St. Louis Personal Trainer & Pro Bodybuilder

BODY.
MIND.
WILL.

Transforming bodies and mindsets through mental determination and elite personal training. Led by Pro Bodybuilder William Anderson.

1:1
Private
Training
PRO
Body-
builder
4
Program
Types
STL
314-964-
7114
Private Training ★ Semi-Private ★ Group Fitness ★ Online Coaching ★ Meal Plans ★ Competition Prep ★ Body Transformation ★ WillPower Fitness Factory ★ Private Training ★ Semi-Private ★ Group Fitness ★ Online Coaching ★ Meal Plans ★ Competition Prep ★ Body Transformation ★ WillPower Fitness Factory ★
Our Mission

BUILD THE WILL.

Empowering clients to transform their body and mind by building the habits, discipline, and willpower necessary for lasting success.

Our Vision

BUILD THE COMMUNITY.

To create a community where individuals develop the confidence, discipline, and resilience needed to achieve their fitness goals and become the strongest version of themselves — physically, mentally, and personally.

Read our values & promise →
Training Programs

CHOOSE YOUR PATH

Every program is built around your goals, your schedule, and your willpower.

01
Private Training

1-on-1 sessions built entirely around you. Full attention, max accountability, and programming tailored to your exact goals and abilities.

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02
Semi-Private

2–4 clients per session. The energy of a crew with the precision of individual coaching — personalized attention in a tight-knit group.

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03
Group Sessions

High-energy group fitness for all levels. A social, motivating environment built to keep you consistent and committed to your transformation.

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04
Online Training

Access structured programming through the training app. Train on your schedule with William's full coaching system in your corner.

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William Anderson — competition pose
2nd Place Overall
WNBF Garden City Natural · Augusta, GA
William Anderson training
William Anderson with WillPower clients
Your Trainer

WILLIAM
ANDERSON

Owner · Personal Trainer · WNBF Pro Bodybuilder

The Flex Facility
Resident Trainer · St. Louis, MO

William Anderson is a WNBF Pro Bodybuilder and certified personal trainer based in St. Louis. He built Will Power Fitness Factory on one belief: every client already carries the willpower to transform — they just need the right system and someone who won't let them quit.

Whether you're chasing fat loss, serious muscle, competition prep, or just want to move and feel better — William builds the program around your life, not the other way around.

Certified Personal Trainer WNBF Pro Bodybuilder Meal Planning Competition Prep Online Coaching
Train With William →

Free Consultation

GET SESSION INFO SENT TO YOUR PHONE

Drop your number — a coach will text you pricing, availability, and next steps within 24 hours.

By submitting you agree to receive SMS from Will Power Fitness Factory. Reply STOP to opt out anytime.

Client Results & Competition Record

REAL TRANSFORMATIONS

William Anderson — competition champion
ST. LOUIS NATURAL CLASSIC
Overall Champion · WNBF Pro
"

William doesn't just train your body — he trains your mindset. Down 28 lbs and stronger than I've ever been. Best investment I've made in myself.

★★★★★
Marcus T.
Private Training Client
"

Semi-private is the sweet spot. You get the personal attention but there's energy in the room. Seven months straight — first time in my life I've been this consistent.

★★★★★
Deja M.
Semi-Private Client
The Flex Facility · St. Louis, MO · 314-964-7114

READY TO TRAIN?

Stop waiting on yourself. Book your first session with William and start the transformation.

Book Your Session →