In November 2017, when I turned 49, I began a series of fitness and nutrition posts with the hashtag #PushTo50.

Bryan, an old friend from high school, saw my posts and decided to do his own push to 50. He didn’t ask me to train him. Mostly he was just looking for some tips to get started.

This felt like an opportunity. I’d never trained anyone online before, but not because I’m too old to embrace that whole Internet thing. I own a smartphone and know what all the buttons do.

It’s because I’ve been training clients in person for a quarter-century, and for the past 15 years have built up a loyal clientele (including a few celebrities) at my gym, Push Private Fitness. I simply wasn’t sure if I could replicate what I do online.

So I said to Bryan, “I’ve been thinking about doing this online. I don’t have it figured out, I don’t know if I can deliver, but if you’re willing to be my guinea pig, I’ll train you for free.”

We started in January 2018. In four months, he went from 220 to 189 pounds, and he’s maintained that weight loss since then. It changed his life. He’s a schoolteacher, and if you compare pictures of him from a previous school year, you can see how unhappy he was then, and how different he is now.

When Bryan’s brother-in-law saw the results he was getting, he reached out to me. Jared weighed 309 pounds and had a cancer scare the year before. He was much more intimidated by the process, but was willing to try. After working together for four months, he’s down to 269.

Now I’m working with their wives.

If I was freaked out about failing to deliver with online clients, I got my answer pretty quickly.

That’s how the snowball got rolling.

READ ALSO: How to Get Started as an Online Personal Trainer

In less than a year, I’ve gone from “can I deliver results?” to “how big an online business can I handle?” And I still don’t know. I love the idea of having success with people 2,000 miles away. That’s intoxicating, in a way. But it still takes time from my brick-and-mortar business. The open question is how much I can spare.

On the other hand, I’m on the cusp of turning 50, and I’ve spent half my life training clients in person. I may decide in a year or five years that I don’t want to be in the gym all day (even when it's my own gym).

My current total of 10 online clients seems doable. But I don’t know what happens if that becomes 15 or 20 or 30. Can I give those clients the level of service I’ve been giving the beta testers, and still give my in-person clients what they’ve come to expect? If I can’t do it well, I won’t do it at all.

There’s only one way to find out, and that’s by building it slowly and organically, the same way I built my offline business.

But while I’m figuring that out, I want to share a few things I’ve learned already about training clients online.

Your words are more important than ever 

Online training isn’t the only trend I’ve mostly ignored. I also avoid small-group and semi-private training.

When you only do one-on-one training, you understand you’re delivering a very personal product—not just the programming, but also the encouragement and support. So you can understand why I was scared by the thought of digital-only communication.

The biggest surprise for me is how easy it’s been to communicate via text and email. My clients and I quickly developed our own shorthand, emojis included, that works for us.

READ ALSO: Three Coaching Reasons Your Client Ignores your Advice (and How to Fix It)

You have to decide how accessible you want to be 

Most of my online clients are people I knew growing up. We text each other quite a bit, and I’ve never worried about them abusing their access to me.

But here’s the problem: I don’t want to give my cell number to new clients, people I only know from brief online interactions. I can’t imagine getting texts at all hours, from all time zones.

So, like every online trainer, I’ll have to establish parameters. At one extreme, some friends who’re online-only coaches have rigid policies: This is my window of communication, this is when I answer emails, take it or leave it.

I don’t think I’d have success with such infrequent communication. My brief experience with online training tells me how much it helps people to know I’m paying attention every single day. If I see something good in a weekly weigh-in, I’m not going to wait until a set time to give them a pat on the back. Even a thumbs-up emoji can mean a lot to them.

Strive for precision, but accept less control

If I’ve got somebody in person two or three times a week, I’m in complete control of everything they do, every rep, making sure things are perfect. Online, I have to be okay with clients learning technique by watching videos. I have to accept that I can’t ensure perfect form on every rep, or manage their progress from set to set, workout to workout. As long as they’re achieving the overarching goal of progressive resistance, all is well.

Learn to diagnose from a distance

An experienced trainer understands that results aren’t always automatic. I know how to troubleshoot my in-person clients’ programs, but figuring it out from a distance is a new challenge.

For example, I have my weight-loss clients weigh and measure food and track it with MyFitnessPal. But what do I do when the numbers show a calorie deficit and the scale says there isn’t?

It’s easy enough to suspect they aren’t recording everything they eat. In person, I can have that conversation in a way that shows I’m empathetic and not judging them. I’m still figuring out how to have that conversation online.

My goal is to bring the encouragement and positivity but still get the point across that they maybe aren’t doing everything right. I’ll say, “Look, there’s no wrong answer. Just tell me the truth. I won’t be upset. To me it’s all data—this is what you did, this is the result. Are you cool with that result? If you are, no problem. If you aren’t, then we need to figure it out.”

READ ALSO: Your Client Stopped Getting Good Results. Now What?

You can’t shake someone’s hand online

For trainers just starting out, I recommend getting really good at in-person training before going online. Yeah, I know that sounds like an old guy clinging to the old ways. I understand that many of you reading this are digital natives who don’t remember life without the Internet or smartphones. If your goal is to build an online business, what’s the point of training clients face to face?

Take it from the guy who’s been doing this since the first Clinton administration:

Working with non-virtual humans, even if it’s just for a couple of years, will make you a lot more successful when you switch to online training.

One reason: You’ll have a better feel for people, with sharper communication skills. I know what to say to my online clients because I’ve been saying the same things in person for so long.

Another reason: A lot of your potential clients will be older. They’ll have more questions, and they won’t want to wait until your communication window opens a week from now. You’ll need to be flexible if you want their business.

Which brings me back to the question I asked myself for years before I trained a single person online: Can I offer someone the same service I give my in-person clients?

I can see the attraction of offering a cookie-cutter service online, with more clients and minimal interaction. But if that’s your goal, maybe personal training isn’t the right profession for you.