Confidence Isn’t a Personality Trait, It’s a Muscle
- Brainz Magazine
- Oct 7
- 3 min read
Updated: Oct 8
Written by Lisa Sheerin, ICF PCC Executive Coach | Transforming Confidence, Communication & Leadership
Lisa works as an executive public speaking coach, actor, and fitness enthusiast. She is passionate about helping people overcome imposter syndrome and find their authentic voice to unlock career success in business and beyond. She is the founder of Speak Proud.

Confidence isn’t born, it’s built. Lisa Sheerin PCC reveals how practice, repetition, and voice training create authentic self-belief.

Confidence isn’t something you’re born with
When clients first come to me, they often say a version of the same thing.
“I just want to feel more confident.”
They talk about confidence as though it’s something missing, a quality other people were born with. Confidence isn’t a personality trait. It’s not genetic luck or natural charisma. It’s a muscle, and like any muscle, it strengthens through deliberate use.
We mistake confidence for charisma
We’re taught to believe confidence looks loud, the smooth presenter, the effortless communicator, the person who always knows what to say. In truth, most “naturally confident” people have simply built familiarity through repetition.
As a voice actor, I spend hours tightening diction, shaping tone, and practising until control becomes instinct.
As a coach, I teach executives the same principle, your voice, posture, and presence are all trainable behaviours, not personality traits. “Confidence doesn’t arrive. It’s built, one rep, one call, one meeting at a time.”
Muscle memory lives in your voice
When your voice trembles or your throat tightens before you speak, it’s not failure. It’s your body doing what it has practised, holding tension and anticipating judgment. The antidote isn’t more positive thinking. It’s retraining the system through physical anchors:
Ground your feet before you speak.
Exhale fully before you answer a tough question.
Pause mid-sentence instead of rushing to fill the silence.
Each of these is a micro-rehearsal that tells your body, I’m safe to take up space. Do them daily, and confidence becomes muscle memory, not a mindset trick.
Repetition rewires fear
Neuroscience backs this up, the brain can’t tell the difference between performance and rehearsal. Every time you repeat a behaviour with safety and awareness, you reprogram your nervous system to prefer that state. That’s why my coaching mantra is simple:
“We’re not chasing confidence, we’re training it.”
Through repetition, the unfamiliar becomes natural, and fear loses its edge.
Confidence doesn’t look the same on everyone
For some, it’s quiet composure in a meeting. For others, it’s courage to voice an opinion that once felt too risky. For most, it’s the relief of sounding like themselves, without apology or an inauthentic performance.
When I voice a commercial, my goal isn’t perfection, it's authenticity. When I coach leaders, it’s the same. Because confidence isn’t about sounding impressive, it’s about sounding true.
Final thought
The next time you tell yourself you’re not confident, remember, you’re not missing something, you just haven’t trained it yet. Your voice, your body, your presence, they’re waiting for consistent, compassionate repetition.
Warm them up. Use them daily. Watch your confidence grow.
Read more from Lisa Sheerin
Lisa Sheerin, ICF PCC Executive Coach | Transforming Confidence, Communication & Leadership
Lisa works as an executive public speaking coach, actor, and group fitness instructor with over 20 years of experience. A graduate of a three-year drama school program in London, she began her career in theatre and film, where she faced and overcame imposter syndrome. Today, she empowers others to embrace their authenticity and transform self-doubt into confidence, combining her acting expertise, fitness training, and passion for personal growth. Her mission is to guide others toward a life where they can speak and live proudly.