Your first 30 days with the Garmin Forerunner 165

Twenty minutes on the first evening. Everything the Forerunner 165 will tell you for the next month is built on a heart-rate trace, a satellite mode and a screen setting, and all three are decided here.

1. 1

   Put it where the sensor works

   A finger’s width above the wrist bone, one notch tighter than feels natural for the first week, sensor window clean. The Forerunner 165 has a 43 mm case and wants a wrist of about 146 mm or more to sit flat; on a smaller wrist it rocks, and a rocking sensor is the source of half the strange numbers in month one. See wrist and case size .

2. 2

   Set your maximum heart rate, or clear it

   Every zone, every training-effect score and most of the load figures hang off this one number. If you know it from a recent hard effort, enter it. If you do not, delete the age-based default rather than leaving it: a wrong maximum quietly miscounts every run.

3. 3

   Leave the GPS mode alone

   The Forerunner 165 has one satellite mode, which is one fewer thing to configure. Its 19 h GPS figure is the one to plan long days around.

4. 4

   Choose gesture or always-on, and mean it

   The Forerunner 165 has an AMOLED screen. Always-on is the single biggest drain after the GPS chip — the site’s battery guide takes a fifth off for it — and gesture mode is what the quoted 19 h assumes. Try gesture for a week before deciding it annoys you.

5. 5

   Build one data screen you will actually read

   Pace, heart rate, distance, time. Four fields, one screen, big digits. Everything else can be a second screen you swipe to when you want it. The stock screens show too much and you will read none of it at speed.

6. 6

   Load music now, decide about it later

   Music from the watch to earphones is convenient and expensive: on the one maker that publishes a figure, GPS with music is about a third of GPS alone. Load a playlist while the watch is on the charger, then treat it as a short-run feature until you have checked the battery planner for anything long.

7. 7

   Set up payments while you have your cards to hand

   Contactless payment from the wrist is set up in the phone app and needs a card and a passcode. It is a five-minute job that always seems to come up when you are twenty kilometres from home without a wallet.

Garmin’s training suite on the Forerunner 165 starts producing figures after the first run and the first night. These are the ones that arrive first, with what each one needs before it means anything.

• Body Battery — from the first night. A 0–100 reserve estimated from heart-rate variability, stress and sleep. It reads high in the morning and drains through the day; the shape is more useful than the number, and it needs about a week before the morning figure is worth comparing day to day.
• A VO2max estimate — after the first outdoor run of ten minutes or more with GPS and heart rate. It is a fitness proxy derived from pace against heart rate, so it is only as good as the heart-rate trace: a loose watch or a cold wrist produces a low number, not a slow runner.
• Recovery time — after the first workout. Hours until the next hard session, counted down from the last one. In week one it is a generic estimate; it sharpens once the watch has your fitness level.
• Training Effect — after each session, an aerobic and an anaerobic score from 0 to 5. Read it as “what this run did”, not as a grade.

The second layer of figures is where the Forerunner 165 earns its price, and where a new owner is most often misled — because each of them shows a value before it has the data to justify one. What follows is what each needs, on this maker’s system: the baseline takes about three weeks.

• Sleep score — meaningful after a few nights, but only if the watch is on your wrist at night. Everything overnight depends on that.
• HRV Status — Garmin says up to 19 nights before it reports a baseline; call it about three weeks. Until then the field says “calibrating”, and any readiness figure that leans on it is leaning on nothing.
• Load and status readouts — how much of the full Training Status and Readiness pair this generation shows varies by model; what this tier reliably gives you is Training Effect, HRV Status and the load history. The running-dynamics layer is on the full-suite watches.

By the end of the month the VO2max will have stopped jumping around and the Body Battery will have a recognisable daily shape. That is the point at which the watch starts to be describing you rather than an average person.

• Watch the trend, not the day. One low Body Battery or one poor sleep score is noise; a week of them is information.
• Wear it to bed or ignore the recovery half. HRV, sleep and the morning readiness all come from overnight data; without it they are guesswork dressed as numbers.
• A VO2max that drops in the first weeks is almost always the heart-rate trace improving as you learn to wear the watch, not fitness falling.
• Override it when you know better. The model cannot see that you moved house, sat on a plane or ran into a headwind — see training load and readiness, and how much to believe .

Two figures on the Forerunner 165 are worth writing down at the end of the month, because they are the ones you will compare against later: the fitness estimate and, if the watch shows one, the morning recovery figure. Everything else is a snapshot.

These are the Forerunner 165’s own figures, and the arithmetic the site’s battery guide applies to them. The quoted number is the best case; the settings you chose above decide which line you actually live on.

For a race, take a further fifth off for a cold day and then add your margin — or let the battery planner do the sum for the Forerunner 165 with your settings and your finish time. Everyday battery of 11 days means a charge roughly once a week.

The finder ranks the Forerunner 165 on the same figures this page uses. Its one-line verdict: The AMOLED entry point, and the one most runners should look at first.

Where it is strong

• A bright screen at a price that used to buy a monochrome one.
• Training readiness and sleep score, borrowed from the expensive watches.
• Music on the Music edition.

What it gives up

• No multiband GPS.
• Elevation is GPS-derived — the barometer is not exposed.

If any of that is news after buying it, the finder will show you what the trade-off bought you — and what sat next to it in the ranking.