to question why we do what we do, it led to forging a new path that nobody else had taken before, to a path in life that was uniquely mine.

I will not push my opinions and perceptions of the world on you (okay, maybe I will a little bit), but my goal for you will be to look at training, sports, relationships, and everything in your life through a lens that pushes your thinking. And when you push your thought process, ultimately, you push your life to new levels also. 

Success Lay in the Ruthless Execution of the Basics.” Do The Basics Savagely Well

I’ve talked to just about all of the top strength and conditioning coaches in the hockey world, and I’ll tell you something: most of what they’re doing isn’t rocket science (just don’t get Mike Potenza started on blood testing). From the beginner levels to the best of the best, a lot of training comes down to variations of the basics.

You have to squat, deadlift, push, pull, and sprint. You have to find a way to get that work done during the season, in the offseason, and while you’re playing three different sports in three different seasons. And you need to get that work in a way where you’re constantly progressing a little bit.

I remember when I was working with a top 20 division 1 hockey team, Umass Lowell. They were split squatting (that’s one leg) as much as 535 lbs, and every sophomore and up lifted more than 400 lbs. Yes, this sounds as ridiculous as it looked. 

How? They trained consistently. Year round. For years. The results of sustained, consistent training led them to become the type of physical specimens most people would only attribute to good genetics. I’m not offering magic bullets here.

Sure, I know how to program with the best of ‘em. My access to NHL strength coaches gives me cutting-edge info on the best training methods, but, I’ll be honest, that’s not really going to make the biggest difference for you.

What’s important is that you master the basics and create systems so that you’re always getting your work in, 50 weeks out of the year.

It’s All About Relationships

Of course, I want you to become a badass, specimen of an athlete. But one of the most important lessons I’ve learned is that success and fulfillment in life is more often about the quality of your relationships and your ability to connect with people.

Think back to your happiest moments in life. The ones that replay in your head. How many of those were special because of the people you were with at the time? Probably most of them.

I attribute my success professionally to my ability to build relationships, my likeability. I’ve dealt with a verbally abusive coach, with crazy teammates. I’ve made a study of human nature a principle component of my college education. In the context of sport, dealing with the people that can either help or hurt our success isn’t always easy.

Sometimes you have to deal with asshole coaches, annoying teachers, or problematic teammates. These situations often govern our success in sports, and learning how to deal with them is a huge piece of the puzzle to sports success and your happiness. (After all, how much fun is it when you get to play sports with your best friends?)

These social dynamics are often challenging to navigate, but they’re often really what’s keeping you back from growing as an athlete and person.

Further, learning how to build relationships will help you connect with those people you look up to, who you want to learn from. Imagine what a deeper connection with your coach or an older player you look up to would mean? Focusing on people skills is inextricably linked to your success as an athlete. On top of that, these interpersonal skills you learn will translate into making you a better person, and prepare you for life well beyond sports.

Here’s What Some of My Clients Say About What we do


Sam Solod

Sam forgot to take before photos. Here’s after 6 months and then 12 months

Throughout my time (going on two years) working with David, I have got much more out of it than just getting into better shape for hockey. I now have a mentor and friend that I do not only talk to become more explosive in our next offseason phase, but for much more. In addition to helping me go from a high school player to a junior player on the track for college hockey, he’s made me a better professional and a clearer thinker. I wouldn’t have my job, both literally in terms of who he connected me with and in terms of the skills I have, if it weren’t for my deep work with David. I would recommend anyone looking to get into a better lifestyle in general to David. He will do everything that he can to make you a better person all around.

Aidan Haggerty – Canadian University lacrosse player

After (well, still in progress)

I’ve worked with David since I was 16 years and had just gotten cut from my high school team. Over the years, and more recently in his online mentorship, he’s been integral in my development into a college athlete. From workouts, to sleep routines, David has helped me to become entirely more fit and healthy as a person. I’m more confident in myself and a lot less likely to second guess myself in my daily life. Whereas before I hid in my shell, I stride around with a confidence I previously thought I’d never have. Above all, working with David is fun. Our calls often go over the allotted slot, as we talk about life, politics, Spongebob memes, and more. 

Markuss Komuls – NCAA Division 1 hockey player

“Rosie” as we always called him in juniors, was one of the smartest teammates I’d ever played with. When I was struggling early in my college hockey career, I knew I needed to make a change. So, I reached out to David to support me with my training. At the time I was recovering from a herniated disc injury and he adjusted the workout plan to my needs. Now, I’m the strongest, most explosive, and fastest I have ever been. He has also helped me develop a nutrition, supplement, and sleep plan to support my performance on and off the ice. David is professional, reliable and always learning more about his craft. I would recommend his coaching to any athlete/hockey player.

