Why I’m building Fortiv
It wasn’t a discipline problem. It was an architecture problem.
I’m Harry — 44, one-person team behind Fortiv. Spring 2024, I reached for a pair of shorts I’d worn the summer before. They didn’t button. I told myself maybe they’d shrunk. They hadn’t.
172 lbs → 160 lbs. Fourteen weeks. Beer and fried cheese included.
The shorts
The mirror lies to you. You see yourself every day, so the change never registers — it’s gradual and cumulative, and the mirror’s in on it. Pants don’t play along. A friend’s scale in Boston confirmed what the pants already knew: 178 lbs, the heaviest I’d been since 2008. I’d spent two months in Brooklyn eating and drinking my way through the neighborhood, training whenever the mood struck. Living life and calling it balance.
The mistake
A year earlier I’d tried to fix this — and made it worse. No body composition tracking, just a scale. Protein was a guess. When the number didn’t move, I cut calories. Then cut more. I lost weight and felt worse, because muscle went with it. Muscle is expensive to keep — your body sheds it first when training and protein don’t give it a reason to stay. Lose muscle, and your energy expenditure drops, which breaks the deficit the diet was built around, which makes you cut more, which costs you more muscle. That’s not a willpower problem. That’s a design problem with legs. I’d built a plan for a version of me who didn’t exist, then wondered why I couldn’t stick to it.
What changed
April 2025: I found zone 2 cardio and got strict — no drinking, no eating out, dead-consistent training and protein. It worked. By June I was the leanest I’d been as an adult. Then a friend came to visit. Dim sum, buffets, a week of undoing three months of habit — and I let it happen, because that’s what you do when a friend’s in town.
The lesson wasn’t about the food. A plan that only survives a life with zero variables in it isn’t a plan. It’s a streak. And streaks end.
That fall I ran a real hypertrophy block instead — structured training, eating enough to build, accepting I’d gain some weight back. By December I was heavier than June, carrying more muscle than I had at 178. And I finally understood what had gone wrong the first time.
Funny thing — I’ve got a photo from right around that 178 mark, mid-play, on stage. I remember looking at it afterward and blaming the lighting. Turns out the mirror wasn’t the only thing lying to me.
The receipts
14 weeks · Dec 2025 – Mar 2026
Beer most weeks. Fried cheese more than once. Training weeks I’d generously call light. Not one macro tracked precisely. The results didn’t happen despite the imperfection — they happened because the plan was built to survive it. The rule that made it possible: no changes until the trend holds for two full weeks straight. Not one bad day. The trend.
What I built
After those 14 weeks, I went looking for an app to keep running this. Couldn’t find one. Every app wanted precise tracking or a perfect streak — and the moment you slipped, it either flagged the miss in red or auto-adjusted your plan for you, which defeats the entire point of waiting for a real signal instead of reacting to one bad day. None of them had a category for showing up imperfectly and still winning. Odd, given that the people fighting this hardest — adults 35 to 55 — are the group every fitness app still designs around ignoring.
So I built one, alone, and I’m still building it. Fortiv tracks your strength, your zone 2, and your adherence against your own plan. When you start to drift, it doesn’t hide it and it doesn’t panic on your behalf — it surfaces one lever to pull, and you decide whether to pull it. It never auto-adjusts anything without you. That’s the whole app.
Last month I put on the same shorts from 2024. They fit — looser, actually. The shorts didn’t change. I did — because this time I was honest about who I actually am on a Tuesday in February, not who I want to be on January 1st.
If that sounds like you—
get on the list. I’d rather have your feedback than your signup.
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Built by a 44-year-old who started over one too many times.
Read the full, uncut version of this story on Medium.