The Karoo is the most open head unit on the market. Nothing on it decides what to ride.
Every brand the Karoo competes with ships software that has an opinion about your training. Garmin suggests a daily workout from your own history. Wahoo sells SYSTM. Hammerhead ships neither — and the Karoo doesn’t even calculate your own numbers, since FTP, power zones, heart-rate zones and rider weight all sync in from a platform you nominate.
That vacancy is deliberate, and it is the best thing about the device. Hammerhead competes on being open: ten linked third-party accounts, free .ZWO and .FIT uploads, and a public API anyone can build against. What it means for you is that the slot above the hardware is yours to fill, and whatever you put in it becomes your plan.
AdaptCycling writes to that public API. The difference is what’s upstream of it: a plan that rebuilds itself when a week falls apart, rather than a calendar you reschedule by hand. The full picture of how workouts reach a Karoo is in our guide to training with a Hammerhead Karoo.
Connect once. The week shows up.
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Connect Hammerhead
One authorization from your Hammerhead account. No Strava in the loop, no file exports, no third app in the middle. Your ride history starts syncing immediately.
02 / 04
Every ride gets read
Not the summary averages — the full recorded file, per second, going back six months. Karoo files arrive with every interval already lapped by the device, so the analysis reads what you held rep by rep instead of guessing where the reps were.
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A plan gets built around it
Your FTP is estimated from your own power curve, so there's no test to ride first. Periodization, weekly volume, and interval structure are solved from your history and your goal.
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The week lands on your Karoo
The next seven days go to your Hammerhead account as structured workouts, and the Karoo collects them the next time it's online. Targets are sent as percentages of FTP, so a session stays correct even if your threshold moves between the push and the ride.
What syncs in, and what gets sent back.
Most apps that read a Karoo stop there. The return trip — putting a session back on the device — is the half that saves you a subscription.
| Data | What it does |
|---|---|
| Ride files | Full per-second recording, every ride |
| Power & heart rate | Used to estimate FTP and track load |
| Interval laps | The Karoo marks every rep boundary itself |
| Structured workouts | Next 7 days, with interval structure |
| Target ranges | Sent as % of FTP, not fixed watts |
| Plan changes | Revised sessions replace withdrawn ones in place |
Rest days aren’t sent — an empty day on the device is the point of a rest day.
What the Karoo does well, and the one thing we can’t send it yet.
The good half
The Karoo is one of the better structured-workout displays on a bike. Before you start, it shows which zones the session targets and how long you’ll spend in each. During it, you get a customizable workout drawer, controls to skip or scale an interval, and a new lap opened automatically at every interval boundary — which is why your Karoo rides come back to us with their structure already marked. Paired to an ANT+ FE-C smart trainer, ERG holds the target for you.
The honest limit
We push .ZWO files, and Hammerhead’s ZWO importer accepts power and cadence targets only — heart rate exists on the .FIT path instead. So if you train to heart rate, our push isn’t the right route for you yet. Upload a FIT workout to the Hammerhead Dashboard instead; it costs nothing. The full explanation is here.
Because Hammerhead rejects a non-conformant workout file whole rather than importing what it can, every session we push is checked against its import rules first — so a single bad step gets caught here rather than costing you a day on the bars. If you’ve hit that from another source, the rejection rules are written up here. And if TrainingPeaks is what you’re paying for today, the side-by-side is here.
Quick answers.
Can I get structured workouts on a Karoo without TrainingPeaks?
Yes. Hammerhead's older smart-trainer article still says TrainingPeaks or a Dashboard upload are the only routes, but its more recent Workouts documentation is broader — workouts import from connected third-party accounts or through the Dashboard, and the Dashboard links ten services. AdaptCycling writes to Hammerhead's public API directly, so your plan appears in your workouts list without a TrainingPeaks subscription.
Which Karoo does this work with?
Any Karoo signed in to your Hammerhead account. Workouts are pushed to the account rather than to a specific unit, so the device picks them up the next time it connects to the internet — a Today tag appears on the session in the workouts list, and a notification shows in the Control Center.
Do I need Strava at all?
No. Hammerhead can be your only connection. AdaptCycling reads your rides from Hammerhead, analyzes them, builds the plan, and sends workouts back — the whole loop runs without a Strava account.
How far ahead does my plan appear on the device?
Seven days: today plus the next six. Unlike some platforms this is our choice rather than a Hammerhead limit — the API accepts any date — but a shorter window means fewer days a rebuilt plan has to rewrite. It refreshes every morning, so there's always a full week queued.
What happens to my device when the plan changes?
The session is replaced in place. If you miss a week, get sick, or ask the coach to rebuild, the revised workout overwrites the old one rather than being deleted and recreated, so there's no window where the day is empty. If a day becomes a rest day, the workout is withdrawn — you won't ride a session the coach has already retracted.
Do I need a power meter?
For our push, effectively yes, and we would rather say so plainly. We send .ZWO files, and Hammerhead's ZWO importer accepts power and cadence targets only — heart rate is available on the .FIT import path, not the ZWO one. Until we ship a FIT workout encoder, a rider training to heart rate is better served exporting a FIT workout and uploading it to the Hammerhead Dashboard, which is free. Everything upstream still works: we read heart-rate rides and build plans from them.
Does this cost extra?
No. The Hammerhead connection and workouts on your device are part of the free tier, alongside your training analysis and one active plan. The $15/mo Coach tier adds adaptive week rebuilding, the AI coach chat, and post-ride analysis.
Free training analysis · No card · ~3 minutes
Connect Hammerhead and see where your training actually stands.
Connect your rides and the coach reads your last eight weeks — intensity balance, ramp rate, what's working, what's holding you back — then drafts your training plan around it.
Free 14-day trial, no card.