How to start a Combined Load Planner for Lifting and Running business: plan and growth

People combining heavy lifting with run clubs fight constant leg fatigue and don't know how to balance recovery across two types of load on the same muscles.

A business built on a complaint people already posted in public.No. 035

An owner can start “Combined Load Planner for Lifting and Running” from a complaint people already posted. The offer, in one line: See strength and running load on the same muscles together, and know when to back off one. It is for hybrid athletes and runners. Charge a free tier and a paid upgrade, and test a price under $10 a month. Begin in more than one country. Buyers already talk about this in r/xxfitness. One thread gathered 35 votes and 33 replies across Sep 14, 2026 – Oct 14, 2026. Use that room to meet the first twenty buyers. Do not export it, and do not republish the posts. The idea, the evidence, and the market estimate on this page are free to read. Two paid prompts finish the job: one drafts the offer, the price, and a ninety-day calendar; the other drafts a month of conversations and proof. One credit unlocks both. A software specification is not on this site. When the company is the product itself, a single link further down opens the founder library.

Balancing heavy lifting and road running, how do
r/xxfitness · Sep 14, 2026 – Oct 14, 2026 · 35 votes · 33 replies · Open the thread

Who would pay

Hybrid athletes and runners. Start in more than one country, and charge a free tier and a paid upgrade, testing a price under $10 a month.

The thread above is the public complaint this business can learn from. Verbatim quotes are not invented. Further sources, when a later report adds them, stay with the evidence.

What buyers use today

  • Strava
  • Hevy
  • TrainingPeaks

The offer, in our words

A calculator/planner that merges strength and cardio load per muscle group and tells you when to reduce intensity in one discipline.

Score 2.75, Simmering. Pain, willingness to pay, demand, and the gap in current options drive it. We are not scoring how fast you can code.

Market size

An estimate, built from the bottom up: real customer counts × a realistic price. It shows the size of the prize, not a forecast.

TAM Total addressable

$228M a year

3.8M athletes · 5% of US gym and studio members

SAM Serviceable

$45.6M a year

760,000 athletes · app-store reach in the US

SOM Obtainable in 3 years

$456K a year

7,600 athletes · 1% of the reachable segment in three years

What that means

7,600 athletes at $5/mo = $456K ARR

Low confidence · estimated Oct 2026

How we estimated this
  1. Base: 77,000,000 US gym and studio members.
  2. Has the problem: 5% (assume 5% both lift and run seriously).
  3. Revenue per athlete: $60 per year ($5/mo).
  4. Reachable: 20% (app-store reach in the US).
  5. Three-year capture: 1% of the reachable segment.

TAM is customers with the problem × revenue per customer. SAM is the part a new business can reach. SOM is a cautious three-year share of SAM. The bars use a log scale. A share marked “assume” is our judgment, not a measurement.

Source: Health & Fitness Association, 2025 consumer report

The business-plan prompt

The offer, the price, and a ninety-day calendar, written for an agent. 1 credit unlocks both prompts for this idea: this plan and the growth playbook below.

plan.md · 624 words
# Business plan prompt: Combined Load Planner for Lifting and Running

You are writing a practical plan for one owner who will sell this as a business. Do not write a software specification, a venture memo, or a feature list. Use short sentences. Where a number is unknown, give a range and say what to measure.

## The business
Working name: Combined Load Planner for Lifting and Running
What the customer gets: See strength and running load on the same muscles together, and know when to back off one.
Who pays: Hybrid athletes and runners

Locked · the first lines are above

Unlock both prompts for this idea · 1 credit ($9.99)

One credit opens the business plan and the growth playbook together, for good. Credits work on both businessideastobuild.com and realstartupideas.com.

Sign in once with your Real Startup Ideas account; the same credits work on both sites.

Packs from $4.90 a credit, or $499 a year for everything

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The growth playbook

Thirty weekdays of conversations and proof. Not an ad plan. Included with the plan above, on the same credit.

growth.md · 463 words
# Growth prompt: Combined Load Planner for Lifting and Running

You are planning thirty days of distribution for a business that already has an offer. The offer: See strength and running load on the same muscles together, and know when to back off one. The buyer: hybrid athletes and runners. Price band: under $10 a month.

Do not propose ads, a viral loop, or a rebrand. Propose conversations, proof, and a repeatable weekly rhythm.

## Starting point
A public thread in r/xxfitness drew 35 votes and 33 replies. The pain, in the owner's words: People combining heavy lifting with run clubs fight constant leg fatigue and don't know how to balance recovery across two types of load on the same muscles.

Locked · the first lines are above

Unlock both prompts for this idea · 1 credit ($9.99)

One credit opens the business plan and the growth playbook together, for good. Credits work on both businessideastobuild.com and realstartupideas.com.

Sign in once with your Real Startup Ideas account; the same credits work on both sites.

Packs from $4.90 a credit, or $499 a year for everything

Questions

How much money do I need to start?

Enough to talk to buyers and deliver the offer once. A service version can start with a written process and a way to take payment. A software version is a larger bet and is not required to test the price. The band to test is Under $10 a month.

How should I price it?

Test a price under $10 a month, charged as a free tier and a paid upgrade. Raise it after three paid pilots, not before the first conversation.

Where do the first customers come from?

r/xxfitness is the clue. A related thread gathered 35 votes and 33 replies. Show up there, follow the room's rules, and ask for conversations. Do not scrape it.

Do I need to write code?

No. The prompts on this page draft a plan and a month of growth. Code is a later choice. The founder site linked once below is where the build document lives, if you want it.

The coded version, and the option to hire it out, are on the founder site. Have this built

A two-week build starts at $10,000 on that site, after a $1,000 scoping fee.

Plans and growth playbooks

One credit opens both prompts for this business.

The idea, the evidence, and the market estimate stay free. The business plan and the thirty-day growth playbook for Combined Load Planner for Lifting and Running cost one credit, together, and stay unlocked.

Credits work on both businessideastobuild.com and realstartupideas.com. Sign in once with your Real Startup Ideas account; it is the same wallet.

The agent PRD for this idea is on Real Startup Ideas →

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