Product Guide · Adaptive Training

Strava or direct? How TTM reads your wearable data

Most generic training apps connect through Strava. TTM goes direct to your device - Garmin Connect, Suunto App, or Coros Developer - and keeps the HRV, sleep, and recovery signals Strava strips out. Here is what we read, how the plan adapts, and why the routing matters for a mountain training plan.

Jakob Ulcnik
By Jakob Ulcnik, Founder of Train to Mountain
The short answer

A wearable-connected training plan turns each workout you log into an input for next week's plan. It reads the data from your watch - what you did and how your body responded - and adapts the upcoming sessions accordingly. The honest limit is that some things, like technical skill and objective hazard, the data cannot show.

Why static plans fail when life happens

The standard playbook for mountain athletes is brutal: a coach writes you a 12-week plan in a spreadsheet, you grind through it, you check off boxes. The plan does not know that Tuesday's intervals were impossible because you flew red-eye, or that Saturday's hike turned into a six-hour scramble with 1500 metres of vertical, or that you caught a cold and wrote off a week.

A static plan keeps prescribing as if none of that happened. The athlete either feels guilty for falling behind, or grinds anyway and arrives overcooked. Both outcomes are worse than the plan having no business being followed.

An auto-sync wearable training plan solves this differently. Every session your watch records is read into the algorithm within minutes of syncing. The next session, the next week, the next phase - all reshape around what you actually did, not what the spreadsheet said you should have done.

What TTM reads from your wearable

Whatever you train with - Garmin, Suunto, Coros, Apple Watch, Polar - your wearable records the same core signals. TTM reads them through the device platform's own developer API (Garmin Connect, Suunto App, Coros Developer), not through Strava as an intermediary. Five signals feed the algorithm. Each one drives a different part of the plan.

HR data
Heart rate stream
Time in each zone (Z1 through Z5) is the input that matters most. The algorithm uses heart rate to calculate the cardiovascular load of each session - your Mountain Training Score for the day - and to verify whether intensity targets were actually hit.
Duration
Total moving time
Drives the load calculation alongside heart rate. Long sessions accumulate more fatigue; short sessions accumulate less. Duration also feeds the Long Day Score - the algorithm tracks whether you have completed a recent summit-day rehearsal.
Vertical
Elevation gain
Vertical gain is a vertical-gain factor on the load calculation - mountain fatigue scales with how steep the day was. It also accumulates to the Vertical Capability Score, which tracks total climbing across the build.
Pace
Pace and distance
Contextualises the effort. Two athletes with identical heart rate profiles produce different fitness gains depending on whether they covered 8 km or 20 km. Pace also helps detect when terrain or pack weight changed the work done at a given heart rate.
Type
Activity type
Hike, run, ride, ski, indoor Stairmaster, gym strength - each gets a specific Activity Type Factor that scales the load up or down for mountain specificity. A hike with vertical earns more credit than a road run of the same heart rate profile.

Why TTM connects to your device directly, not through Strava

Most generic training apps use Strava as their data layer. It is the easy path - Strava already sits between hundreds of wearables and the broader fitness app ecosystem. For a mountain training algorithm, we chose differently. TTM connects to Garmin, Suunto, and Coros through each platform's own developer API.

The reason is the signals Strava strips out. When your watch syncs to Strava, the activity stream survives - heart rate, GPS, elevation, pace. What does not survive: heart rate variability (HRV), sleep data, training readiness scores, and the device's own load and recovery metrics. Those are some of the most predictive signals for an adaptive plan, especially at altitude. Going device-direct keeps them in the picture.

Practically, this means: if you currently sync your workouts to Strava, you can still use TTM. You just connect Garmin (or Suunto or Coros) directly to TTM instead of going through Strava. The setup is one OAuth tap. After that, every activity your watch records reaches the algorithm - plus the overnight HRV and sleep signals Strava would have left out.

How the plan adapts: four scenarios

Concrete examples are easier than abstract rules. Here are four common situations and what the algorithm does in each.

1. You missed Tuesday's VO2max session.
No Tuesday activity synced → algorithm protects Z2 base for the rest of the week → defers the high-intensity session to next week's slot, not bolted onto Wednesday → next week's load target adjusts down slightly to account for the missed work.
2. You did a surprise long mountain day on Saturday.
Your watch logs 6h hike, 1500m vertical, mostly Z2 with surges → fatigue spike (MFat) registers → recovery week pulled forward in the next 4-week block → Sunday's planned long session shortens, Monday becomes full rest.
3. Your data shows you are progressing faster than expected.
MF (Mountain Fitness) trending up faster than the Banister model predicted → adaptation signals (lower HR at same pace, higher Z2 ceiling) confirm it → the plan promotes you to the next phase a week early instead of holding you in base for no reason.
4. You go silent for a week (sick, work travel, life).
No activities for 7+ days → MFat decays, MF decays slower → algorithm protects the Z2 cardio sessions in the return week (highest priority), defers VO2max work, drops total weekly load to a manageable re-entry target. No "you fell behind, work harder" guilt.

