October 15, 2025

Invest in 12REPS: The Strava of Strength Training | y combinator

By Will Duru, BSc (Hons) Sport and Exercise Science, Award-winning Personal Trainer with over 10 years of experience in strength training and optimising recover

12REPS: Strength Training, Social and Simple

Mission

  • Make lifting as engaging and social as Strava is for running and cycling.

The problem

  • Most lifting apps are digital notepads.

  • Some are so clunky they slow your workout.

Our solution

  • Seamless workout logging.

  • Clear progress charts that motivate.

  • A real community of lifters.

What it feels like

  • Hit PRs alongside friends worldwide.

  • Join team challenges.

  • Share wins in the app.

Why now

  • Strava has 135+ million athletes.

  • Weight training was the fastest-growing sport type among women in 2024.

  • The appetite for connected fitness is big. 12REPS meets it.

Who we are

  • Founder: Will Duru, BSc (Hons) Sport and Exercise Science.

  • Award-winning personal trainer with 10+ years coaching.

How it works

  • Data-driven programming that personalises plans instantly.

  • Simple filtering questions, not AI hype.

  • Video library with 1,500+ lifts to guide every rep.

Outcome

  • Every rep is set up for strength gains.

  • Every session feels social.

  • You lift harder, stay consistent, and see progress.

y combinator, in 12REPS: The Strava of Strength Training | $300K Seed Round 2025

Why Investors Are Excited: Market & Trends

Why 12REPS fits the moment

The market is big and growing

  • Fitness app revenue was about $10.6B in 2024. Analysts expect ~$23B by 2030. 

  • North America is nearly half the market. Around 46–47% share. 

  • People are downloading. ~858M fitness app downloads in 2023. 

Strength training is the gap

  • Runners and cyclists have Strava.

  • Lifters still do not have a single, social home at scale.

  • Momentum is clear. Women’s weight training uploads on Strava grew ~25% year-over-year. 

Capital is flowing into AI fitness

  • US digital health raised ~$6.4B in H1 2025. 

  • Nearly $4B of that went to AI-enabled companies. 

  • Investors back apps that use AI personalisation, wearable data, and simple UX. 

Community is the hook

  • Social training is surging. Run club participation on Strava up ~59% in 2024. Group sessions keep people active longer. 

  • Gen Z and millennials treat fitness like a social platform. Clubs and groups are rising fast. 

Why 12REPS wins here

  • Smart programming that adapts as you train.

  • Data into action. We turn sets and reps into clear next steps.

  • Social features that keep you consistent. Live leaderboards, team challenges, shareable sessions.

  • A clean, userfriendly app that people enjoy using every day.

Bottom line

  • Big market. Strong growth.

  • Strength training is underserved.

  • AI and community are where the money and users are going.

  • 12REPS is built for this.
Y Combinator, batch of 2025 and 2026

12REPS’s Unique Advantage

What makes 12REPS investable now

We meet the criteria savvy seed investors seek. We have:

Huge addressable market: Strength training is a massive and growing segment of the $10 billion fitness app industry. As lifestyles focus on health and muscle, more users seek guided lifting apps.

Clear differentiation: Unlike basic gym logs, 12REPS is built by trainers. We offer personalised workout plans on demand, real-time video coaching demos, and progress analytics. Current apps miss this blend of tech and personal touch. Industry analysis confirms that apps must solve specific problems better, not just be “another library” to succeed. 12REPS does just that, customising every plan to the user’s goals, equipment, and feedback.

Strong founding team: Will Duru leads 12REPS. He’s an award-winning trainer with a degree in Sports Science, a proven expert who has lived the problem. Our small team also includes seasoned developers and coaches who know how to engage gym-goers. Investors love domain experts, and that’s exactly us.

Early traction & validation: We launched in June  2025. Even in these first weeks, we’ve confirmed demand: dozens of lifters are already building routines on 12REPS, and the feedback has been enthusiastic. We’re on track to reach 1,000 active subscriptions. (In fitness apps, adoption scales fast once the product resonates.) User surveys show that lifters crave exactly what we offer; they’ve used every generic app, but none of them have stuck. 12REPS changes that narrative.

Monetisation and growth model: We offer a proven subscription model. Leading apps like Strava and MyFitnessPal show that freemium plus paid perks works. 12REPS starts at a low price point (e.g. £9.99/month, with a 7-day free trial) but builds lifelong users who pay for accountability and results. As users lock in routines and see real gains, revenue scales. Social features generate organic user growth, a viral loop that costs little to fuel.

