Meet our Trainers

Get to know our highly experienced and professional training team below!

Berkeley Y Trainer Bios

Daniel Sperber

Hi, I'm Daniel!

Certifications: 
NASM Personal Trainer

Bio:
For as long as I can remember, I have challenged myself in a variety of physical activities. Whether it is running a little faster, cycling a steeper climb, or lifting a heavier weight, I’ve always enjoyed both the physical and mental aspects of exercise. In college, I was an NCAA athlete and competed in the sport of gymnastics for the University of California Berkeley. About 5 years ago, I joined the Berkeley YMCAwhen my niece challenged me to take up barbell weights. I was inspired to become a certified personal trainer after being approached by fellow members for help with their form and technique. I found assisting others to achieve their fitness goals to be incredibly fulfilling. I like to keep things simple and enjoyable. Each client should have a progressive, fulfilling, and sustainable program created for their needs. The journey should be as enjoyable as achieving the goal. I aim to program workouts with functional fitness in mind. I would like members to be physically fit for whatever they enjoy in life, whether it’s a particular sport, activity, or living life. I prefer to keep things simple with the use of free weights and bodyweight movements.

Likes and interests?
In the gym, I enjoy training the Olympic lifts and various gymnastics movements. Outside the gym, I love to cycle and run in the Berkeley hills. Woodworking and my next trip to
Japan are also high on my list.

Favorite quote:
“Health is the greatest gift, contentment the greatest wealth, faithfulness the best relationship.” 
-Buddha

Interested in working with Daniel, contact Lulu Zapata, lzapata@ymcaeastbay.org to learn more.

Wyatt Berreman

Hi, I'm Wyatt!

Certifications:
NASM Personal Trainer
 
Bio:

I was born and raised in Berkeley, and have been a part of the Berkeley Y since I was a kid learning how to swim here. Growing up I loved playing sports and currently play ultimate frisbee with the professional team Oakland Spiders. I got interested in personal training through helping friends and other members with exercises and form. After hearing how helpful my advice was, I developed a passion to help people reach their fitness goals and got certified through NASM during the lockdown and started training people on my own time while working other part time jobs. Post lockdown I decided to focus more on a career in fitness and thought the Y where I first started helping people would be the perfect place and started working here in January 2024.

Training style:
When training clients, I like to keep things simple, straightforward, and enjoyable so working out is something you look forward to and want to do. I like to train using a combination of free weights, body weight, and band exercises focusing on everyday movements to make life a little bit easier. I won’t make you do an exercise if you truly don’t want to do it, but will always emphasize why it’s a good exercise and why I want you to do it.

Likes and interests: 
Outside of playing and coaching ultimate, I’m passionate about calisthenic exercises and can find me in the gym floor trying my best to perform them. Outside of exercise I love movies, spending time with friends and family, and spending time with my dog. Feel free to say hi if you see me in the weight room.

Interested in working with Wyatt, contact Lulu Zapata, lzapata@ymcaeastbay.org to learn more. 

Luisa “Lulu” Zapata

Hi, I'm Lulu!

Certifications: 
NASM Personal Trainer, CF-L1

Bio:

II was never a sporty child growing up, I got into sports when I moved to the US in my early 20s, when I (almost accidentally) got into the water polo team at Laney college. After my experience there and with the pandemic, I wanted to continue with an athletic activity, and that’s how I found CrossFit and functional fitness. This really helped me get through a tough time, and empowered me, by making me feel strong and able to do and learn new skills. I’ve learned that it is never too late to find an interested in sports and overall wellbeing. I want to help people, especially women, the Latine/Spanish-speaking community and the queer community find that passion for their wellbeing, Selfcare and health. I want people to enjoy their workouts, so I will always work with you to find your preferences, but know that I’ll try to challenge you by introducing new and varied movements where we can work on technique, stabilization and endurance.

Likes and interests: Cats and any cute animals, food, craft beer and CrossFiT

Interested in training together?
Reach out to me directly at lzapata@ymcaeastbay.org

Osiel Quintero

Hi, I'm Osiel!

Certifications: 
NASM Personal Trainer

Bio:

I grew up in Oakland and have lived in the East Bay my entire life. As an adolescent, most of my time was spent participating in organized sports, such as basketball and baseball. My athletic endeavors eventually transitioned into resistance training during the pandemic while I was an undergrad Kinesiology student at Cal State East Bay. My background in Kinesiology made the transition relatively smooth as I could apply the knowledge I was currently learning in anatomy, physiology, biomechanics, etc., to aid me in my training journey and overall lifestyle. I got involved in personal training through an internship where I built exercise programs and trained faculty members from CSUEB. 

Through my internship experience, I found it fulfilling to positively impact the lives of individuals by helping them strive toward their fitness goals and improve their overall health. I also learned how vital it is to build relationships with the people you work with, whether clients or peers. I believe clients deserve an individualized exercise program that caters to their needs and yields positive results. I strive to create programs for clients that are enjoyable but also challenging through the use of free weights, machines, cables, etc 

Likes and interests:
I currently enjoy working on cars, reading, gaming, playing sports, and spending time with my friends, family, and cats.

Favorite quote:
"One day, in retrospect, the years of struggle will strike you as the most beautiful.” —Sigmund Freud

Interested in working with Osiel, contact Lulu Zapata, lzapata@ymcaeastbay.org to learn more.

