Most fitness apps are built by tech founders who hire trainers later. 12REPS is different—it was built with a qualified personal trainer from day one.
That trainer is Will Duru, and his 10+ years of hands-on experience training women in London gyms shapes every workout, every progression, every programme in the app.
This isn’t algorithm-generated training created by software engineers who’ve never coached a client. This is evidence-based programming designed by someone who’s spent thousands of hours actually training women, understanding exactly what works, what doesn’t, and what women need to achieve their strength goals.
I’m Godswill, founder of 12REPS. When I decided to create a strength training app specifically for women, I knew I needed more than just a good idea, I needed the right expert to ensure every workout delivered results.
This article explains who Will Duru is, his qualifications and experience, his training philosophy, why his expertise matters for your results, and how his knowledge is embedded into every 12REPS programme.
Who Is Will Duru?
Will Duru is a BSc-qualified personal trainer with over 10 years of experience training clients in London gyms and studios.
Qualifications
BSc (Bachelor of Science): Will holds a BSc degree, providing him with a scientific foundation in human physiology, biomechanics, and exercise science that informs his evidence-based training approach.
Level 3 Personal Trainer Certification: According to UK fitness industry standards, the Level 3 Personal Training qualification is the required certification to work as an independent personal trainer in the UK. This CIMSPA-accredited qualification covers:
- Advanced anatomy and physiology
- Exercise programme design
- Nutrition for exercise
- Client consultations and assessments
- Health and safety
- Business skills for fitness professionals
Will’s Level 3 certification demonstrates he has met the professional standards set by CIMSPA (Chartered Institute for the Management of Sport and Physical Activity), the UK’s professional body regulating personal trainers.
Experience: 10+ Years Training Women in London
Will has spent over a decade working with women in London’s competitive fitness market—training clients in gyms, studios, and private settings.
Why this matters: Ten years of consistent client work means Will has:
- Trained hundreds of different women with varying goals, body types, fitness levels, and challenges
- Observed what actually produces results long-term (not just what looks good on paper)
- Developed an understanding of common obstacles women face and how to overcome them
- Refined his coaching ability through thousands of training sessions
The difference: A trainer with 10+ years experience has seen patterns that take years to emerge—what causes plateaus, what prevents injuries, what creates sustainable progress, what keeps women motivated beyond the initial 12 weeks.
This depth of experience can’t be replaced by reading research papers or completing courses. It comes from being in the gym, year after year, adjusting programmes based on real client feedback and real results.
Training Philosophy: Evidence-Based Progressive Overload
Will’s approach is built on three core principles:
1. Progressive overload is non-negotiable
Muscles grow stronger when they’re progressively challenged. Will’s programmes systematically increase weight, reps, or sets over time—ensuring continuous adaptation and strength gains.
Not random workouts: Every session builds on the previous one. This week’s squat weight is based on last week’s performance. Next month’s programme is structured around this month’s progress.
2. Compound movements first
Will prioritises multi-joint exercises (squats, deadlifts, hip thrusts, presses, rows) that work multiple muscle groups simultaneously.
Why: Compound movements:
- Build the most strength in the shortest time
- Increase bone density more effectively than isolation exercises
- Burn more calories per session
- Improve functional strength for daily activities
- Allow heavier loading (critical for bone and muscle development)
3. Evidence-based, not trend-based
Will’s programmes are informed by peer-reviewed research on strength training adaptations, not social media fitness trends.
Example principles backed by research:
- Training each muscle group 2-3x weekly produces better results than once weekly (frequency)
- 10-20 sets per muscle group weekly is optimal for most women (volume)
- Progressive overload must occur for continued adaptation (progression)
- Rest and recovery are essential for muscle growth (periodisation)
Why Will's Expertise Matters for Your Results
Reason 1: Proper Form Prevents Injuries
One of the biggest barriers preventing women from strength training long-term is injury. Poor form—especially on compound lifts—can cause joint pain, muscle strains, or worse.
Will’s contribution: Every exercise in 12REPS includes video demonstrations filmed by Will, showing:
- Correct starting position
- Proper movement execution
- Common mistakes to avoid
- Alternative positions if you have limitations
Impact: You learn proper form from the beginning, reducing injury risk and ensuring exercises actually target the intended muscles.
