Three prompt types do most of the work for a personal trainer: a session recap built from your own notes, a short check-in for clients who have gone quiet, and a renewal text sent before a session pack runs out. Give the AI your notes and a tone sample, leave names out, and ban medical and diet advice.
Retention is where these messages matter. A client who finishes a pack and hears nothing usually drifts away, and finding a new client takes far more of your time than a well-timed text. The renewal text is the one to get right: send it with two sessions left, state the price, and make "not now" an easy reply. All ten prompts below come with sample outputs and a quick test to run on your own client list.
Rules before any prompt
These five rules sit above every prompt. Paste them once into a ChatGPT or Claude Project (or the custom instructions in a plain chat) and each prompt gets shorter.
- No client names or contact details. Use [first name]. Add the real name when you send.
- No health data. Injuries, medical conditions, medication, pregnancy and weight go in no prompt. If the recap needs them, write that part yourself.
- No diet or medical advice, ever. The AI writes about attendance, effort, habits and goals the client set, not what they should eat or how to treat a pain.
- No invented results. Only numbers you supply. If you give no number, the message gives none.
- One next step per message. Book, reply, or confirm. Never three asks in one text.
STANDING INSTRUCTIONS (paste once):
You help a personal trainer write short messages to clients. Plain
British English, warm but not gushing, no emojis unless I add one,
no exclamation marks more than once per message. Never give medical,
injury or diet advice. Never invent numbers, results or dates; use
only what I give you. Use [first name] where a name belongs. Each
message has one next step. Keep texts under 60 words.Notice the tone line asks for "warm but not gushing". Without it, most models produce messages with stacked exclamation marks that read like marketing. Add two examples of your own past messages under "My style" and the output moves closer to your voice.
Prompt 1: the session recap from rough notes
After a session you have scribbled notes: what was done, one win, one thing to work on, what is next. The recap prompt turns them into a message in under a minute.
Write a session recap text to [first name]. Under 70 words.
My notes: did lower-body session, squats up from 40kg to 45kg for 3x8,
form better on the last set, tired on lunges, next session upper body,
reminder to book Thursday.
Include one specific win, one thing we'll keep working on, and the
next session. No advice on pain or food.Hi [first name], good session today. Squats moved up to 45kg for 3x8
and your form on the last set was your best yet. Lunges were tough, so
we'll keep chipping away at those. Next up is upper body. Can you
confirm Thursday works? [your name]What you would fix: "your best yet" is a claim the AI added from "form better". Change it to "your form tightened up on the last set" if you cannot back "best yet". The recap is only as good as the notes; trainers who write one specific number and one watch-point per session get recaps that clients quote back.
Prompt 2: the weekly check-in for a client who has gone quiet
A client who has missed two sessions rarely answers "is everything OK?" with a reason. Give them an easy, no-guilt reply.
Write a check-in text to [first name], who has missed two sessions
and not replied. Under 45 words. No guilt, no pressure. Offer two
easy options: a shorter 30-minute session, or a pause until a date
they choose. One question only.Hi [first name], haven't seen you for a couple of weeks and wanted to
check in. We can do a short 30-minute session to ease back in, or pause
until you're ready. Which would suit you better? [your name]Because it offers a choice, a reply of "the short one" or "pause" costs the client nothing. A message that says "just checking you are still committed" tends to be ignored. You should still scan the output for phrases that imply fault, such as "we need to get back on track".
Prompt 3: the renewal text before a pack ends
The renewal text goes out when the client has two sessions left in a pack, not on the last day. That leaves time to choose without feeling pushed.
Write a renewal text to [first name]. They have 2 sessions left in a
10-session pack. Offer: 10 more sessions at [price] or 5 at [price].
Mention one real thing they have achieved: [achievement]. Under 60
words. One next step: reply with 10 or 5. Make it easy to say "not
now".Hi [first name], you've got two sessions left in your pack. Since we
started you've gone from [achievement], which is great progress. I can
set up another 10 sessions at [price] or 5 at [price]. Just reply 10
or 5, or "not now" and we'll chat. [your name]Rules for renewal texts: send once, then follow up once. Never say "limited spots" unless it is literally true. Never imply progress will vanish if they stop. State the price in the message so nobody has to ask. Keep the "not now" route visible, because clients who feel cornered do not renew.
Prompt 4: the follow-up when the renewal text gets no reply
Write a second message to [first name], sent 4 days after a renewal
text with no reply. Under 40 words. Softer than the first. Ask one
simple question: would they like to book their last session, or
talk about options.Hi [first name], no rush on the renewal. Shall I pencil in your last
session for later this week, and we can talk options then? [your name]If there is still no reply after this message, stop. Two messages per renewal window is the limit. A third is pestering, and the last session in the pack is the natural moment for a conversation in person.
