Client records: what data to ask for and what to leave out
A good client record for a personal trainer holds what you need to work with that person and little else: how to contact them, what they want to achieve, when they can train and what you record together as you go. Every extra piece of data is something you will have to store carefully, keep up to date and, if they ask, hand over or delete. The question that decides each field is simple: am I going to use it?
What data to ask for
To start working with a client, four blocks of information are enough:
| Block | What it includes | What you use it for |
|---|---|---|
| Contact | Name, email and phone | Giving them access, notifying them and talking to them |
| Goal and level | What they want to achieve and where they start from | Choosing the plan and seeing whether they progress |
| Availability | Which days and at what times they can train | Organising sessions and the diary |
| What you record together | Sessions, measurements or check-ins, if you use them | Following their progress |
The last block is not requested on day one: it fills up with what you do together. And within it, too, you choose. If you are not going to use measurements, do not take them; if you are, decide beforehand which ones and how often, and tell them.
For each field in your record, try writing next to it what you use it for. If you cannot find a specific answer, you do not need that field.
What data to leave out
Data requested “just in case” is unnecessary. Some examples:
- Identity or home address details that you do not use for anything specific.
- Copies of documents sent “so that you have them” which you are not going to consult.
- Photos without separate permission, even if they send them to you by message.
- Information about other people: their partner, their family or their colleagues.
- Personal opinions about the client written in the notes.
What is not in the record cannot be lost, leaked or forwarded by mistake. And it saves you work when a client asks to see their data or have it deleted.
The rule: only what is necessary
Article 5.1(c) of Regulation (EU) 2016/679 (GDPR, known in Spain as the RGPD) says that personal data shall be “adequate, relevant and limited to what is necessary in relation to the purposes for which they are processed”, and it calls that principle “data minimisation”.
The same article, in paragraph 1(d), adds that data shall be “accurate and, where necessary, kept up to date”.
What is “necessary” in your case depends on your service: you do not need the same for an online plan as for training someone in a gym. If in doubt, consult a data protection professional; we summarise the essentials of the rules for your business in data protection for personal trainers.
Health data – separate and with their permission
Part of what ends up in a client's record may be information about their health. The GDPR defines “data concerning health” as “personal data related to the physical or mental health of a natural person, including the provision of health care services, which reveal information about his or her health status”.
Its Article 9.1 prohibits processing, among other categories, “data concerning health”, and 9.2(a) lifts that prohibition, among other cases, when “the data subject has given explicit consent to the processing of those personal data for one or more specified purposes”.
Which data in your record falls within that definition depends on what you collect and why. If you rely on their consent, in practice it is advisable to:
- Ask for it before recording any health data, explaining what you are going to use it for.
- Keep a record of when they gave it.
- Keep that data only where you work with it, not in chats or loose sheets.
- Treat body photos separately, with their own consent, as we explain in progress photos and consent.
Write as if they were going to read it
The notes in the record are useful: what they told you in the first session, what they find comfortable, what they prefer to avoid. But those notes are their data, and your client may ask to see them. Article 15.3 of the GDPR says that “The controller shall provide a copy of the personal data undergoing processing”.
So, two practical rules for notes:
- Facts, not judgements. “Prefers to train in the morning” works; an opinion about their character does not.
- Nothing you would not say to their face. If they ask for a copy of their data, the note will be in it.
And keep the record up to date: if their goal, phone number or availability changes, change it in the record too, and if a piece of data is no longer useful to you, remove it.
How Entrenify handles it
In Entrenify, each client's record brings together what you need to work with them:
- Record data – name, email, phone, sex, date of birth, height, goal, level and target weight. Only the name is mandatory, and the email is only essential if you are going to invite them to their app.
- Measurements: weight and circumferences (waist, hip, chest, arm, leg) and body-fat percentage, which the client or the trainer can record.
- Health consent: the client gives it from their app and the date is recorded, which you see in their record. Without it their measurements cannot be recorded, including those you take yourself, and you cannot accept on their behalf.
- Photos: they carry a consent separate from that for health data.
- Documents: what you upload to their record is not shared with the client until you decide to share it.
- Notes: the note you write in their record is part of the copy of their data.
- Copy and deletion: from their record you can download a copy of their data and, if they ask, delete it; the client can also download their copy from their app.
What it does not do: it does not decide for you what data to ask for, nor does it draft the information you give your clients about their data. What to do with the record when a client leaves is covered in a client leaving and their data, and the rest of the product is on the Entrenify home page (in Spanish).
Sources consulted
Checked on 11 October 2026. We link to the original source so that you can consult the current text.
Frequently asked questions
Can I create a client's record without their email?
Yes. In Entrenify only the name is mandatory; the email is only essential if you are going to invite them to their app, and you can give them access later.
Can I record their measurements before they give their consent?
In Entrenify, no: without their consent for health data their measurements cannot be recorded, including those you take yourself. They give it from their app and you cannot accept on their behalf.
Does my client see the notes I write in their record?
They do not appear in their app, but they are part of the copy of their data that they can download. That is why it is best to write facts and nothing you would not say to their face.
How long do I keep the record of a client who no longer trains with me?
It depends on what you need it for. The principle is to keep data for no longer than is necessary for the purposes of the processing; we expand on this in the article on a client leaving.