> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nexrex.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# NexRex on Apple Watch
> Start a run, log water, weigh in, and check in on recovery from your wrist.
The NexRex watch app puts the four things you do most often on your wrist.
Open the app when your phone is away or mid-workout and everything you log
syncs back automatically — even if the watch is out of range.
## What you can do from the watch
Idle, the watch shows a 2×2 launcher. Each tile carries a live subtitle so
the screen is useful before you tap it.
| Tile | What it does | Live subtitle |
| ----------- | ---------------------------------------------------------------------------------- | -------------------------------- |
| **Run** | Opens the existing pre-run flow — pick a planned session or start a free/pace run. | Today's plan, if any. |
| **Water** | Quick-add hydration and see today's ring. | Today's total vs. goal. |
| **Weight** | Dial in a weigh-in (and optional body fat) with the digital crown. | Your last weigh-in. |
| **Recover** | One-tap "feeling good" or report a sore zone. | Whether you've checked in today. |
The Run tile is unchanged — it pushes the same pre-run screen NexRex has
always shown. This page focuses on the three new health tiles.
## Logging water
Tap **Water** to open the hydration ring for today. Under the ring are three
quick-add buttons:
* **+150**
* **+250**
* **+500**
Amounts follow the unit preference you set on your phone (ml or oz). Each tap
adds that amount to today's total and updates the ring immediately.
The ring uses an optimistic overlay, so it never rewinds between your tap
and the phone's echo. If you tap out of range, the amount is still applied
locally and syncs when the phone reconnects.
### Adding the hydration complication
You can put today's hydration on your watch face so you never have to open
the app to check where you are.
1. Long-press your watch face and tap **Edit**.
2. Swipe to the **Complications** page.
3. Tap a slot and pick **NexRex — Hydration**.
4. Press the crown to save.
The complication is available on circular, corner, inline, and rectangular
slots and shows today's amount against your daily goal. Tapping it opens
straight to the Water screen. The ring empties automatically at local
midnight, even if your phone hasn't checked in yet.
The hydration complication requires watchOS 9 or later. The watch app
itself runs on watchOS 8, so older watches still get water, weight, and
recovery logging — just without the face complication.
## Logging a weigh-in
Tap **Weight** to open the crown dial. The dial seeds to your last synced
weigh-in so most weeks you only nudge it a few tenths.
* **Turn the crown** to step by ±0.1 in your display unit (kg or lb).
* **Tap the value** to give the dial crown focus if you've switched focus to
the body-fat row.
* Tap **Log** to save. The value is converted back to kilograms behind the
scenes, so an imperial user can dial pounds and the same reading appears
on the phone.
### Body fat (optional)
Below the weight, a smaller dial edits body-fat percentage. To include it in
this weigh-in:
1. Tap the body-fat row to move crown focus to it.
2. Turn the crown to dial a value between **2%** and **60%**.
3. Tap **Log**.
Body fat is only sent when you've explicitly dialled it — a plain weigh-in
won't invent a reading. The last body-fat value on the phone seeds the row
the next time you open the screen.
Weight and body-fat entries land on the same daily health-metrics feed as
the rest of your NexRex data, so a wrist weigh-in shows up on your weight
chart, in weekly summaries, and against your weight goal — no separate
reconciliation required.
## Checking in on recovery
Tap **Recover** for a daily recovery check-in.
### Clear day
If nothing hurts, tap **Feeling good**. That records a clear check-in for
today and closes the screen. Do this every morning — a run of clear
check-ins is what powers your recovery trend.
### Reporting soreness
To flag a sore area:
1. Scroll to the zone that hurts — quad, hamstring, calf, achilles, knee,
IT band, glute, hip, shin, ankle, foot, or lower back.
2. Tap the zone.
3. **Pick a side** — Left, Both, or Right. (Lower back has no side picker.)
4. **Turn the crown** to dial severity from **1** (barely noticeable) to
**10** (can't run).
5. Tap **Log**.
The zone plus side compose into the same body-part label the phone uses
(for example, *right quad*), so a wrist check-in and a phone check-in show
up as the same entry — you can start on one and finish on the other without
duplicates.
Reporting soreness overwrites any earlier soreness value for the same zone
today. Log the worst reading you've felt in the day.
## Offline sync
Everything you log from the wrist queues locally and delivers exactly once.
* **Out of range?** Tap anyway. The log persists on the watch and delivers
as soon as your phone comes back.
* **Cold-start replays** can't double-log — each entry carries a client-side
ID and NexRex dedupes on it end-to-end.
* **Failed writes** stay queued and retry. A tap only clears from the queue
after the phone has successfully written it to NexRex.
You don't need to do anything to "flush" the queue — leave the phone on and
your logs land in the background.
## Setting your goals
The watch reads goals but doesn't edit them. To change your daily targets:
* **Daily water goal** — **Settings → Performance & Goal → Nutrition &
health goals** on the phone.
* **Weight goal** — same screen, under **Weight goal**.
* **Units** — **Settings → Units** on the phone. The watch picks up your
choice automatically.
See [Nutrition tracking](/athletes/nutrition#setting-your-nutrition-and-weight-goals)
for the full goal-editor walkthrough.
## Troubleshooting
Open NexRex on your phone once so the watch can pull a fresh snapshot.
Values update automatically after that as long as the phone is reachable.
Make sure you're on watchOS 9 or later, the NexRex app has been opened
once on the watch, and you've logged at least one drink today. The ring
resets to zero at local midnight.
Open NexRex on the phone with the watch nearby — the queue drains as
soon as the pair is in range. Force-quitting the phone app can delay
delivery until the next launch.
Body fat is only sent when the body-fat row has been dialled. Tap the
row to focus it, turn the crown to set a value, then tap **Log**.