Meet Lucia · your AI coach

Say what you lifted.
Lucia does the rest.

Kettle is a training app you talk to. Tell Lucia what you just did — "bench, 100 kilos, eight reps" — and it's logged. She keeps your history, watches your volume, calls your personal bests, and reshapes your plan around the sessions you actually trained. No forms. No spreadsheets. No guessing what to do next.

873
Exercises indexed
104
Sourced answers
On the App Store
Hear her Lucia, on a call
Kettle.
Your training at a glance
Lucia Online
"Build me a 4-day split"
This week
4sessions
Streak
12days
Volume
12.4kkg
PRs
7total
Muscle heatmap Week14dMonth
OverOptimalUnderUntrained
Recent
Lower Body BTue · 18 sets
Upper Body ASun · 16 sets
Lucia
Upper Body A · 24:18 elapsed
LIVE
Start my upper body session
Starting workout
Upper Body A
Today4 exercisesACTIVE
1Bench Press4 ×
2Incline Dumbbell Press3 ×
3Barbell Row4 ×
4Cable Fly3 ×
You're in. Bench first — last week you hit 97.5 for 8, so let's open at 100.
Bench 100 for 10
Logging set
Set 3 · Bench Press
10 reps @ 100 kg
Logged — and that's your best set at 100kg. Two more reps than April.
New PR · Bench press
100 kg × 10 reps
What's next?
Incline dumbbell press. Rest two minutes first — I'll count it.
Up next
Incline Dumbbell Press
3 × 830 kgChest · Front delts
Message Lucia…
How it works

Three things.
That's the whole app.

Most training apps make you their data-entry clerk. Kettle flips it: you talk, and the record keeps itself.

1

Tell her what you did

Type it or say it out loud, the way you'd tell a training partner. Lucia understands sets, weights, reps, drop sets and rest — in plain English, in your units.

"Squats — 5 sets of 5 at 120, last one felt heavy."
2

She keeps the record straight

Every set lands in your history the moment you say it. Volume, streaks, personal records and your muscle heatmap all update themselves — nothing to reconcile later.

"Logged. That's 2,400kg on legs this week — up 9% on last."
3

She adjusts the plan

Lucia reviews your programme against what you actually trained, then proposes the changes in writing. You accept them, or you don't. One tap either way.

"Your pull volume is lagging. Add a row to Upper B?"
Your coach

Not a chatbot with a fitness prompt.

Lucia has real access to your training data and can change it — the same buttons you have, driven by conversation. Here's what she can actually do.

Runs the session

Starts your workout, adds exercises on the fly, logs and corrects sets mid-flow, times your rest, and closes the session out when you're done.

Remembers everything

Ask what you benched in April, or how your squat has moved this quarter. She reads the same log you do — every session, every set, since day one.

Builds real programmes

Multi-week plans she creates, renames, reorders and rebalances on request. Or start from one of 30 ready-made plans and let her tailor it to you.

Catches every PR

Heaviest set, most reps at a weight, best estimated one-rep max. Called out the second it happens — not buried in a monthly summary you'll never open.

Reads your volume

Weekly tonnage per muscle group and how it's trending, plus a heatmap of what you've overcooked and what you've quietly been avoiding for a month.

Talks back, out loud

Call Lucia and work through the session hands-free — useful when your hands are chalked, your phone's on the floor and you're three sets deep.

Pro
In the app

And when you'd rather just tap.

Everything Lucia does, you can do by hand. The conversation is an option, never a requirement.

Muscle heatmap

Over, optimal, under — at a glance

Personal records

Every lift, every milestone

Volume trends

Session by session, week by week

873 exercises

Cues, muscles worked, your history

Lock screen timer

Live rest countdown, no unlocking

Apple Watch

Log the set from your wrist

Evidence, not vibes

Every answer shows its working.

Ask a general-purpose AI about protein and you get a confident average of the internet. Ask Lucia and you get a reviewed answer with the papers attached — 104 of them, across 12 areas of training, nutrition and recovery. Each one is dated, sourced, and honest about where the evidence runs out.

104
Reviewed answers
12
Research areas
100%
Carry sources

Strength & muscle

Training frequency, effective volume, proximity to failure, and how much of "more is better" the evidence actually supports.

Nutrition & fat loss

Protein targets, deficit sizing, nutrient timing, and which of the timing rules survive contact with a controlled trial.

Programming

Periodisation, progressive overload that actually progresses, and how to structure a week you'll still be running in March.

Recovery & sleep

Soreness versus damage, when a deload earns its place, and sleep's measured effect on adaptation and injury risk.

Special populations

Pregnancy and postpartum, masters athletes, and training around a body that has its own constraints.

Cardio, supplements & pain

The interference effect, which supplements have evidence behind them, and when a niggle means see a physio, not push through.

A real answer, in full
How much protein do I need to build muscle?

"Aim for about 1.6–2.2 g per kg of body weight per day, split across 3–5 meals. Morton's 2018 meta-analysis in the British Journal of Sports Medicine found a plateau near 1.62 g/kg — beyond that, extra protein gave no measurable extra gain."

Attached to it: the paper, the ISSN position stand, the review date — and the caveat that most of this literature studied young, mostly male adults over 6–16 weeks. Lucia tells you that part too.

PubMed BJSM ISSN ACSM WHO
From the App Store

What people say once they stop typing.

5.0· App Store reviews

Just easier

I lose interest in the other apps where you have to keep manually adding your sets. I can just type my workouts in as I'm going along and the AI tracks everything for me and presents it nicely! Way faster workflow!

S
sirjkelly
May 1 · 🇬🇧

Takes all the thinking out of working out

After a busy day the last thing you want to have to do is try and plan your workout. This app not only takes the decision burden out the way but is able to tailor workouts to your exact needs and goals. Highly recommend.

P
Pilot Grape
Apr 30 · 🇬🇧

Science backed AI guidance

Unlike other tracking apps I've used, the AI chat feature helps me ask questions during my workout and it actually links the science research papers at the same time.

M
Munatida
Apr 28 · 🇬🇧

Love the AI assistant

It's simple to use and the AI feature helps a lot to get things done. I can add workouts easily.

M
Mr Blasco
Apr 30 · 🇬🇧

Easy and effective to use

Such an easy app to use and love the chat functionality. Been using it for a while and it's making my workout so much more efficient.

M
MathewzFilmzHD
Apr 30 · 🇬🇧

Great workout buddy

It's a very good app to track your workout, and the AI system assists with making planning your workouts while providing valuable information when needed.

A
ahdbgtvsjrv
Apr 25 · 🇨🇦
Pricing

Start free. Stay free, if it suits you.

The tracker, the exercise library, your history and the research answers cost nothing. You only pay when you want Lucia running the programme itself.

Free

Chat with Lucia and explore your training.

  • Full workout tracking and history
  • 873-exercise library with your PRs
  • Daily chat with Lucia
  • The full research library

No card, no trial countdown.

PlusMost popular

Let Lucia manage your training for you.

  • Everything in Free
  • Lucia-managed plans — she monitors, tracks and adjusts
  • Programme changes tailored to what you trained
  • A far higher daily message allowance

Monthly or annual, cancel any time.

Pro

Talk it out — voice calls with Lucia.

  • Everything in Plus
  • Hands-free voice calls, mid-session
  • Priority model access
  • Early access to new features

Current prices are shown in the app.

Your next session starts with a sentence.

Download Kettle, tell Lucia what you're training today, and let the record keep itself.