Prompt 5: the milestone message
Milestones are honest retention. They remind the client what they have done. They work only when the milestone is real and chosen by the client, not by you.
Write a short congratulation text to [first name] for completing
their 20th session with me. Under 40 words. Mention that they set
this goal themselves: [goal in their words]. No promises about
future results.[first name], that's 20 sessions done. You said you wanted [goal in
their words] and you've turned up week after week to get there.
Proud of the effort. See you Thursday. [your name]Fix to make: "Proud of the effort" works for some trainers and sounds odd from others. Swap it for the phrase you really use. If your clients are not the sentimental kind, ask for a drier version, such as "20 sessions, nicely done".
Prompt 6: the reschedule reply
Most of a trainer's messages are replies. A reschedule request arrives, and you answer with options. The AI helps when the rules are fixed: how much notice, what counts as late, what the policy says.
A client asks to move tomorrow's 7am session. My policy: more than
24 hours' notice is free to move, under 24 hours the session is
charged unless I can fill the slot. It is 18 hours before. Write a
friendly reply under 50 words that offers Wednesday 5pm or Friday
7am and explains the policy once without sounding cold.Hi [first name], thanks for letting me know. As it's under 24 hours
I can't move it without charging unless I fill the slot, but I'll try.
If I can't, I could offer Wednesday 5pm or Friday 7am for the next
one. Let me know. [your name]The AI cannot decide whether to waive the fee; that is your call, made before you paste anything. For a long-standing client you might ignore the policy, and the reply should say so, not hide behind it. Edit the draft to reflect the decision, not the policy text.
Prompt 7: the re-engagement text after a long gap
For a lapsed client, three months or more, the message is different from a check-in. You are making a fresh offer, not chasing.
Write a text to [first name], who trained with me until [month]
and hasn't been in touch since. Under 50 words. Warm, no guilt. Offer
a free 20-minute catch-up session to talk about goals, no commitment.
One question: shall I book it?Hi [first name], it's been a few months since we trained. If you'd
like to start again, I'd be glad to do a free 20-minute catch-up to
talk about where you are and what you'd like. Shall I find a slot?
[your name]Do not mention how long they have been away in a way that sounds like a bill. "A few months" is fine; "it's been 94 days" is not. For a wider approach to lapsed customers, the method in winning back lapsed customers with AI emails applies, and the barber version shows the same idea in another trade.
Prompt 8: the group-class or small-group promotion
Write a message to my client list announcing a new small-group
session on Saturdays 9am, max 6 people, [price] per session. Under 70
words. Say it suits people who like training with others. No claims
about results. Ask people to reply "in" to hold a spot.Hi all, I'm starting a Saturday 9am small-group session. Six spots
only, [price] a session, for anyone who likes training alongside
others. Reply "in" and I'll hold a place. Happy to answer questions.
[your name]Before sending, check that "six spots only" is true and that you have consent to send promotional messages to this list. If you are in doubt about messaging consent, ask a qualified adviser; rules for marketing texts differ by customer location.
Prompt 9: the end-of-month nudge to log in or book
Write a short end-of-month text to [first name]. They have attended
[n] of [n] booked sessions this month. Under 40 words. Acknowledge
the effort if attendance was good; if lower, be neutral and offer to
book the first week of next month. One question.Hi [first name], you made 3 of 4 sessions this month, which is a good
run. Shall I book your first two sessions for next month now? [your
name]Attendance numbers come from your calendar, not from the AI. The instruction to be neutral when attendance is low matters. Models drift into encouragement that reads as sarcasm ("great effort!" for one session out of four).
Prompt 10: the review request
Write a short message to [first name] asking for a review. They have
trained with me for 6 months. Under 45 words. Tell them where to leave
it: [link]. Say honest feedback helps. No incentives, no script of what
to write.Hi [first name], if you've enjoyed training together, a short review
would really help me: [link]. Honest feedback is welcome, and it takes
two minutes. Thank you. [your name]Never tell a client what to write, and do not offer discounts in exchange for reviews unless the review platform allows it. Check the platform's own rules before you ask.
Teaching the AI your voice: a before and after
The single biggest upgrade to every prompt above is a style sample. Collect three real messages you sent clients and liked. Paste them under a heading "My style" in the standing instructions, and tell the AI to match their length, word choice and punctuation. The difference is large.
WITHOUT A STYLE SAMPLE:
Hi [first name]! Great work today! You absolutely smashed your squats!
Keep up the amazing effort and see you next time!
WITH TWO OF MY OWN MESSAGES AS A SAMPLE:
Hi [first name], solid session. Squats moved up and the last set looked
steady. Lunges next time. Thursday still good?The first version could come from any gym anywhere, and clients notice. The second is shorter and sounds like a person who watched the session. If a draft still feels too enthusiastic, add a rule: "no more than one positive adjective per message".
