How to get structured workouts on a Karoo without TrainingPeaks

The free route almost nobody mentions: upload the file

The Hammerhead Dashboard imports .ZWO and .FIT workout files directly. Add the workout, and the next time your Karoo reaches the internet it syncs across [Hammerhead Workout Import]. There is no subscription anywhere in that chain, and no partner list to appear on.

This is the answer to the literal question, and it has been available the whole time. If a platform can export a structured workout as a file — and most can, including free ones — that workout can reach your Karoo. Open the Dashboard, choose Workouts in the sidebar, click Add Workout, and drop the file in [Hammerhead Workout Import]. The forum answer that circulates for this question is that you have to recreate your sessions by hand in TrainingPeaks. You do not.

The rules the importer enforces are stricter than most exporters assume, which is why this route sometimes fails in a way that looks like a bug. For a .ZWO file, every step must be a warmup, cooldown, free ride, repeating interval, or steady state — maximum-effort and ramp steps are unsupported — and every step must carry a power or cadence target, with zone-based power targets rejected outright [Hammerhead Workout Import]. A file that breaks any of those rules is rejected whole rather than partially imported. If your export contains a ramp or an all-out effort, that single step is what stopped the whole session loading.

One rule decides more than the others. A .FIT workout's steps can target speed, heart rate, cadence, or power — heart rate and power as absolute values or percentages, speed and cadence as absolute values — and heart rate is not on the .ZWO list at all [Hammerhead Workout Import]. The two formats are therefore not interchangeable. If you train to power, export .ZWO or .FIT and it makes little difference. If you train to heart rate, only .FIT will carry your targets, and choosing the wrong export is the difference between a usable session and a set of numbers you cannot follow.

The honest limit of this route is that a hand-uploaded file is a snapshot. It does not change when your week does, and doing it every evening is a chore that quietly stops after a fortnight. It proves the device is not locked down. It does not solve the problem of keeping a plan current.

Connecting a provider instead, and which ones qualify

The Dashboard links ten third-party accounts: AXS, Intervals.icu, Komoot, Ride with GPS, Sentiero, Strava, Suunto, TrainerRoad, TrainingPeaks, and Xert [Hammerhead Account Linking]. Not all of them send workouts — several are route or activity destinations — but the list has not been a single name for some time.

The change worth knowing about is Intervals.icu, which now syncs with the Karoo directly. It is the option most likely to end this search for a rider who does not want another subscription, because its analysis is genuinely strong and its planning is free to use. For several years the only workaround was a community-built script that pushed workouts in unofficially, with a warning not to press Sync afterwards or they would be removed. That era is over, and pages describing it are describing 2022.

Xert is the other one worth naming, because it does something structurally different: it models your fatigue continuously and reshapes what it recommends rather than serving a fixed calendar. TrainerRoad appears on the account list and does real within-plan adaptation for indoor power sessions. TrainingPeaks remains the deepest structured-workout builder available and is where most coached athletes already work — if a coach writes your plan, moving it elsewhere to save a subscription just creates a second place for the truth to live.

What none of them is built to do is rebuild your next fortnight around the week you actually had. That is a different job from delivering a workout, and it is the one the Karoo ecosystem leaves open — Hammerhead ships no training platform of its own, which is the subject of our broader guide to training with a Hammerhead Karoo. The device renders a session extremely well. Deciding which session it should be was never any part of the chain's job.

Choosing a route when you don't want another subscription

Three cases, and the right answer depends on where your plan is authored rather than on price. Upload files by hand if your sessions are fixed. Connect a free provider if you want a calendar. Use something that reads your rides back if what breaks your plan is your life rather than your legs.

If your training is a repeating block you already know — the same four sessions on a six-week rotation — hand-uploading is entirely reasonable. Build them once, upload them once, and the Karoo holds them. The chore only bites when the plan is supposed to change.

If you want a calendar without paying for one, connect Intervals.icu and stop there. It costs nothing, it syncs, and it will do a better job of showing you what you have done than most paid tools. This is a real answer, not a consolation prize, and any page that tells you TrainingPeaks Premium is the only route to a week of workouts on a Karoo is out of date.

The third case is the one worth thinking about properly. Most amateur plans do not fail because the intervals were wrong. They fail because a work trip erased Wednesday, a chest infection took ten days, or a four-hour group ride on Saturday quietly made Tuesday's session a bad idea. A calendar cannot notice any of that, and neither can a file you uploaded last Sunday.

That is where AdaptCycling sits. We read your ride history from the source you already use, estimate your threshold from your own power curve rather than asking you to schedule a maximal test — the critical-power relationship makes that possible from efforts you have already ridden [Jones et al. 2010] — and build a plan from what you have actually been doing. When the week goes sideways, the plan is rewritten around it rather than left to rot. Rides recorded on a Karoo help here more than most, because the device opens a new lap at every interval boundary [Hammerhead Karoo Workouts], so the analysis reads what you held rep by rep instead of guessing where the reps were.

Quick answers

Sources cited in this guide

1. 01
   Hammerhead Karoo Workouts. Karoo OS - Workouts. Hammerhead Support.
2. 02
   Hammerhead Workout Import. Dashboard - Importing ZWO & FIT based Workouts. Hammerhead Support.
3. 03
   Hammerhead Trainer Support. Karoo OS - Smart Trainer Integration. Hammerhead Support.
4. 04
   Hammerhead Account Linking. Dashboard - Linking Third-Party Accounts. Hammerhead Support.
5. 05
   Jones et al. 2010. Critical power: implications for determination of VO2max and exercise tolerance. Medicine & Science in Sports & Exercise.

More inside Training with a Hammerhead Karoo

Other articles in this series

1. 01

   Training plan apps for the Hammerhead Karoo

   Hammerhead ships no training platform, so the app you connect is the plan. What TrainingPeaks, TrainerRoad, Intervals.icu and Xert each actually do.

   →
2. 02

   Intervals.icu to Karoo workout sync: how it works

   The official sync landed in January 2025 and is created from the Karoo itself. What syncs, what the importer rejects, and the format trap.

   →
3. 03

   Karoo workouts not syncing: how to find the real fault

   Check the Dashboard first — that one look halves the problem. The provider rules that block a push, the device half, and the failure that is not one.

   →
4. 04

   ZWO file not importing to a Karoo: the rejection rules

   Hammerhead rejects the whole file, not the bad step. The step types it accepts, the target rule, and the difference between rejected and ignored.

   →
5. 05

   Karoo structured workouts without a power meter

   A heart-rate strap satisfies the Karoo's sensor requirement, but heart-rate targets exist only in FIT. What HR can target, and what it cannot.

   →