MuscleFlare
Adaptive training
for building muscle.
A plan built around your schedule and equipment. Exact targets for every set. The next session adjusted from what you actually lifted — and a plain-English reason every time it changes.
- See your full plan before signing up
- Plan, logging and progression free — no card
- Rules you can read, not AI guesswork
Today · session 2
Upper A
Chest press
Barbell Bench Press
4 × 6–10 @ 82.5 kg · 2 RIR
You completed 80kg for 10, 10, 10, 10 reps across sets with about 2 reps in reserve — the top of your range on every set. Add 2.5kg and work back up from 6.
- Seated Cable Row4×10–10 · 65 kg+ Reps
- Dumbbell Shoulder Press3×12–12 · 24 kg+ Reps
- Lat Pulldown2×8–12Baseline
How MuscleFlare works
01
Plan
A split built from your days, session length, equipment and experience. Weekly sets per muscle kept in a sensible range.
02
Train
Exact targets for every set, the weight you used last time, a rest timer and one-tap logging built for a phone.
03
Record
Weight, reps and — if you want — reps in reserve. Saved to your account; a dropped signal never loses a session.
04
Adapt
Next targets from what you actually lifted. Struggling, run down or back from a break? The session adjusts.
05
Progress
Estimated strength per lift, records, weekly volume against plan and consistency — numbers that answer questions.
Progressive overload, explained
You always know why today’s target is different
Your targets come from a deterministic engine — double progression with effort, stall and recovery checks — not from a language model. The same history always gives the same answer, and every target carries the numbers it was based on.
AI is used where it helps: the Flare Coach explains your plan and your progress in plain language, using the same numbers the engine produced. It never writes your programme.
Top of the rep range on every set
Add the smallest sensible load — 2.5 kg on a barbell, 1–2 kg on dumbbells — and drop back to the bottom of the range.
Inside the range
Same load, add reps until every set reaches the top.
Last set went to failure
Repeat the load and finish with a rep in reserve before adding weight.
Same load, no extra reps for three sessions
Take about 10% off and build back up. Grinding the same weight rarely breaks a stall.
You feel run down
One set fewer per exercise and no load increases today.
10+ days away
Repeat your last loads. 21+ days: about 10% lighter with a set fewer.
Built for the gym floor
One hand, one glance, next set
The workout screen is the product. Everything is a large tap target, nothing important needs typing, and a refresh or a dead battery mid-session loses nothing.
Target and last time, together
Sets × reps, load and effort for today, with what you did last session underneath.
Log a set in one tap
Values are prefilled from your target. Adjust with − / +, tap ✓, rest timer starts.
Smart replacement
Rack taken? Swaps are ranked by movement pattern, target muscles and the kit you have — with the reason shown.
Setup · Move · Cue
Three lines per exercise and a muscle map. No walls of text.
Records that mean something
Heaviest weight, more reps at a weight and estimated-1RM bests, checked against your full history.
Missed a session?
The plan runs in order, so the session you missed is the one waiting for you. Nothing is skipped.
Free tool · Muscle Potential
How much muscle is left to build — and how fast
Muscle Potential compares your fat-free mass with where drug-free lifters of your height and sex typically top out, then projects how the gap closes. Ranges, not false precision.
- How far you have come. Percent of typical natural potential and your height-normalised FFMI.
- What is left. Lean mass still available, with an honest low–high range.
- How fast. Expected gains year by year, adjusted for training age, sex and age.
- What to do next. The calorie, protein and training changes that matter at your stage.
Worked example · 178 cm, 76 kg, 17%, 1 year training
Potential
83%
Left to build
12.6 kg
Next 12 mo
+5.7 kg
Know your numbers
The calculators people use most
Body
FFMI Calculator
Fat-free mass index, normalised for height, with context bands.
CalculateNutrition
TDEE & BMR Calculator
Maintenance calories with three BMR equations compared.
CalculateNutrition
Protein Calculator
Daily protein and per-meal targets from the best current evidence.
CalculateTraining
One Rep Max Calculator
Estimated 1RM plus a full percentage and rep table.
CalculateBody
Body Fat Calculator
U.S. Navy tape-measure method, with a BMI comparison.
CalculateNutrition
Bulking Calculator
Surplus, rate of gain and calories for a lean bulk at your level.
CalculateFat-free vs fat mass · 12 weeks
Example dataKnow if it’s working
Charts that answer questions, not decorate them
Log weight, waist, body fat and your best sets in seconds. MuscleFlare turns them into answers — trend weight through the daily noise, lean versus fat, and whether your lifts are actually going up.
- Am I gaining weight — at the right rate?
- Is my waist growing faster than it should?
- Is the weight I gained muscle or fat?
- Is my strength still increasing?
Flare Coach
Ask why. Get an answer from your own training.
The Coach reads your plan, your logged sessions, your records and your check-ins. It explains what the engine decided and why, quotes numbers that were calculated first, and says so when your data cannot answer the question.
3 questions a month free. 200 a month with Pro.
Flare Coach
ExampleWhy is my incline press lighter today?
It stalled. You have done 30 kg dumbbells for 8, 7, 7 in each of your last three Upper B sessions, short of the 8–12 target. Today drops to 27 kg so you can build back up through the range.
- Your flat press is still climbing, so this is local, not general fatigue.
- Log reps in reserve on the last set — it makes the next call more precise.
Training is free. Pro explains it, and tracks what it’s doing to your body.
- Flare Coach, 200 questions/mo
- Fat-free vs fat mass from your check-ins
- Weekly rate vs your goal
- Advanced Potential Report
- Unlimited saved results
- CSV export
€5.00 / month, billed yearly (€59.99 / year)
or €9.99 / month · 7-day free trial · cancel any time
Trend
+0.19/wk
Goal
0.12–0.25
Verdict
On track
Inside your lean-bulk range. Keep calories where they are.
Methodology
Estimates you can trust — because they admit what they don’t know
Every calculator names its formula and where it stops being reliable. Every training target names the logged sets it came from. Deterministic rules do the deciding; AI only ever explains.
Kouri et al., 1995
Height-normalised FFMI and the natural ceiling
Morton et al., 2018
Protein intake for muscle growth
Mifflin–St Jeor, 1990
Basal metabolic rate
Hodgdon & Beckett, 1984
U.S. Navy body-fat method
Schoenfeld et al., 2017
Weekly training volume
Helms et al., 2014
Cutting rate and protein in a deficit
Guides
The evidence, without the noise
Body composition · 6 min
What is FFMI — and how accurate is it?
Fat-free mass index explained: the formula, height normalisation, what a good FFMI is for men and women, and how accurate it really is.
Muscle potential · 7 min
How much muscle can you build naturally?
What research says about the natural limit for muscle growth, how fast gains come in years one to five, and why your ceiling is a range.
Nutrition · 5 min
How much protein do you need to build muscle?
The evidence-based protein range for building muscle, cutting and maintaining, how to split it across meals, and the myths about upper limits.
Know exactly what to lift next session.
Six questions and you see the whole plan — sets, reps, effort and how each lift progresses. Save it free when you like it. No card, no trial clock.
Build my plan