Client reminders: push, SMS, email or WhatsApp?
Which channel should a coach or gym use for booking reminders, missed workouts, payments, win-backs and urgent changes? A comparison table, a recommendation per message type and a simple fallback order.
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What is the best way to send client reminders: push, SMS, email or WhatsApp?
For most coaches and gyms the best default is in-app chat or push first, because it costs nothing per message and lands in the same app the client trains in. Use email for anything with details, links or receipts, and SMS, WhatsApp or Viber for the few messages that really must be seen: an overdue payment, a missed session follow-up or a same-day schedule change.
Below: a comparison table, a pick for each message type and a fallback order.
The five channels side by side
Every channel has a sender cost, a setup cost and a consent question.
| Channel | Cost to you | Setup effort | Consent | How reliably it is seen | Best for |
|---|---|---|---|---|---|
| In-app chat | Usually included in your coaching or gym software | None if clients already use your app | Part of the service; offer an opt-out for automated messages | High for active clients, low for people who stopped opening the app | Check-ins, plan updates, missed workouts, anything that may start a conversation |
| Push notification | Usually included | Client must install the app and allow notifications | The phone asks the client; they can switch it off at any time | High when enabled, zero when disabled | Short time-bound nudges: session in 2 hours, check-in due today |
| Low; depends on your email provider plan | Connect a provider or SMTP, set up sender domain records so mail does not land in spam | Service emails are expected; marketing needs opt-in and an unsubscribe link | Medium; often read later, sometimes filtered | Receipts, renewal notices, weekly summaries, anything people want to find again | |
| SMS | Paid per message by your SMS provider; varies by country | Provider account, sender number or name, country rules | Explicit opt-in for marketing in most countries; STOP must work | High; works on any phone, no app needed | Urgent changes, payment problems, clients who never open apps |
| WhatsApp / Viber | Business messaging is charged by the platform, by conversation or message type; manual sending from your phone is free | Business account and verified number; message templates for WhatsApp outside a reply window | Opt-in required; people block business numbers quickly if it feels like spam | High where the app is the default chat app in that country | Personal follow-ups, booking confirmations, reminders in markets that live in WhatsApp or Viber |
I left provider prices out on purpose. They change often and differ by country, so check your SMS, email and WhatsApp provider's pricing page before you plan a campaign to 500 members.
Which channel to use for each type of reminder
The mistake I see most often is picking one channel for everything. A booking reminder and a win-back offer are different messages with different stakes, so they deserve different channels.
Booking or session reminder
Push first, chat as the record. A reminder a few hours before the session, or the evening before for early-morning slots, is enough. For in-person coaches whose clients do not use an app, a WhatsApp or SMS the day before works better than an email they will open after the session.
Missed workout or missed check-in
In-app chat. This is a coaching message, not a notice. It should sound like you, invite a reply and sit next to the workout history. If the client is still silent two or three days later, a second message on WhatsApp or SMS is reasonable. After that, stop automating and write to them yourself. Our examples of automated check-in messages show how to phrase these without sounding like a bot.
Payment, renewal and failed charge
Email plus push or chat. Email carries the amount, the date and the payment link, and it is where people look for receipts. A short push or chat note makes sure it is not buried. If a payment is overdue after a reminder or two, move to SMS or WhatsApp, and for a gym also hand it to reception as a task.
Marketing and win-back
Email, or WhatsApp and SMS only with opt-in. Email with an unsubscribe link is the safe default. If someone explicitly agreed to hear about offers on WhatsApp, use it, but space these out: one win-back message every few weeks is plenty, and nobody should get a promotion the same day as a payment reminder.
Urgent schedule change
SMS or WhatsApp, plus push. A class cancelled an hour before start is the one case where reach matters more than cost. Send it through the channel that works without opening an app, and post it in the app too so people who check there see it. If it happens early in the morning, send it yourself rather than wait for an automation.
| Message type | First channel | Second step if needed |
|---|---|---|
| Booking or session reminder | Push | WhatsApp or SMS the day before for clients without the app |
| Missed workout or check-in | In-app chat | WhatsApp or SMS after 2-3 days, then a personal message |
| Payment or renewal | Email + push or chat | SMS or WhatsApp, then a staff task |
| Marketing or win-back | WhatsApp or SMS only with opt-in | |
| Urgent schedule change | SMS or WhatsApp + push | A phone call for private sessions |
Use a fallback order, not every channel at once
Sending the same reminder on push, email, SMS and WhatsApp at the same moment feels like being shouted at. A fallback order is calmer and cheaper:
- Send in chat or push first. It is free and it is where the client already is.
- Wait for the thing you actually want: the booking confirmed, the check-in submitted, the invoice paid.
- If it has not happened after a sensible wait, send one message through a connected channel such as WhatsApp, SMS or email.
- If there is still no reaction, a human takes over: you, a coach on your team or reception.
The key is step 2. You are not waiting to see if a message was read, you are waiting for the result. A client who paid after the push does not need the SMS.
In tools with conditions and waits this is one branch: "if the check-in is still missing after 2 days, send the WhatsApp version, otherwise do nothing".
Consent, quiet hours and frequency
Channel choice is only half of it. The other half is not annoying people:
- Quiet hours. Nothing automated late in the evening or before breakfast. A 22:00 reminder gets notifications turned off.
- A daily and weekly cap per person. Several automations can hit the same client on the same day: missed workout, check-in due, renewal. Without a cap they stack up.
- Step back when a human wrote. If you messaged the client this morning, the automatic "how is it going?" should not go out this afternoon.
- Honour STOP everywhere. On SMS, WhatsApp and Viber a STOP reply must stop automated messages, and every email needs an unsubscribe link.
- Separate marketing from service. Some clients want reminders but no offers. Let them choose.
For WhatsApp in particular there are extra rules around business numbers, templates and opt-in. We cover them in WhatsApp for gyms and personal trainers.
How this works in Trainera
In Trainera Automations, in-app chat and push work from day one with nothing to connect. Email goes through your own SMTP or email provider, SMS through your own Twilio account, Viber through your own Viber Business account, and WhatsApp through your own WhatsApp Business number connected through Meta, or as prepared messages you send yourself with one tap. Trainera adds no per-message fee; your provider's own rates apply.
The safety rules above are built in: quiet hours from 21:00 to 08:00 by default (editable, and replies to a message the person just sent go out right away), at most 2 automated messages a day and 6 a week per person from one sender by default, a 12-hour gap between marketing messages, and soft-touch steps are skipped when you or your staff wrote to the person in the last 24 hours. STOP replies are honoured in chat, WhatsApp, SMS and Viber, and people can opt out of all automated messages or of marketing only.
Push only helps if clients open the app, so it is worth reading what to send as push notifications and how often. And reminders are one part of keeping people; the bigger picture is in client retention for coaches.
A setup you can copy this week
- Session and check-in reminders: push, with a chat message as the record.
- Missed workouts: chat in your voice, one follow-up on WhatsApp or SMS, then you.
- Payments and renewals: email with the details, a push to point at it, then a staff task.
- Win-backs: email, or WhatsApp only for people who opted in.
- Urgent changes: SMS or WhatsApp plus a post in the app.
Start with chat and push, connect one extra channel only when you have a message that needs it, and keep a human at the end of every chain.
Set up reminders with quiet hours and per-person limits in Trainera Automations.
Frequently Asked Questions
What is the best way to send reminders to fitness clients?
Is SMS or WhatsApp better for gym reminders?
Do I need consent to send clients reminders by SMS or WhatsApp?
Why are my push notifications not being seen?
How many reminders is too many?
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