GP Platform
Every Grossen Performance client, in person or online, trains inside the same system. Intake, screening, programming, nutrition, check-ins, habits, biofeedback, education. Built by the coaches who use it every day.



We built this because we couldn't find one that coaches the way we do.
Inside the Platform
Six parts. All connected. One app.
01 · Screen & intake
Before your first session, we map what your body does and how you're wired. Everything that follows is built on what we find.
02 · Train
Your programme block by block, session by session. Log in the gym, your coach sees every rep.
03 · Eat
Meal planning and macros built around your gut, hormone, and personality profile. Different targets for training days and rest days.
04 · Know
Everything we learn from your intake and screening becomes personalised guidelines. Yours to reference any time.
05 · Track
Daily habits, biofeedback over time, training PRs per lift. The long view of what's working.
06 · Learn
A video library from Dries and Agathe explaining the why behind every training, nutrition, and health decision you'll make.
First reactions
From right after release. The app has grown a lot since.
Hi Dries, firstly, the app looks impressive! Did you do it completely by yourself?
— Katja
I like the app quite a bit and the effort put in is obvious. Well done. It's very intuitive and has nearly all the features I could ask.
— Paul
Questions before you start
The answers we give before we're asked.
Both, essentially. GP Platform is a web app that runs in any browser, on phone or desktop. No App Store, no install. On iPhone or Android you can add it to your home screen and it opens like a native app. One login across every device.
Mostly, yes. Open the app once with connection and it caches itself. After that, you can view your programme, log your sets, and record biofeedback with no service. Everything you log queues up and syncs the moment you reconnect. Fresh data like a new coach reply needs connection.
Yes, in real time. Every set, check-in, biofeedback entry, habit log, meal. If it's in the app, your coach sees it and responds.
Your history stays accessible for 12 months after you cancel, in case you return. After that it's deleted. If you want it gone sooner, send us a note and we will take care of it.
Online clients sign the coaching agreement, pay for the package, and receive a login link by email. From there, the intake form, health state questionnaire, personality screening, and physical screening are ready to complete before your first call. In-person clients get the same flow after the onboarding session is booked, minus the physical screening, since we run that in the gym together.
Not yet. If you take the onboarding session and decide not to start full coaching, we send you the full report: intake, screening results, health and personality profile, body composition. Everything we would have used to build your plan, yours to keep.
Pick the coaching path that fits. The Platform comes with all three.