The Forerunner 970 delivers up to 20 days in smartwatch mode and up to 31 hours in standard GPS mode — sufficient for even the longest ultramarathon races. Multi-band GPS mode reduces runtime to approximately 16 hours, which still covers 100-mile ultramarathon finishers at competitive paces. The Solar charging variant adds passive solar energy collection that meaningfully extends battery life under direct sunlight, particularly relevant for long outdoor training blocks.

Garmin's battery saver GPS mode can extend GPS tracking time further by reducing update frequency — useful for ultra-distance events where absolute position accuracy is less critical than tracking direction and distance. The AMOLED display is the primary battery consumer in smartwatch mode; reducing display brightness or using Always-On judiciously will extend daily battery life. Charging is via Garmin's proprietary USB-C compatible clip.

The Forerunner 970 is the first Forerunner to include ECG, producing a 30-second single-lead electrocardiogram readable on Garmin Connect and shareable with healthcare providers. HRV Status monitors heart rate variability trends over time, providing a reliable long-term recovery and readiness signal used by elite athletes and sports physiologists. Body Battery synthesises HRV, sleep, and stress data into an intuitive 0–100 energy reserve metric updated continuously throughout the day.

Sleep tracking includes REM, light, and deep stage analysis, with a daily Sleep Score and Nightly Recharge metric that quantifies how well overnight recovery restored the Body Battery. Pulse Ox overnight tracking is specifically useful for altitude training camps, flagging insufficient acclimatisation. Garmin's Health Snapshot generates a resting health summary — heart rate, HRV, SpO₂, respiration rate, and stress — in under two minutes, producing a reproducible baseline for health trend monitoring.