I have been training strength for three years. I started the way almost everyone does: with a notebook and a pen. I wrote down the date, the exercises, the weight, and the reps. Simple, functional, good enough for someone just starting out.
But a few months of serious training and you realise the problem is not remembering what you did yesterday. The problem is knowing what to do next week, next month, and why.
The digital leap
I moved to Hevy. Clean app, well designed, solid exercise library. I liked it. Logging sets from my phone was much faster than the notebook. But Hevy does one thing very well: recording what you already trained. What it cannot do, at least not in any meaningful way, is tell you how to structure what you are going to train.
When I started reading about periodization, training blocks, chronic fatigue, and planned progression, I hit a wall. No training app available was built for that level of planning.
The spreadsheet
I did what everyone does when they take training seriously but do not have the right tool: I built a spreadsheet. First a simple sheet with weeks and blocks. Then another for accumulated volume. Then one for e1RM calculations. At some point I had three tabs open on the laptop while trying to log the session on my phone.
It was a system, but it was a broken one. The information lived in three different places that were never in sync. When a training block ended, reconstructing what had actually happened was more work than the training itself.
“I was between sets. The timer went off. I opened the spreadsheet on my laptop to check the day's prescription. I opened Hevy on my phone to log the set. And I thought: this cannot be the way.”
The idea, at the gym
A couple of months ago, mid-session, the idea hit me all at once. Not as an abstract insight. As a concrete, urgent need: I want one screen where I can see my block plan, understand which week I am in, log the set I just finished, and know whether I am accumulating too much fatigue.
I did not want another routine tracker. I wanted a training operating system. A tool that understood that today's bench press exists inside a session, the session exists inside a week, the week exists inside a mesocycle, and all of it has a direction.
Why I built it myself
I am a developer. So I did what I do when I cannot find the tool I need: I built it. I started with the feature that frustrated me most: block planning with a full hierarchy. Macro, meso, micro, session, exercise.
Then I added set logging with integrated RPE. Then the Banister fatigue model for a live TSB. Then five e1RM formulas running in parallel. Every feature came from a real need I had as an athlete, not from a list of things that would look good on a pricing page.
That is Synthrs. A tool I built for myself, that I now want to put in the hands of any athlete who thinks in blocks and real progression. If you have been feeling limited by your training app or lost inside spreadsheets, this is for you.