SomviaWhat training load means
A session's load is a single number for how much it asked of you. Distance does not answer that question: an hour easy and an hour of intervals are the same hour and not the same demand. Load weights time by intensity, so the harder hour scores higher, and the numbers add up across sessions of different kinds.
Somvia estimates load from the heart-rate record of each workout, and where a session has power or pace curves it uses those too. Rides, runs, swims and strength sessions all reduce to the same scale, which is what makes a week comparable to the week before it.
Long-term load, and what this week is doing to it
Two averages of that daily load carry most of the meaning:
- Long-term load is the long average, about six weeks of daily load. It moves slowly, which is the point: it is what you have built rather than what you did yesterday.
- This week's volume is the short average, the last seven days. It moves quickly, and it is the one that runs ahead of you.
Read together they answer a question a single number cannot: is this week's work adding to what you have, or is it going in faster than you are absorbing it. Somvia charts both on one plot, with the value from four weeks ago in the corner so the direction is visible without reading the axis.
The eight training states
The two averages, plus whether your cardio fitness estimate, threshold pace and heart-rate recovery are improving or slipping, place the last few weeks in one of eight states: Productive, Maintaining, Peaking, Recovery, Unproductive, Detraining, Overreaching and Not enough data.
The words matter more than the number. "Maintaining" after three weeks of building is a plan working; the same word after two weeks of trying to build is a signal that the load is not landing. Somvia writes the reason under the word rather than leaving you to guess it.
What it needs
Workouts in Apple Health with heart rate recorded. That is the whole requirement, and it is met by an Apple Watch, by most third-party watches that write to Apple Health, and by a phone-recorded workout paired with a chest strap. No overnight wear is needed, which is why load and training status appear before the recovery score does.
A note on history. Somvia reads up to 180 days of Apple Health the first time it runs, so a full picture of long-term load is available immediately rather than after six weeks of using the app.
Where the method comes from
Load per session follows Banister's training-impulse approach, weighting duration by heart-rate intensity; the stress scores use the pace and power formulations that came out of Coggan's work. Long-term load and this week's volume are the exponentially weighted averages of that daily load. In the Performance Manager terms that TrainingPeaks and many coaches use, long-term load is chronic training load (CTL) over 42 days and the seven-day average is acute training load (ATL), both in training stress score units. Sources and what each model needs are on how the scores work.
Questions
Is this the same as Garmin's training load?
It answers the same question and is built from the same family of models, but the numbers are not interchangeable. Every vendor scales load differently, so compare Somvia with Somvia over time rather than against a figure from another device.
Do I need an Apple Watch?
No. Any workout in Apple Health with a heart-rate record can be scored, whichever device or app wrote it. Overnight wear only matters for the recovery, sleep and HRV readings.
Why does my long-term load drop during a taper?
Because long-term load is an average of recent daily load, and a taper lowers the load on purpose. Falling long-term load with a sharper drop in the last seven days is what a taper is supposed to look like, which is why Somvia reads the two together instead of alarming on one.
Is long-term load the same as CTL?
Yes. Long-term load is chronic training load (CTL), the 42-day exponentially weighted average of daily training stress score. The seven-day average behind this week's volume is acute training load (ATL). The app does not show training stress balance (TSB, yesterday's CTL minus yesterday's ATL), but a connected AI Agent can read all three over MCP.
What happens to a workout with no heart rate?
It still counts as a session with its duration and distance, but it cannot be given a load, so it does not move the long-term load. Somvia says which sessions were skipped rather than guessing an intensity for them.