Owner Kinsey Diment opened Fit After 40 in November 2025 because she’d spent over a decade watching women in perimenopause and beyond not getting the attention they deserve.
Kinsey knew exactly what women new to strength training, navigating chronic pain, past surgeries, and years of being told fitness wasn’t for them needed; and she knew the gyms she’d worked at didn’t have it.
So she built it.
Fit After 40 is a small-group strength training studio built specifically for women 40 and up who are ready to start lifting the right way: with proper foundations, real attention to form, and a coach who understands their bodies. Kinsey is already watching women shock themselves lifting far heavier than they ever imagined, moving with less pain, and showing up for themselves in ways they never have before.
We sat down with Kinsey to talk about what it took to make the leap, what she loves most about this work, and the advice she’d give any gym owner who feels like they’re planting seeds with nothing to show for it yet.
How long have you been a gym owner?
I’ve been in the fitness world for over a decade, but Fit After 40 was opened in November of 2025! So we’re coming up on 8 months soon!
Why did you decide to open a gym?
I work with a lot of beginners and with women in perimenopause & beyond who are brand new to strength training and often struggle with various injuries, chronic pain, and surgeries. I’m deeply passionate about helping women learn how to start strength training the RIGHT way: building foundations, bulletproofing against injury, not wasting time.
I am a big believer that small-groups allow folks to get the one-on-one attention to form and programming they need to be successful—especially in a population who generally comes in with chronic pain. Before I opened Fit After 40, I was working at a gym where a lot of women in that age sought help, but we lacked what they needed for true success. I realized then that there was a major gap in our market, and I felt an obligation to fill it!
What was your job prior to being a gym owner?
I was managing and coaching at a local gym. I loved the community there, but as I mentioned above I felt a pull to create Fit After 40! I have been in gyms for the last 14 years. I started at a front desk at a gym in Los Angeles called Easton Gym Co, and it was there I fell in love with being in gyms.
The people, the community, the positivity, the focus on health. I was instantly hooked. I quickly moved up to management and realized I wanted to be IN THE STUDIO. I started training around 2014 and I have worn pretty much every fitness hat there is: gym manager, fitness director, personal trainer, group fitness instructor, gym owner!
How has your life changed since you became a gym owner?
My cup is so full. It is amazing how I can still work the same amount of hours I did working in a corporate gym, but not feel completely burnt out at the end of the week. I feel a sense of responsibility to my clients, employees, and future clients to continue growing and learning. To create a space that is safe, inclusive, welcoming, and fun.
One common thread from all the studios I have worked at is that the owner of the gym sets the tone for the rest of the studio. If the owner is involved, comes into the gym, stands at the desk welcoming members, greeting employees by name, caring about numbers, doing the workout…and is TRULY involved, the ecosystem follows suit.
When an owner is hands off, removed, out of the loop, just in it for the money—this is when I’ve watched all the jenga pieces underneath start to tumble. People deserve a healthy, autonomous life as they age. Fitness is a big part of that. It is my responsibility to share that passion, and to get others passionate and excited about it.
What do you love about being a gym owner?
I can’t imagine a gym owner who wouldn’t say this, but THE PEOPLE.
I feel like the luckiest lady in the world being surrounded day in and day out by women who are actively shredding through diet culture narratives and getting stronger FOR THEIR HEALTH. I work with a lot of women who “don’t like working out.” Watching them show up consistently, feeling stronger, moving with less pain in their day, building confidence, and start to even enjoy themselves? That feeling is unbeatable.
I also love that there is always more to learn. Whether it is business, sharpening my tools as a trainer, becoming a better leader, working on my own personal mindset, marketing…ABL, baby, always be learning. And as a gym owner…that is going to be the case forever.
What’s your biggest pet peeve as a gym owner?
Not being able to do it all at once—especially in the beginning there are about 8 billion things you CAN do at any given time, but you only have so many hours in the day…and both my husband and dog insist I clock out at 6.
This is a big reason I love Kilo! There is so much time I have wasted making a subpar website, following up with every lead without a system, don’t get me started on trying to ChatGPT what the heck SEO is. They’ve cleared up so much time for me to focus on things I’m good at!
What’s your most memorable moment as a gym owner/coach?
I suppose one of my favorite things about coaching is that it’s so hard to pick just one moment! A lot of my favorites include women who always described themselves as “not fit” or “exercise just isn’t for me” falling in love with working out. Feeling stronger in their body. Shocking themselves by not only lifting heavier than 5-pound weights, but lifting WAY heavier than five-pound weights. It’s such an empowering feeling and a tangible change in their confidence and how they show up even outside the gym!
My favorite of all moments, though, would probably have to be training my mom. She has experienced a life of chronic pain—low back, double knee replacement—and truly didn’t think she would be able to get stronger or lift weights. Now, at 68, for the first time ever she is not only squatting & deadlifting without pain, she’s excited about PRing! Getting to witness her being so proud of herself (as she should be), watching her CELEBRATE herself, watching her bravely SHOW UP for herself, after decades of putting others first? My heart has never been fuller!
What’s something people would be surprised to know about you?
It always surprises people when I tell them I’m actually a little shy and am an introvert—especially if they meet me in the gym 😂.
What’s your favourite part of being a Kilo gym?
I don’t feel like I have to do this alone. There are so many plates in the air, and knowing that I can reach out and find help immediately is such a relief. Plus, everyone on the Kilo team is so wonderful—I look forward to learning from them!
Also, did I mention? I literally don’t get SEO.
What advice would you give someone opening a gym for the first time? Or somebody going through a slump?
I have 3!
1. Your members are your gym! Nurture and celebrate them. It goes a lot further to keep a client for 12 months than to get 12 new short-term members.
2. Treat your gym like a garden. Keep planting the seeds and tending to them, but don’t rush the process. When we do the right things—marketing, outreach, going into our community, client retention practices, team meetings—the payoff is inevitable…but it usually isn’t on our timeline. One of the hardest mindset pieces for me was feeling like I was doing all the things for no reason. When in truth, things were happening on their own timeline, it was just a month or two or six after I had hoped.
3. Don’t be afraid to invest in help! There is too much to do alone, and too many people who can help you do it better. Wasted time is wasted money. And let’s be real—a lot of the time we just straight up waste money throwing things at a wall. It’s hard as a new business owner to invest before you are profitable, but an investment in help is an investment in your gym, and at least for me? It’s always leveled me and my studio up.