The plan you complete shapes the plan you get. That is the difference between a static spreadsheet and a connected training app.

What your wearable cannot show

Honesty matters. A wearable is excellent for what you did - duration, intensity, vertical, type. It is silent on three things that still matter for training:

TTM's AI coach (Ridge) covers this gap with short conversational check-ins, not with another device to buy. After key sessions, Ridge asks how it felt, and that perceived effort is added to the data the algorithm sees. It is a deliberate hybrid: machine-readable data for the bulk of the picture, human-readable input for what the sensors miss.

Connecting your wearable

TTM connects directly to your wearable's own platform - Garmin Connect, Suunto App, or Coros Developer - through a one-time OAuth authorisation. Every new activity syncs into the algorithm within minutes, and activities going back several months are read in on first connection, which means the algorithm has historical context from day one - it does not start from zero. We read your data; we never publish back to your account.

One honest setup note: wrist-based optical heart rate can drift during hard intervals or in cold conditions, where accurate zone data matters most. If your training leans heavily on precise intensity work, a chest-strap heart rate monitor pairs with every major wearable and gives the algorithm cleaner data to work from.

For the deeper rationale on why heart rate zones (and therefore your wearable's HR data) matter so much for mountain athletes specifically, see our heart rate zones for mountaineering guide.

How TTM uses your wearable data, in one paragraph

The short version

The result is a plan that earns its name. Not a 12-week spreadsheet you tried to keep up with - an actual coach that read your week and adjusted.

Common questions

Which wearables work best with mountaineering training apps?

Garmin, Coros, and Suunto are the strongest fit for mountain athletes. They capture heart rate, GPS, elevation, and training load in a way mountain-specific algorithms can consume directly. TTM integrates with all three via their native developer APIs (Garmin Connect, Coros Developer, Suunto App).

Does TTM connect through Strava?

No. TTM connects directly to your wearable's own platform - Garmin Connect, Suunto App, or Coros Developer - through each one's developer API. Strava strips HRV, sleep, and training-readiness data that the algorithm uses, so we chose to bypass it. If you currently log to Strava, you can still use TTM by connecting your watch directly instead.

What is the difference between Strava integration and direct device integration?

Strava is a feed aggregator: workout summaries, GPS tracks, heart rate. Direct device APIs (Garmin Connect, Suunto App, Coros Developer) expose the full picture: workouts, HRV, sleep, recovery scores, training readiness, and device-side load metrics. For a training plan that adapts to your physiology, the extra signals are load-bearing - overnight HRV alone is one of the strongest predictors of what tomorrow's session should look like.

Can my Strava workouts auto-sync into TTM?

Not from Strava itself. But you do not need to: TTM auto-syncs the same workouts directly from Garmin, Suunto, or Coros, plus the HRV and sleep signals Strava does not pass through. The connection is one-time OAuth, and historical activities from the last several months are read in on first connection.

What does TTM read from Garmin, Suunto, or Coros that Strava does not expose?

Four things in particular: heart rate variability (HRV) - the strongest single overnight predictor of training readiness; sleep duration and stages; the device's own recovery and readiness scores; and richer activity streams (instant heart rate, instant pace, cadence). Strava receives the workout summary; the device platform retains the deeper physiology.

What data does TTM actually read from my watch?

Five signals drive the algorithm: heart-rate stream (zone time), session duration, elevation gain (vertical accumulation), pace and distance, and activity type. Each maps to a specific part of the load and readiness calculation - heart rate drives intensity, vertical drives mountain specificity, duration drives long-day capacity.

Do I need a chest-strap heart rate monitor?

Not required, but recommended if your training leans heavily on precise zone work. Wrist optical HR drifts during hard intervals and in cold conditions - exactly when accurate zone data matters most. A chest strap pairs with every major wearable and gives the algorithm cleaner data to work from.

Can a wearable detect overtraining?

The data signals are there - elevated resting heart rate, suppressed HRV, decoupled effort-versus-output - and TTM watches these trends across days, not just single sessions. What no wearable can show is perceived effort or life context, which is why TTM pairs the data with brief AI check-ins after key sessions.

How long after a session does my wearable data appear in the plan?

Within minutes for most watches, once the session syncs. The next morning's readiness score and the next week's session adjustments are calculated from data that hit the algorithm the night before. There is no manual upload step.

Connect your wearable. Get the plan that adapts to you.

Train to Mountain reads your wearable data automatically and reshapes each week of your plan around what you actually did. No spreadsheets to maintain. No guilt about missed sessions. Just the next best step toward your mountain.

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