Estefanita “Stefi” Stofleth

Hi, I'm Stefi!

Certifications: 
NASM CPT

Bio:

I come from a family of volleyball players and have played the sport all my life. Both of my parents were coaches which inspired me to transition from playing to coaching as well. Through coaching, I found a passion for learning more about athletics as well as teaching others. I have seen the positive impact that playing a sport and exercising can have on people of all ages not only in terms of health, but also for building lifelong skills like communication and teamwork, finding a community, and simply for the enjoyment of getting active.

What is your training philosophy?
I want you to be able to care about your health in a way that doesn’t feel like a chore; I want to push you to learn and explore all types of fitness to see what will work best for you to keep you coming back to the gym. My hope is to build confidence so that you can feel capable of taking charge of your health and fitness.

Do you specialize in any particular type of training?
I have extensive volleyball knowledge but I also have familiarity with broader related concepts such as plyometrics, agility, and other power development techniques. I tend to focus on free weight exercises when training as well.

Likes and interests:
I enjoy a fun little treat like a coffee or a good dessert. I like to watch a volleyball match with my family, especially if it’s a team they play on or coach. When I can, I spend time reading and I also try to do some crafting from time to time.

Interested in working with Osiel, contact Lulu Zapata, lzapata@ymcaeastbay.org to learn more.

Daniel
headshot of personal trainer wyatt
Personal Trainer Lulu Zapata
Osiel Quintero
Estefanita "Stefi" Stofleth

Oakland Y Trainer Bios

Aaron Thomas

I’m a passionate personal trainer who thrives on helping others solve problems and achieve their fitness goals. My fitness journey began in high school when I started lifting for my football team, and I quickly fell in love with building myself and sharing what I learned with others. 

I am accredited through the National Academy of Sports Medicine (NASM) and hold certifications in Personal Training, Group Fitness Instruction, and Neuromuscular Stretching. I specialize in areas such as corrective exercise, strength and endurance, weight loss, flexibility and stretching, foam rolling, balance and posture, bodybuilding, plyometrics, and SAQ training. My sociable and supportive approach creates a welcoming environment where clients feel empowered to push their limits and succeed. I’m excited about the opportunity to begin training with you and help you attain your goals! 

Brittany Rusch

I am a Coast Guard veteran and mom who is passionate about movement and inspiring others to want to move! I grew up with a love for playing sports, exploring the great outdoors, and being in service to others.

I hold an M.S. in Sports and Health Sciences along with Personal Trainer (ACE), Health Coach (ACE) and Corrective Exercise Specialist (TBMM) certifications. I offer a wide range of program design options that are tailored for your specific needs and abilities. This may include stability exercises, agility work, stretches for flexibility, strength training, cardio-conditioning, and corrective exercises to address imbalances. The mission of the Y makes me excited to be a part of this team. I am here to help you reach your goals! 

Jeff Rapson

Physical fitness has always been a fundamental part of my life; I played several sports as a kid, primarily basketball, baseball and soccer. When I was about ten years old, I got a bench, barbell and weights (the old kind, filled with sand) and started weightlifting at that time. It was the 1970s, and so much less was known about physical fitness than today, but I did realize that I felt happier and stronger after lifting weights. I never forgot that and that has never changed. When the first running boom occurred around this time, I started to run and later got passionate about that, leading to me running the San Francisco Marathon in 1985.  I have consistently been a fitness fanatic and can almost assure myself a pretty good day if I do something active, whether lifting weights, running, bicycling, jumping rope, hiking or yoga.  

I retired from teaching high school (Berkeley and Oakland) after a thirty-year career and became certified as a personal trainer from ACE fitness in January 2023 because I wanted to share my passion and knowledge of physical fitness with others. About a year later I also became certified through ACE in Senior Fitness because I really enjoy working with that population, but I enjoy working with all ages, fitness levels, etc. Many clients may either be trying to get back into shape, are recovering from an injury or are just intimidated by the vast array of workout options available. I enjoy helping them navigate through some of these perceived complexities. Helping others is extremely rewarding, and I am grateful that I work at the Oakland YMCA. 

Jo Scully

I have always had an interest in health, wellness and fitness and enjoyed playing volleyball and basketball earlier in life.  As a career, I became a certified massage therapist specializing in working with people who have rotator cuff issues and low back issues too.  A few years ago, I lived in the Caribbean and worked as a massage therapist at a beach resort.  It was then that I took an interest in Olympic weightlifting and powerlifting as a hobby.  I started interning at that gym and now hold a Level 2 CF coach certification, in addition to being a personal trainer.  Currently, I am educating myself in Sports Nutrition with online courses, and I am excited to be working here at the YMCA.

Joe Brigandi

I have a lifetime of fitness and movement including soccer, track and field, and boxing. I became a trainer to help others with health and fitness. My hobbies include paddle sports, healthy cooking, and dance.

My certifications include NESTA Certified Personal Trainer, NASM Senior Fitness Specialist, NASM Weight Loss Specialist, Red Cross Lifeguard, Silver Sneakers (Foundations, Circuit, Fall Prevention Education Series, Stability, Fundamentals of Teaching Group Fitness, Nutrition for Optimal Aging, Stress Management Education Series) 

headshot of trainer aaron thomas
headshot of brittany rusch
headshot of jeff rapson
headshot of jo scully
headshot joe brigandi