- Log every session with its type, start time, duration and your Borg rating (1 to 10) about half an hour after, plus the distance if your machine showed one and a note if something was unusual; VT sets the intensity (light, moderate or hard) from your Borg.
- Pick the type from the master list and keep using the same name.
- Mark a session as new to you when it is.
- Let the device bring the heart-rate stream when there is one; when there is not, your Borg carries the load.
Why the type matters
The engines add up Borg × minutes whatever the type, but the type keeps your history in one line, and the protein target counts your resistance training sessions. The master list at launch is cardio, HIIT, indoor cycling, indoor rowing, kendo, outdoor walk, resistance training, swimming and yoga, and you can add your own; a session logged as "ride" one week and "indoor cycling" the next is two histories instead of one. For lifting, where the heart-rate stream under-states the effort, the Borg rating is the load that counts.
Why the Borg matters more than the watch
A heart-rate stream gives Cardio Load; a Borg rating gives the session-RPE load, which every engine reads, because every session has it (see Perceived exertion). Every training VT records carries a Borg: yours, Apple's Workout Effort, or, for a device that gives none, one VT works out from the session's heart rate; yours is the one to trust.
Why "new to you" matters
A session of a kind you have not done before, or not for a long time, costs more than its number says: the soreness is larger, the overnight readings move more, and the energy engine treats a hard or unfamiliar session as a confounder on the following day. The flag tells VT to read it that way.
What the log feeds
The TDEE engine's activity term (from session-RPE load); the load side of Capacity; the Symptom Radar training confounder, measured against your own training goal; Cardio Load and the energy-sources split, from the heart-rate stream; and the training timeline, which is where a plan meets a record.
What not to do
Do not log a walk to the shops as a session; that is what Activity Units are for. Do not type a 6-to-20 Borg number into VT's 1-to-10 scale. Do not log the same session twice when both the watch and you record it; VT shows you the device's session to attach your rating to.
Sources
- Vitality Tracker, What VT measures (catalogue of 15 October 2026: trainings, session fields, the novel-session flag)
- Foster C, et al. J Strength Cond Res 2001;15:109–15 (PMID 11708692).