Timing: when each message goes out
| Message | When to send | Limit |
|---|---|---|
| Session recap | Within a few hours of the session, same day | One per session, under 70 words |
| Check-in after missed sessions | After the second missed session | One, plus one follow-up a week later |
| Renewal text | When two sessions remain in the pack | One, plus one follow-up after four days |
| Milestone | Within a day of the milestone | One, only for goals the client set |
| Re-engagement | Three months or more after the last session | One offer; no follow-up for a month |
| Review request | After a positive moment, never after a complaint | One |
This table is more useful than any single prompt, because the failure in most trainers' messaging is timing. A renewal text on the last day of a pack feels like a bill. A recap two days late feels like an afterthought.
Walking one client through a pack, with illustrative numbers
Take a client on a ten-session pack at an illustrative price of $600, so $60 a session. The trainer uses a notes app to jot a line after each session and the prompts above to turn notes into texts.
- Sessions 1 to 8. After each, a recap text drafted in about a minute from two lines of notes. Eight recaps, about 12 minutes of total work including edits.
- Between sessions 4 and 5. The client cancels once, and a rescheduling reply (prompt 6) offers two slots. Pack stays on track.
- After session 8. Two sessions left, so the renewal text goes out (prompt 3), offering ten more at $570 a pack or five at $300. The client replies "five, thanks" the same evening.
- After session 10. The trainer books the first of the next five and sends a short milestone message, since this client set a goal of finishing the pack.
The tool cost is the AI subscription the trainer already uses, and the time cost is perhaps 20 minutes across the pack. The result is one renewal that did not need a difficult conversation, which is worth far more than the minutes. These figures are an illustration, not a prediction of renewal rates.
Handling the replies you cannot draft in advance
Drafts help with outgoing messages. The replies that matter most are the ones coming back: "can I do cheaper?", "I'm injured", "I'm moving", "I'm not sure this is working". Treat each differently.
- Price questions. Draft a reply with the AI if you want, but decide the answer first. Offer a smaller pack or a pause before a discount. A discount for one client sets expectations for others.
- Injury or health mentions. Answer personally, say you will adjust sessions, and suggest they speak to a qualified professional. Do not paste the message into an AI tool.
- Doubts about results. Call or meet. A text exchange is the wrong place to discuss whether the programme is working.
- Leaving. Reply with thanks and one open door. Ask for one line of feedback if they are willing, and log it.
A short log that makes every prompt better
Keep a simple table: client initials, last session date, sessions left, last message sent, response. Four columns, one row per client. It lets you ask the AI the right question ("which of these ten clients have two sessions left?") and prevents duplicate messages. It also stops you messaging someone who said "not now" last week. Initials only, no health details; it is an admin list, not a record of their body.
Once a month, scan the log for clients with no session for 14 days and no message sent. Those rows are your check-in list. Ten minutes on that list, with prompt 2, is the cheapest retention work a trainer can do.
Retention rules that stop the messages backfiring
Good prompts do not rescue a bad rhythm. Keep to the following, and write them on a card beside your phone.
- Two messages per event. Renewal, check-in or re-engagement: one message and one follow-up. Then stop.
- Daytime only. Nothing before 8am or after 8pm unless the client usually messages you then.
- Same voice. Read each draft aloud. If you would not say it, change it.
- Specific over generic. A message that could go to any client is weaker than one with a real number from the session notes.
- The no is respected. A "not now" is recorded and honoured. Do not message the same client again for at least a month.
An illustrative case: a trainer with 30 active clients sent the same renewal message to eight of them in one week, copy and pasted from the AI. Two clients compared texts and noticed. After that she asked the AI for a different version each time using the client's own goal, and kept two lines in her own words in every message. Response rates were not measured; the point is that identical messages are visible when clients talk to each other, and in a small community they do.
Testing the prompts on your own clients
Do not trust a prompt because it worked once. Pick five clients and run the relevant prompt for each, with the real notes and numbers (leave out health information and names). For each draft, check:
- Is every number one you supplied?
- Is there any advice about pain, food, supplements or medical matters?
- Does it sound like you, or like a brochure?
- Is there exactly one next step?
- Is it under the word limit?
Any failure points to a prompt line to tighten. If the AI keeps adding encouragement you do not use, add "no praise words except those in my notes" to the standing instructions. If it keeps getting the length wrong, ask for a maximum character count instead of words.