According to the National Careers Service guide on personal trainers, one of the key responsibilities of qualified PTs is teaching proper technique to prevent injury—exactly what Will’s video library provides.
Reason 2: Programme Design for Women’s Goals
Will has specialised in training women for over a decade. This means he understands:
Body composition goals: Women typically want to build muscle in specific areas (glutes, legs, upper body) whilst reducing fat—requiring careful programme balance.
Strength progression patterns: Women progress differently than men due to hormonal differences. Will’s programmes account for realistic progression rates.
Common obstacles: Menstrual cycle impacts on training, balancing strength training with cardio, fitting workouts into busy schedules with work and family.
Psychological barriers: Fear of “getting bulky,” uncertainty about weights to use, intimidation in gym environments.
Result: 12REPS programmes are designed specifically for women’s physiology, goals, and challenges—not generic programmes adapted from men’s training.
Reason 3: Balancing Science With Practicality
Academic research provides the foundation, but real-world application requires practical experience.
Example: Training frequency
Research says: Training each muscle group 2-3x weekly optimises muscle growth.
Practical reality: Most women can’t (or don’t want to) train 5-6 days weekly. Life, work, family, other commitments exist.
Will’s solution: 12REPS offers programmes ranging from 2 to 4 days weekly—all effective because they maximise quality per session rather than requiring massive volume.
Example: Exercise selection
Research says: Barbell back squats are highly effective for leg development.
Practical reality: Not everyone has access to a barbell. Some have knee issues. Some train at home.
Will’s solution: 12REPS provides alternatives—goblet squats, Bulgarian split squats, dumbbell lunges—that produce similar results with different equipment or work around limitations.
Reason 4: Understanding Long-Term Adherence
The best programme in the world is useless if you stop after 3 weeks.
Will’s insight from 10+ years: Sustainability matters more than perfection. A “good” programme you follow for 12 months produces better results than a “perfect” programme you abandon after 6 weeks.
How this shapes 12REPS:
Realistic session lengths: 30-45 minutes, not 90-minute marathon sessions that exhaust you and eat your entire schedule.
Flexible frequency: Choose 2, 3, or 4 days weekly based on your actual availability, not what’s theoretically optimal.
Equipment options: Gym programmes (full equipment), home programmes (dumbbells only), or hybrid (some gym, some home).
Built-in deload weeks: Every 5-8 weeks, volume reduces to allow recovery and prevent burnout.
Result: Programmes you can sustain for years, not just weeks—which is what actually produces transformation.
How Will's Knowledge Is Embedded in 12REPS
1,500+ Exercise Video Demonstrations
Will has filmed over 1,500 exercise demonstrations for 12REPS, covering:
- Every major compound lift (squats, deadlifts, hip thrusts, presses, rows)
- Isolation exercises (bicep curls, tricep extensions, lateral raises)
- Alternatives for different equipment (barbell, dumbbell, cable, bodyweight)
- Modifications for limitations or injuries
Each video shows:
- Starting position
- Full range of motion
- Key form cues
- What to avoid
Why this matters: You’re learning from a trainer with 10+ years experience teaching these movements to hundreds of clients—he knows exactly what cues help women understand proper form.
Structured Progressive Programmes
Every 12REPS programme is built on Will’s understanding of progressive overload:
Week 1-2: Learn movements, establish baseline strength Week 3-4: First weight increases as form solidifies Week 5-6:Continued progression, building confidence Week 7-8: Heavier weights, approaching first plateau Week 9: Deload week (reduced volume for recovery) Week 10-12: New progressive phase with adjusted exercises
This isn’t random workouts—it’s systematic programming based on Will’s experience with how women adapt to training over time.
Exercise Substitutions and Alternatives
Will has programmed multiple options for each movement pattern:
Vertical push (shoulders):
- Barbell overhead press (gym)
- Dumbbell shoulder press (gym or home)
- Pike push-ups (bodyweight at home)
Horizontal pull (back):
- Barbell bent-over rows (gym)
- Dumbbell rows (gym or home)
- Inverted rows (using TRX or sturdy table at home)
Hip hinge (glutes/hamstrings):
- Barbell deadlifts (gym)
- Dumbbell Romanian deadlifts (gym or home)
- Single-leg RDLs (lighter weight, can do at home)
Why this matters: Whatever your equipment situation, you can follow effective programming without compromise.