Taken together, 12REPS sits in the sweet spot: a high-growth category, a defensible product, and an experienced team. Our competitive landscape (apps like Strong, Fitbod, Hevy) shows there’s room. None offers the full Strava-like experience for lifters. The only way 12REPS fails is if an incumbent builds exactly what we have. But incumbents are not moving this fast. Fitness startups must keep innovating or be left behind. We are innovating with AI-adapted plans, video coaching, and community.

Y Combinator, batch of 2025 and 2026

Industry Validation & Partnerships

What makes 12REPS investable now

We meet the criteria savvy seed investors look for. We have:

Huge addressable market

  • Strength training is part of a fitness app market worth about $10.6 billion in 2024, projected to reach ~$23 billion by 2030. North America is ~46–47% of that revenue. People downloaded ~858M fitness apps in 2023. 

Clear differentiation

  • Built by trainers, not just engineers.

  • Personalised plans on demand.

  • Real-time video coaching demos.

  • Progress analytics that tell you what to do next.

  • We solve a specific lifter problem instead of being “another library.”

Strong founding team

  • Led by Will Duru, award-winning trainer with Sports Science degree.

  • Backed by coaches and developers who know how to engage lifters.

Early traction and targets

  • Launched June 2025.

  • Strong early demand and enthusiastic feedback.

  • On track to reach 1,000 active subscriptions.

Monetisation and growth model

  • Low-friction subscription with free trial.

  • Price point designed for scale.

  • Social features drive organic growth and referrals.

Our retention engine (the “keep them for years” plan)

Plan-Ahead Folders

  • Users can plan weeks of training in advance.

  • Sessions save into named folders for each block or goal.

Data Vault Folders

  • All logs, PBs, videos, and trackers auto-save into folders.

  • Searchable. Exportable. Easy to revisit past cycles.

Community that matters

  • Gated, subscription-only community.

  • Live leaderboards, team challenges, coach Q&A.

  • You pay to belong, and you get clear value.

Dropbox-style storage for your gym life

  • We become the long-term home for your programs and data.

  • Store once. Access anywhere. Keep your training history for years.

  • This storage-first habit is a proven winning strategy.

Why this boosts retention

Social features and progress analytics improve engagement and adherence in health apps. We build both into the core experience.

Y Combinator, batch of 2025 and 2026

What We Offer Investors

We are raising $300,000 for a 10% equity stake in 12REPS. This valuation reflects the massive potential, our head start, and the bootstrap we’ve already achieved. There’s a $5,000 minimum investment. Funds will be deployed primarily on product development (finishing advanced features, scaling our tech infrastructure) and marketing (targeted campaigns, partnerships, and community events). We’ve been scrappy to date, but this capital will enable us to accelerate user acquisition and refine the app more quickly.

For a timely investment, consider what’s at stake: In the next 12–18 months, 12REPS can capture a large share of this niche market. With fitness app revenues growing at a rate of ~14% CAGR and social fitness trending upward, even a small market penetration could significantly multiply your stake. With your support, we can rapidly expand our team (including developers, coaches, and marketers) to meet demand. We will use agile metrics, such as user sign-ups, weekly active users, and engagement time, to ensure these round triggers real scale.

We’ve built the foundation; now we need partners to join us. As a founding investor, you’ll have direct access to our progress and the opportunity to shape our strategy. 12REPS isn’t a soulless software project; it’s a personal vision turned business. We’re real people solving a real pain point. Over a decade, Will has worked with clients who needed exactlywhat 12REPS provides. We know the community intimately, and we’re hungry to win.

Act now. The fitness tech wave is cresting, and gaps fill quickly. By investing today, you position yourself ahead of the curve. Don’t wait for competitors to latch on; join us in building the Strava of strength training from the ground floor. We welcome strategic and passionate investors who share our vision of making lifting fun, social, and effective.

For more information or to schedule a call, please contact 12REPS founder Will Duru at will@just12reps.com. Let’s discuss how we can install 12REPS on every lifter’s phone and revolutionise fitness together.

Y Combinator, batch of 2025 and 2026
Y Combinator, batch of 2025 and 2026

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12Reps Team

The 12reps app is your ultimate fitness companion, crafting tailored workout plans, tracking your progress, and keeping you motivated every step of the way. Whether you’re at home, in the gym, or on the go, our adaptable approach fits seamlessly into your lifestyle — providing the support and guidance you need to crush your goals and stay on track.
y combinator, batch of 2025 and 2026

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