The renewal text that slipped in medical advice
A trainer asked an AI tool for a renewal text and included, to be helpful, a line from her notes: "client's knee has been sore, going easier on squats". The draft came back with a friendly sentence about "protecting that knee" and suggested the client "keep icing it". The second half is medical advice she never meant to give, and the first half put health information into a tool she had not checked the privacy terms for. The client was fine, but the trainer deleted the text, removed the health line from her notes template, and added "never include injuries or symptoms in a prompt" to her standing instructions.
The fix is structural. Keep two note fields: one for the prompt ("squats up to 45kg, lunges tough") and one private line for anything about health that never leaves your own records. Then there is no way for a sensitive detail to slip into a draft by accident.
Checking the saving on your own week
Time yourself for one week. Note how long you spend on recaps, reminders and renewal messages by hand, then repeat with the prompts for a second week. Compare the totals and count the messages that actually went out; the second number is often the bigger gain. If you find you are editing every draft heavily, spend an extra ten minutes on the style sample and the standing instructions. A prompt that needs a full rewrite each time is not saving you anything.
When to write it yourself
Skip the AI when a client has been injured, bereaved, ill or otherwise in difficulty. Skip it when you are cancelling or changing a price and the client will be upset. Skip it for complaints. The saving from AI is largest on routine, positive messages, and smallest, even negative, on sensitive ones. A message from a human who is visibly choosing their words is part of what a trainer sells.
Rough maths for a trainer with 25 clients
Take an illustrative trainer with 25 active clients. Five session recaps a day at three minutes each is 15 minutes; with a prompt and a 45-second edit, about four minutes in total. Renewals: perhaps eight a month at five minutes each by hand, against two minutes with a prompt. The monthly saving is a couple of hours at most. That is worth having, but its real value is consistency: recaps go out every time and renewals go out before the pack runs dry, not after.
For scheduling and automatic reminders, software that handles check-ins and billing sends the messages on a timetable; these prompts supply the words. Where an automated agent should stop and hand a conversation to you is covered in AI agents and client check-ins for trainers, and the data question behind all of it is in the checklist for client health data and AI tools.
If you would like help setting up the standing instructions and a review habit that suit your business, that is what my AI implementation consultation covers; you can get in touch here.
Questions trainers ask about these prompts
Should I put client names into ChatGPT?
Leave them out. Use [first name] as a placeholder and add the name yourself after the draft. Names are not needed for the AI to write a good message, and leaving them out removes the main privacy question from the job.
Can AI tell me what a client should eat or lift?
Not through these prompts. They cover messages and admin only. Medical, injury and diet advice belongs with qualified professionals, and the prompts below tell the AI to avoid it. If a client raises a health issue, answer personally or refer them on.
How long should a renewal text be?
Under 60 words for a text, with one clear next step and a way to say no. Longer renewal details go in a follow-up message or a call, not in the first text.
Will clients know the message was written by AI?
Not if you edit it into your own voice, which takes a minute. Give the AI two or three of your own past messages as style examples and always read the draft aloud before sending.
Further reads
- Personal Trainer Progress Reports: Monthly Client Summaries With AI — Turn session notes into a monthly progress summary.
- AI for Fitness Trainers: Client Check-Ins Without Medical Advice — Check-in messages that stay clear of medical advice.
- How Personal Trainers Can Use ChatGPT Safely for Client Programmes — Use ChatGPT safely for the programmes behind the recaps.
- How Much Should a Personal Trainer Charge? Model Session Packs With AI — Set the pack prices your renewal texts will offer.
- Is Vagaro Enough for a Personal Trainer? Packs, Bookings and Vera — Track session packs so renewal texts go out on time.
- Personal Trainer Intake Forms: Build One With AI, Protect Health Data — Build the intake form that feeds good recaps.
- AI Fitness Video Maker: Turn a Class Plan Into Member Videos — A trainer's workflow from written class plan to short member videos, with the safety and music-licence checks that matter.
- Best Free AI for Personal Training: Client Programmes and When to Pay — What a personal trainer gets from four free AI plans, which client details never go in, and the time sums that show when a paid plan earns its fee.
- ChatGPT Fitness Coach Prompt: Client Programme Template for Trainers — A copy-and-paste prompt that drafts a four-week client programme, stops on red flags and leaves the final call to you.
- Personal Trainer Social Media Posts: A Month of Content With AI — A four-week plan of 20 posts for a personal trainer, caption prompts that stay inside your facts, and the no-false-claims check for results posts.
- Can a Personal Trainer Edit Testimonials With AI? What Is Allowed — What AI may and may not do to a client's testimonial: consent, result claims, light edits and a four-minute check before you post.
- AI Tools and AI Development: The Complete 2026 Guide — the AI hub, including every tutorial in the AI-for-business series.
Sources: no vendor data used; prompts are tested patterns. Check the privacy terms of whichever AI tool you use before entering any client information.