Warm-Up and Mobility Protocols
Will has designed warm-up sequences for each workout type:
Lower body days:
- Dynamic leg swings
- Hip circles
- Bodyweight squats
- Glute activation exercises
Upper body days:
- Arm circles
- Scapular movements
- Band pull-aparts
- Light pressing movements
Why most people skip warm-ups: They don’t know what to do or think it’s unnecessary.
Will’s approach: Specific, purposeful warm-ups (5-7 minutes) that prepare the exact muscles and movement patterns you’re about to use—reducing injury risk and improving performance.
Tutorial Content and Coaching Tips
Beyond exercise videos, Will provides:
Technique tutorials: Detailed breakdowns of complex movements (squat mechanics, hip hinge pattern, bracing for deadlifts)
Progression advice: When to increase weight, when to add sets, when to progress to harder variations
Common mistakes: What to watch for (knees caving in squats, lower back rounding in deadlifts, elbows flaring in bench press)
Troubleshooting: What to do if you feel pain, if an exercise doesn’t feel right, if you’re plateauing
This coaching knowledge—accumulated over 10+ years—is embedded throughout the app, providing guidance even without face-to-face training.
Real Client Testimonials About Will's Training
Lucy Gornall (Level 3 Personal Trainer, Health & Fitness Journalist)
Lucy has trained with Will for years and written about his training approach in Fit & Well magazine:
“My personal trainer Will Duru says the exercises below are ideal for targeting the whole upper body. ‘Make sure that the last two reps of each set are a challenge. If they’re too easy, up the weight, but make sure your form is still on point. Think about the muscles working as you move—that mind-muscle connection will help you really achieve more from each exercise!'”
Why this matters: Even a qualified PT with her own Level 3 certification chooses to train with Will—demonstrating his expertise is recognised by other fitness professionals.
The 12REPS Difference: Expert-Led, Not Algorithm-Generated
Most fitness apps take one of two approaches:
Approach 1: Generic algorithms Programme builder creates workouts based on user inputs, but lacks personalised expertise or coaching knowledge.
Approach 2: Influencer-designed Social media trainer creates programmes, but often lacks formal qualifications or long-term client experience.
12REPS approach: Expert-designed programmes Every workout is designed by Will—a BSc-qualified, Level 3 certified trainer with 10+ years of hands-on experience training women.
What this means for you:
✅ Exercises selected by someone who’s taught them hundreds of times
✅ Progression structured based on real client adaptations, not theoretical models
✅ Form cues refined through years of correcting common mistakes
✅ Programme sustainability built on understanding what women can actually maintain long-term
The Bottom Line
12REPS isn’t just another fitness app with AI-generated workouts. It’s a platform built on Will Duru’s decade of expertise in training women in strength.
Will’s qualifications:
✅ BSc degree (scientific foundation)
✅ Level 3 Personal Trainer (UK industry standard certification)
✅ 10+ years training women in London
His expertise is embedded in 12REPS:
✅ 1,500+ exercise video demonstrations
✅ Structured progressive programmes (2-4 days weekly options)
✅ Evidence-based training principles (progressive overload, appropriate volume/frequency)
✅ Practical alternatives for different equipment and situations
✅ Warm-up protocols and mobility work
✅ Tutorial content and coaching tips
Why this matters: When you follow a 12REPS programme, you’re not getting random workouts—you’re getting training designed by someone who’s spent 10+ years in the gym, working with hundreds of women, understanding precisely what creates results.
You’re getting his knowledge on proper form, his experience with progression patterns, his understanding of women’s goals and obstacles, and his ability to balance science with practicality.
The result: Programmes that actually work because they’re designed by someone who’s proven they work—with real clients, over real years, producing fundamental transformations.
Try 12REPS free for 7 days. Experience the difference between generic fitness app workouts and expert-designed progressive strength training.
Will spent 10+ years perfecting his training approach. Now you can benefit from that expertise without paying £85 per session for in-person training.
Your strength journey deserves expert guidance—not algorithmic guesswork.
