> ## 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.
# Health tracking
> Log water intake and body weight from the Home tab, and track trends alongside your training.
The **Health** section on the Home tab is your quick-access surface for daily
hydration and body-composition logging. Two cards — **Water** and **Weight** —
sit alongside the rest of your home cards, and each opens a full detail screen
with quick-adds, trends, and a Rex insight.
Water and weight logs are stored on the same health-metrics pipeline as resting
heart rate and HRV, so they inform your recovery signals without cluttering the
training calendar.
## The Home tab Health section
The **Health** section shows one row with two cards:
* **Water** — today's total, a progress bar toward your daily goal, and a
one-tap **+250 ml** quick-add.
* **Weight** — your most recent weigh-in, a 6-point sparkline of recent
entries, and your 7-day delta.
Tap either card to open its detail screen.
Weight and water values on the Home cards and detail screens display in your
preferred units. Metric shows kg and ml/L; imperial shows lb and fl oz.
Change units under [Account settings](/account/settings).
## Logging water
Open the Water card to reach the water detail screen.
### Quick-adds and custom amounts
The detail screen has three tap-to-log buttons for common vessels:
* **Cup** — 150 ml
* **Glass** — 250 ml
* **Bottle** — 500 ml
For any other amount, use the stepper to log between 50 ml and 1,500 ml in one
entry.
Every entry stacks into today's total. Tap **Remove entry** next to any row in
**Today's log** to take that amount back off — the total on the ring and the
Home card updates immediately.
The per-entry breakdown (each cup, glass, or bottle) is stored on your
device, so removing individual entries only works on the device where you
logged them. Your daily total syncs across devices.
### Setting a daily water goal
The progress ring shows how close you are to your daily hydration goal. Pick
your goal in one of two places:
* **From the water detail screen** — tap one of the **2.0 L**, **2.5 L**, or
**3.0 L** chips under the ring.
* **From Settings** — for a custom value, go to
**Settings → Performance & Goal → Nutrition & health goals** and edit the
**Daily water goal** row.
Your goal is applied instantly and shared across the Home water card, the
progress ring, and the weekly bar chart's dashed goal line.
### Weekly trend and Rex tips
Below today's log you'll find:
* **This week** — a bar per day for the last 7 days with a dashed goal line
and average per day.
* **Rex · hydration** — a short, contextual tip based on how far along you are
today (for example, a nudge to finish your remaining volume before 8 PM, or
a "goal reached" note reminding you not to over-drink before bed).
## Logging weight
Open the Weight card to reach the weight detail screen.
### Tap to type or step
There are two ways to log a weigh-in:
* **Tap-to-type** — tap the large weight value at the top of the screen and
type your reading (valid range: **20–300 kg** / equivalent lb).
* **Stepper** — use the stepper in the log section to nudge the value up or
down before tapping **Log weight**.
Logging today's weight again overwrites the day's entry, so re-logging after a
fresh reading doesn't create duplicate rows.
### Body composition — body fat and body water
If you have a body-composition scale (or an Apple Watch reading), you can log
optional body-composition percentages alongside your weight:
* **Body fat** — tap the **Body fat** value to type a percentage between
**2 %** and **60 %**.
* **Body water** — tap the **Body water %** field to type a percentage
between **45 %** and **75 %**.
Both fields are optional — a plain weigh-in never invents a reading — and any
value you enter is stored alongside that day's weight, so all three trends
stay in sync.
### Goal, deltas, and trends
The detail screen shows:
* **Hero value** — your latest weight, with a weekly-delta pill (for example,
*−0.4 kg this week*).
* **Goal progress** — driven by the target weight in your training goal.
Update it under
**Settings → Performance & Goal → Nutrition & health goals**, or from the
**Goal setting** screen.
* **30 / 90-day trend** — toggle between windows to see weight and body-fat
trends side by side, with high/low markers.
* **History** — the last several weigh-ins with day-over-day deltas. Rows
are interactive:
* **Tap** a row to open a bottom-sheet editor pre-filled with that day's
weight, body fat, and body water. Adjust any field and save to update
that day — this works for any past day, not just today.
* **Swipe left** on a row and confirm to delete that weigh-in. The row
disappears immediately; if the delete fails on the server, it comes
back and you'll see a retry prompt.
* **Rex · insight** — a short read on whether you're trending down, holding
steady, or need to fuel your long runs harder.
## Where water and weight show up
Because water and weight are health metrics — not activities — they don't
appear on your training calendar the way runs and manual notes do. Any logs
you made before this change are hidden from the week and month calendar views
so the calendar stays focused on training. The values themselves are still
available in the Water and Weight detail screens, and continue to inform
recovery insights.
Manual **recovery notes** you authored yourself still appear on the
calendar. Only automatic water and weight entries were moved off.
## Troubleshooting
Health tracking is rolling out gradually. If you don't see it yet, make
sure your app is on the latest version and check back after a Home tab
refresh.
Removing an individual entry only works on the device that logged it. If
another device also logged water today, its amount is still counted in
your daily total.
Weight must be between 20 and 300 kg (or the imperial equivalent), body
fat between 2 % and 60 %, and body water between 45 % and 75 %. Values
outside those ranges won't save.