What is strain (training load), and how much is too much?
Strain, also called training load, is a measure of how much cardiovascular and muscular stress you accumulate over a day — from workouts and from everyday activity. It's usually derived from time spent in each heart-rate zone. Tracking strain against your recovery is the core of smart training: match hard days to high recovery, and keep easy days genuinely easy.
How strain relates to recovery
Strain and recovery are two halves of the same loop. A high-strain day should be followed by lower strain until recovery rebounds; chronically stacking high strain on low recovery is how overreaching and injury start. The goal isn't maximum strain every day — it's the right strain for the readiness you have.
How Vita uses strain
Vita reads your WHOOP strain and Apple Health workouts and heart-rate data, and pairs your training load against your daily Recovery score so the AI coach can tell you whether today is a push day or a pull-back day — turning two separate numbers into one decision.
FAQ
Is higher strain always better?
No. Strain is only useful relative to recovery. Consistently high strain on low recovery leads to overreaching; the aim is to match load to readiness.
Does everyday activity count as strain?
Yes — strain accumulates from all cardiovascular stress, not just workouts. A long stressful day on your feet adds load even without a formal session.
How does Vita know my strain?
It reads WHOOP strain directly, and infers load from Apple Health workouts and heart-rate zones for Apple-only users.