04 · FITLive✦ AI
What is your training actually doing?
Log your weekly weight and measurements. See the trend line. Know your rate of change. Get AI coaching that tells you whether your current approach is working and what to adjust.
Weight trend · body fat % · 6 measurements · AI insight
Free · Every tool unlocked · No card
Weight + body fat trends at a glance.
Every weigh-in, kept forever.
§ How it works
01Log your weekly weigh-in
Enter your weight each week. Body fat % and 6 tape measurements are optional but add insight. One entry per week is enough.
02See your trend line
After 2 entries a trend chart appears with your rate of change per week and a dashed regression line. You see instantly whether you are on track.
03Track where the changes are
The Body tab shows all 6 measurements with deltas from when you started. Waist down while arms stay the same is a very different story to overall weight loss.
04Ask AI what your numbers mean
The AI reads your full history: weight trend, rate, fat %, and measurement shifts. It gives a direct assessment of whether your approach is working and one specific thing to adjust.
Most people who train consistently never measure whether it is working.
§ Related tools · these read this one, and this one reads them
§ Try it yourself · no signup, just play
Use Body Composition Tracker right here. No signup, no card.
Like it? Save your work and get the AI Coach.
Sign up free§ Frequently asked
How often should I log?
Once a week is enough to see a meaningful trend. Daily logging adds noise from water retention and digestion. Weigh at the same time each week, ideally in the morning before eating.
What is a healthy rate of change?
For fat loss: 0.25 to 0.75 kg per week is the optimal range. Faster than 1 kg per week risks muscle loss. Slower than 0.1 kg per week may mean you are at maintenance. The AI will flag if your rate looks off.
Do I need to log body fat %?
No, it is optional. Weight trend alone is useful. Body fat % adds context: particularly valuable if you are in a recomp phase where weight stays flat but fat % is dropping.
Which measurements matter most?
Waist is the most informative single measurement for body composition. Arms and thighs reflect muscle changes. You can log just the ones you care about: all 6 fields are optional.
Does it work offline?
Completely. All data saves to your browser's localStorage with no internet required. The AI coaching needs a connection, but the tracker, charts, and measurements work fully offline.