Body Battery and strength training — stop guessing, start adapting

Body Battery aggregates HRV, sleep quality, and stress into a single 0–100 score. Most Garmin owners check it every morning — it's one of the most glanceable metrics the watch produces. And for good reason: it's a genuine proxy for physiological readiness.

But knowing your Body Battery is 54 doesn't tell you whether to do heavy compound lifts or active recovery. The number has no context. Should you squat at 54? Probably. What about 38? What if your HRV is suppressed at the same time? What if you've been accumulating training load all week? A single number can't answer these questions — and training blind to them increases injury risk and stalls adaptation.

Forma answers these questions by mapping Body Battery alongside HRV, sleep score, and training load ratio to a specific session type and a full structured workout prescription. You get a session that fits where you actually are — not where you planned to be.

Body Battery is one of five inputs Forma processes every time you generate a session. It contributes real signal — but it is never used in isolation. The engine combines Body Battery with HRV status, sleep score, training load ratio, and your recent session history to produce a single readiness verdict and a matched workout.

A Body Battery of 45 with balanced HRV and sleep score 78 maps to a completely different session than a Body Battery of 45 with low-unbalanced HRV and sleep score 55. The number is the same; the physiological picture is entirely different. Forma respects that distinction. All four signals together determine the prescription — not any single metric in isolation.

The result is one of five session types, each with a complete structured workout: exercise selection, set and rep targets, rest periods, and notes. Not a recommendation. A full session you can take into the gym or push directly to Garmin Connect.