Meet the team

We’re a diverse team with different stories and strengths, united by a shared passion for making our community healthier and happier. Gravity is a place where everyone belongs, supported by people who show up each day with experience, empathy, and heart.

Introducing the squad that turns workouts into good times and goals into reality.

Kieran rundle

Owner, Personal Trainer & Group Fitness Coach

The man with the wild idea that started it all! Over a decade ago, Kieran founded Gravity Fitness with a simple goal: to create a space that inspires people to move, connect, and grow stronger every day. With more than 20 years in the fitness industry and qualifications including an Associate Diploma of Applied Science in Management, Certificate III & IV in Fitness, and Certificate IV in Training & Assessment, he brings both passion and experience to everything we do, from business direction to hands-on coaching.

Around here, Kieran’s known as “Bob the Builder.” Whether he’s repairing equipment, redesigning spaces, or finding creative ways to make the gym better, he’s always got a tool in hand and a new idea in mind. You’ll also find him coaching group fitness sessions at our sister studio, Unity Hybrid Training, and working with members one-on-one as a personal trainer. He’s your go-to guy for behind-the-scenes solutions or a great chat about training philosophy (or the Cowboys’ latest game).

Fun fact: before building Gravity, Kieran was literally flying high! He was a skydiving instructor with the highest rating, represented Australia in the sport, and completed over 7,000 skydives. He’s played nearly every sport under the sun and still carries that same adventurous, go-for-it spirit into every day at the gym.

Mafalda Birne

Manager, Exercise Physiologist and Personal Trainer

Originally from Portugal, Mafalda first came to Australia while solo travelling and quickly fell in love with the country’s lifestyle and people. After exploring for over two years, she decided to continue building on her established fitness career from Europe, where she worked as an exercise physiologist, personal trainer, gym manager, and later as a strategy consultant.

Mafalda holds a Bachelor’s degree in Physical Education and Sports, specialising in Exercise and Wellbeing, with a major in Personal Training and Sports Management. She also holds a postgraduate qualification in Sports Management and Marketing, as well as a Master of Science in Management with a focus on Strategy and International Business. She is the brains behind our operation as Fitness Centre Manager and the go-to for detailed systems, big-picture thinking, and strategic suggestions.

Fun fact: Mafalda has a different last name to one of her siblings because her dad mixed up the surnames when registering them. In Portugal, it’s common to have multiple last names, which can lead to mix-ups if you’re not careful.

TJ Tabusakia

ALL-ROUNDER

Originally from Fiji, TJ’s journey began on the footy field, first bringing him to Australia, then to the Whitsundays to play for the Brahmans. With a strong background in fitness and youth sports development, he’s all about keeping people active and motivated.

Around Gravity Fitness, TJ is our all-rounder. From greeting members at reception to keeping equipment in top shape, he’s the guy who remembers your name, your favourite workout, and probably your weekend plans too.

Fun fact: TJ is a true jack of all trades: a handwriting wizard, barber, and musician, with a touch of Irish heritage (yes, really!). Whether you need a friendly chat, a solid gym tip, or a tune to lift your mood, he’s your go-to.

Shannon Smith

PERSONAL TRAINER & SPORTS NUTRITIONIST

With more than 20 years in the fitness industry, Shannon brings a rare blend of deep expertise, practical wisdom, and the kind of dry humour that somehow makes mobility drills feel less terrifying. As an ISSN Sports Nutritionist, Personal Trainer, CHEK Practitioner Level 2, and CHEK Holistic Lifestyle Coach, he has helped clients across the globe move better, feel stronger, and finally understand how to train in a way that honours both their goals and their bodies. Shannon specialises in pain management, overcoming injuries, addressing training limitations, and improving mobility, and he’s known for helping people transform their bodies through sensible, sustainable nutrition. No fads, no guesswork, just a measurable method that keeps both coach and client accountable each week.

Before settling in the Whitsundays, Shannon spent years overseas training clients from all corners of the world, an adventure that eventually inspired him to open his own gyms in Victoria. These days, he brings that same worldly perspective and no-nonsense coaching style to every session.

Fun fact: Shannon is the 2017 World Thumb Wrestling Champion. Yes, it’s a real thing, and yes, he’ll happily defend the title if you ask.

Leanne Knox

PERSONAL TRAINER

With over 35 years of experience coaching human movement, Leanne brings a wealth of knowledge and passion to Gravity Fitness. Her journey began in gymnastics, laying the foundation for an extraordinary career that now spans to Olympic Weightlifting, Powerlifting, and Mindset Coaching. She holds a Bachelor of Education in Physical Education, is a certified Olympic Weightlifting and Powerlifting Coach, and is qualified in the Neuroscience of Coaching.

Leanne is a world record holder in both Olympic Weightlifting and Powerlifting, proof of her dedication to strength, technique, and performance. She’s especially passionate about helping people of all ages move better, from beginners to athletes, and has a special interest in coaching those over 50, supporting women through peri and menopause, and adapting training for people with disabilities. Her coaching philosophy blends strength, mindset, and joy in movement.

Fun fact: as a mum of six, Leanne knows a thing or two about patience, balance, and a good laugh. She believes training should be as fun as it is empowering, so if you’re looking to lift your game and your mood, she’s your go-to barbell and mindset guru.