Under the hood
How Astro actually works
Training rules pick every exercise, set and rep. The AI only writes his words.
- Plans built
- 301
- plans built
- People with an Astro plan
- 246
- people with a plan
Since 20 Jul 2026 · live from FitAstra, updated hourly
Your answers in. A real plan out.
This is a real Day 1 Astro built. Fixed training rules chose every move and number — a language model never writes your workout.
You told Astro
- Goal
- Lose weight
- Equipment
- None, at home
- Level
- Beginner
- Days
- 3 a week
Day 1 · Full Body
4-week plan
Bodyweight Squat
3 × 12-15 · rest 45s
Pushups
3 × 12-15 · rest 45s
Superman
3 × 12-15 · rest 45s
Crunches
3 × 15-20 · rest 45s
Decided by rules
- Which exercises
- Sets, reps and rest
- Which days you train
- What gets left out
Written by AI
- The plan name
- Astro's notes and daily insight
Checked against his voice rules, with hand-written fallbacks. Your plan never depends on the AI.
A week with Astro
He is not cheerful on a timer. His mood comes from what you actually did — so skipping shows, and so does coming back.
Mon
Trained
Happy
You trained.
Tue
Trained
Proud
Your squat went up.
Wed
Rest day
Rest
Planned rest day.
Thu
No workout
Worried
9 PM, streak alive, nothing done.
Fri
No workout
Sleepy
Two days without training.
Sat
No workoutSleepy
Still nothing.
Sun
TrainedProud
Back after 3 days off.
Astro · Thursday, 9 PM
Okay so. 6-day streak, 3 hours left, nothing logged. I'm not panicking, YOU'RE panicking.
Missed a session? One tap moves it to a rest day later that week, or drops it for the week — free. With FitAstra Pro you can tell him why (too hard, no time, gym closed, sore) and he rebuilds the week around that reason.
The limits he works inside
- 1
A realistic weight goal
Weight loss is held to 0.5–1 kg a week (up to 1% of body weight for heavier people); weight gain to 0.25–0.5 kg a week. Ask for faster and Astro offers a deadline you can actually hit.
- 2
Injuries and health conditions shape the plan
A condition caps the intensity and removes movements that put it at risk, and some conditions show a doctor-clearance check before a plan is built. The condition itself is never stored — only the training limit, in plain words.
- 3
Food numbers with a floor
Astro gives a daily calorie and protein target, never a meal plan. It never goes below your resting metabolism, and for pregnancy, heart conditions or recent surgery he gives no number at all — that comes from a doctor.
- 4
Only the equipment you have
Home and dumbbell-only plans never ask for a pull-up bar, bench or machine. With nothing to pull with, the week is split into upper, lower and full-body days instead of push and pull.
- 5
Offers, not surprises
Moving you up a level is an offer you accept, never automatic. With FitAstra Pro, every plan change he proposes is shown first and happens only when you tap to agree. He never changes a plan your coach assigned.
Astro gives no medical advice, and switches to a calm, safety-first mode when you mention pain, injury or illness.
Where the numbers come from
8,000 steps a day (7,000 at 60+)
Your daily step target. Benefit levels off around 8,000–10,000 under 60 and 6,000–8,000 at 60+.
Paluch et al., Lancet Public Health, 2022 — 15 cohorts, ~47,000 adults
+2,000 for fat loss
Added when your goal is losing fat, in line with 200–300 minutes a week of moderate activity.
American College of Sports Medicine (ACSM) weight-loss guidance
+1,000 a week for beginners
Your level sets how fast the target climbs, not where it ends. A beginner walking 3,000 is asked for 4,000, not 10,000 on day one.
Astro's own ramp (beginner +1,000, intermediate +1,500, advanced +2,000); benefit starts from ~4,000 steps — Banach et al., Eur J Prev Cardiol, 2023
0.5–1 kg a week
The fastest weight loss Astro will plan for.
Widely published sustainable-rate guidance; 0.25–0.5 kg a week for weight gain
What costs nothing, and what does not
Free, permanently
- Astro builds your training plan
- Your daily insight, every morning
- Post-workout recaps
- Streak nudges and reminders
- Your plan, history, personal records and stats
FitAstra Pro
- Ask Astro anything, any time
- Your plan adapts when your week does
- Swap a movement that hurts
- Train against Astro's plans
- Every new Pro feature on FitAstra
Passes are not on sale yet. When they are, prices will be on the Pro page.
Questions
How does Astro create a workout plan?
You tell him your goal (lose weight, gain weight, get stronger, build stamina, stay consistent, or your own words), the equipment you have, the days you can train and any injuries. Fixed training rules then choose every exercise, set, rep count, rest time and training day from that. A language model only writes the plan name and Astro's note.
Is the workout itself written by AI?
No. The exercises and numbers come from fixed training rules, so a bad day for the AI model can never produce a bad workout. The AI only writes Astro's words around those decisions.
How does Astro keep me consistent?
His mood is calculated from your real training: proud when you hit a best or come back, worried in the evening when your streak is at risk, sleepy after two days off. You also get streak reminders, a daily insight each morning, a recap after you train, and a one-tap way to move a missed session instead of losing it.
What happens if I miss a workout?
Astro asks whether to move it to a rest day later that week or drop it for the week — one tap, free. With FitAstra Pro you can also tell him why you missed it (too hard, no time, gym closed, sore) and he rebuilds the week around that reason, because each one needs a different fix.
Is Astro safe if I have an injury or a health condition?
Conditions cap the intensity and remove risky movements, and some show a doctor-clearance check before a plan is built. Astro gives no medical advice and switches to a calm, safety-first mode for pain, injury or illness. The condition name is never stored.
How fast will Astro let me lose weight?
0.5–1 kg a week, or up to 1% of body weight a week for heavier people. If your deadline needs more than that, he offers a realistic one instead of a crash plan.
Does Astro give me a diet plan?
No. He gives a daily calorie and protein target, never below your resting metabolism, and none at all for pregnancy, heart conditions or recent surgery. For a full meal plan, a verified FitAstra coach writes one with your weekly sessions.
Can I try Astro without downloading the app?
Yes. The free planner at fitastra.co/workout-plan builds a real starter week from the same engine — every exercise with sets, reps, rest and form cues — with no signup.