1 in 2 Girls Will Quit Sport During Adolescence. You Can Be the Reason One of Them Doesn't.
A free sneak peek with Dr. Julia Casadio, sport physiologist and three-time Olympic team practitioner. Founder of Her Strength.
THE PROBLEM
Most coaches aren't failing their female athletes on purpose.
They're failing them because nobody ever taught them what's actually happening in a girl's body during adolescence, and how much it shapes her experience of sport.
Girls get taller before they get stronger.
They put on body fat before puberty settles.
They get their period, often unpredictably, sometimes painfully, and rarely with anyone around who knows what to say.
Meanwhile the coaching playbook stays the same one built for boys, whose puberty tends to work with sport instead of against it.
The result: by the end of adolescence, only one in three girls are still playing.
Girls drop out at roughly twice the rate of boys, and it isn't because they stopped loving sports.
It's because their experience of it stopped working for them.
Coaches have more influence over that experience than almost anyone else in a girl's life.
The problem was never a lack of care. It was a lack of knowledge, and knowledge is exactly what closes that gap.
That's exactly what Dr. Julia Casadio set out to fix with the HerStrength Coach Course.
WHAT YOU'LL LEARN
In this free sneak peek, Julia walks through:
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Why girls are leaving sport — the real drivers behind the dropout numbers, and why they have almost nothing to do with a lack of talent or love for the game
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Peak height velocity — the single biggest growth spurt of adolescence (avg. age 12, but anywhere from 10–14), what it does to coordination, balance and injury risk, and the specific coaching adjustments that protect an athlete through it
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The menstrual cycle as a barometer of health — why 66% of teen athletes say their cycle affects performance, what the evidence actually says about performance changes, and how to build the kind of trust where an athlete will actually tell you what's going on
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Low energy availability — the quiet imbalance between fueling and training load that puts developing bones at risk, and why it's more common, and more preventable, than most coaches realize
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What to say (and what never to say) — the specific comments (direct and indirect) that shape a girl's relationship with her body, and how small shifts in language change outcomes
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This isn't a lecture on female physiology. It's a practical playbook, built by a sport physiologist who has spent three Olympic cycles and her own adolescence learning exactly what's at stake.
Supported By
Instructor
Founder, HerStrength
Dr. Julia Casadio
Dr. Julia Casadio is a sport physiologist and applied researcher who spent the last three Olympic cycles with the New Zealand Olympic team, helping athletes win five medals at the Games. As a competitive cross-country skier, she developed an eating disorder after a coach told her to "lean up," an experience that pushed her out of sport, and later became the reason she founded Her Strength.
She's built a team of five specialists in sports medicine, nutrition, strength & conditioning, and adolescent psychology, so the course treats the whole athlete, not just the physical side.
Meet Her Team
Dr Tanya Keogh
Tanya has served as acting medical director for multiple sports teams and brings orthopaedic expertise to the health risks unique to young female athletes. She leads Module 3: Young Female Athlete Health Considerations.
Dr Sylvia Goedeke
A dietitian and university lecturer with a PhD in female dietary needs, Sylvia has spent years helping young female athletes fuel properly through her private practice. She leads Module 4: Nutrition Optimisation.
Shaun Paterson
Over 20 years coaching athletes from youth to Olympic level, with deep experience in female athlete development. Shaun leads Module 5: Training and Recovery Optimisation, with hands-on video demos coaches can use immediately.
Rachel McLeod
Rachel holds a Master's in adolescent brain development and served as team psychologist for the 2024 NZ Youth Olympic Team. She leads Module 6: Psychological Considerations, covering the mental side of coaching teenage girls.
AFTER THE SNEAK PEEK
If this sneak peek changes how you see the girls you coach, the full HerStrength Coach Course goes considerably deeper.
Across 6 modules and 32 lessons, Julia and her team of experts- a sports medicine doctor, a dietitian, a strength & conditioning coach, and a sports psychologist specializing in adolescent brain development, build a complete picture of what adolescent female athletes need to stay healthy, confident, and in the sport they love.
It covers puberty and its impact on training, the menstrual cycle, nutrition, training load and recovery, and the psychological side of coaching a teenage girl, then turns every topic into something you can actually use on the field, not just know in theory.
Coaches who've completed it report real, measurable shifts: higher knowledge across every core topic, more confidence adjusting training around a growth spurt or a tough training block, and far more comfort simply having the conversations that used to feel off-limits.
HerStrength Coach Course
✅ Lifetime access: yours from the moment you enroll
✅ Every future update included: as the science develops, so does the course
✅ Delivered by a team of 5 experts across sports medicine, nutrition, strength & conditioning, and psychology
✅ Self-paced: work through 6 modules and 32 lessons on your own schedule
✅ Instant access: start your first lesson within minutes of enrolling
See What Others Are Saying
Hayden Shearman
"As a male coach, these conversations can be tricky to have with our athletes, but Her Strength has given me not only the knowledge to feel more confident, but also loads of practical tips for creating a supportive environment for our young female athletes.”
Joe Rowley
"Despite having over 15 years of experience working in health and performance, I found the Her Strength course to be immensely valuable. I highly recommend this course to anyone interested in the well-being of active adolescent females."
Jade Peters
"When I signed up for this course, I had little to no knowledge about the female athlete and how puberty can affect them throughout their development. After completing this course, I feel my knowledge has grown to the point where I have more confidence in guiding female athletes to achieve their goals and discussing these subjects with them.”