(When some of my teammates see me doing his workouts, they like to jump in because of how much we all get out of them.)

What Coaches I Work With Say About My Skillz

Mike Potenza – San Jose Sharks Director of Strength and Conditioning

CSCS Spotlight | Mike Potenza of the San Jose Sharks

David is a young professional who has gained a wealth of experience and knowledge within the field of performance training In a short time. His commitment to learning and passion for training allow him to design programs that are age appropriate, meet the goals of his athletes and provide a safe training environment. There is no doubt in my mind that any athlete would benefit greatly by working with David.

Also, Moms Love Me.

Becky Wigglesworth

David has been such a great influence on our son Aidan.  We appreciate his thorough knowledge of physiology and current approaches to fitness and training for sports. He has had a significant impact on Aidan’s athletic performance. More importantly, though, David has forged an important relationship with Aidan and has been an excellent role model. Aidan really looks forward to his weekly chats with David about his training but also his sports, school, and anything else that comes up. This connection has been invaluable.  I am also delighted that David is imparting the knowledge and skills that Aidan will need to train and pursue his fitness goals independently.

I Only Go Deep With People

I really don’t like surface level relationships. I like to either be in a passive, teacher-type role for people (like I am writing articles), or I want you to be a part of my life.

I understand this creates a bit of a flaw in my business model: I can’t work with many people because of how much energy I put into each client. In fact, I limit my roster to five at any given time. And because I want to go deep and ensure my clients’ success and growth, I have to charge an appropriate amount. My online fitness mentorship costs $300/month. 


(by “Apply” I mean send me an Instagram DM until I set up a fancy application form.)

Now, this is not an insubstantial amount of money, even though for my qualifications and experience I know trainers who charge $500 or even $1000 per month and provide much less support and personalization. And they’re also just way less cool than me, let’s be honest. 

However, I’m charging less because I know it’s a cost that’s realistic for most families, and I don’t want to pigeonhole myself into only working with rich, snotty, AAA-kids-who-only-made-it- because-of-their-dad’s-connections kind of people, and I’d rather charge less to work with people who give me energy instead of take it away.

If this sounds like a substantial investment, I want you to put the cost of athletics into context. If you’re a junior hockey player, you’re probably paying $8000 per season. For a six month season, that comes to over $1,300 per month, more than four times the cost of deep one-on-one mentorship. What would an extra fraction of that cost mean to you if you could ensure you’re developing to your potential… While improving in a myriad of other areas?

I have had a client who jumped from the Eastern Hockey League, a pay-to-play league, to a league where he got to play for free. While I of course do not take credit of his development (although I do take credit for his split squats), investing in his improvement allowed him to save money in the long-term, and I’d go as far to say his willingness to prioritize his development in all areas is what got him to the next level (he now plays NCAA Division I hockey). 

For more context, consider what you likely already do spend $300/month on. You probably break a stick that costs that every freaking month. 

Finally, add up all the money you spend monthly on items like video games, tv subscriptions, chipotle, and other expenses. You’d probably be surprised this adds to the cost you could be spending to take your performance to the level you dream about.

I also want you to understand that I’m only able to do this at all because, even though this coaching takes up a good portion of my time, when it’s with the right people, I absolutely love it. But as much as I enjoy it, I also can’t give away my time, and I have a shoebox apartment on Manhattan’s Lower East Side (a grungy but cool neighborhood) to pay for.



If you’re thinking, “David, I’m all in on this, have you seen this economy,” then please talk to me. Or have your parents talk to me. I do offer partial scholarships, especially for BIPOC individuals and those coming from underprivileged communities.

In just a short time, you and I are going to be working on everything you need to become the best athlete and person you can be.

Con ganas de empezar,

Your mentor,




What if I’m not an athlete and just want to get in shape?

If your main goal is to learn how to exercise, to build confidence, to become a better version of you, then it doesn’t matter where you are on your fitness journey. In fact, if you’re starting out, it’s probably a much better choice to hire a coach and actually learn the fundamentals so you can succeed on your own rather than try to do it on your own. In a few short months, you could build the foundation necessary for you to later succeed on your own.

Do you work with women?

Yes. I have coached dozens of women from varying ages, from middle schoolers to busy moms. I tend to work with young men because the competitive world I grew up in (junior hockey) is male-dominated (unfortunately). 

Is there a minimum time you work with someone?

Like I said, the fulfillment for me with this mentorship is that I get to know someone deeply and help them with underlying struggles in their life, not just give them a workout program and abandon them. With that said, I typically require a 3-month commitment, although we can talk about extenuating circumstances.