The problem: 4 hours a day lost to admin
A personal trainer with 30 active clients in Barcelona came to us with a very concrete problem: he was spending more time answering WhatsApps, confirming appointments and chasing payments than actually training his clients.
The weekly breakdown was brutal:
- Answering repetitive questions: 8h/week
- Confirming and managing appointments: 5h/week
- Sending training plans: 3h/week
- Chasing payments and issuing invoices: 4h/week
- Total: ~20 hours per week on tasks that generated no value
The goal was clear: automate everything repetitive so he could dedicate that time to acquiring more clients — or simply rest.
The solution: 4 interconnected automation workflows
Workflow 1: WhatsApp AI bot
We connected WhatsApp Business API with our automation platform and OpenAI to create an assistant that:
- Answers FAQs (schedule, pricing, services) using his own knowledge
- Classifies incoming messages by urgency
- Books appointments directly in Google Calendar when the client requests it
- Only notifies the trainer when something requires human attention
Result: 80% of messages handled automatically.
Workflow 2: Automated appointment management
When a client books an appointment (via WhatsApp, web or Calendly):
- The event is created in Google Calendar automatically
- The client receives a WhatsApp confirmation within seconds
- A reminder is sent 24 hours before the session
- If the client cancels, the slot is freed and offered to the waiting list
Workflow 3: Training plan delivery
Every Sunday at 8pm, the system:
- Checks which clients have a session that week
- Generates a personalised email with their weekly plan
- Attaches the PDF plan matching their level and goals
- Logs the send in the tracking dashboard
Workflow 4: Stripe billing and payments
After each session:
- Stripe automatically charges the client for the session
- An invoice PDF is generated
- It is sent to the client by email
- The payment is recorded in the dashboard
The results
After 6 weeks with the system live:
- Time on admin: from 20h to under 4h per week
- Client response time: from hours to under 2 minutes
- Clients managed: from 30 to 47 with the same workload
- Unpaid invoices: 0 (vs 3–5 per month previously)
The trainer was able to onboard 17 new clients without increasing his administrative burden at all.
Tech stack used
- Automation platform (self-hosted) as the central orchestrator
- WhatsApp Business API via 360dialog
- OpenAI GPT-4o for message processing
- Google Calendar API for appointment management
- Stripe for recurring payments and invoicing
- Supabase as the database layer
Does this apply to your business?
If you offer any kind of service (consulting, coaching, therapy, classes…) and you have more than 10 active clients, this type of automation makes sense.
The ROI-positive threshold is typically reached with just 2–3 additional clients you can take on thanks to the time recovered.
Book a free audit and we’ll analyse which parts of your operations to automate first.