The best ways to measure health improvements in your app

(No, it’s not weight)

Sam Liberty
9 min readNov 13, 2023


A couple months ago I put out a story on Medium that explained that many health apps are making huge mistakes, disengaging their users by setting unrealistic goals, throwing users’ weight-loss failures in their faces, and bombarding them with patronizing “advice” in the form of scolds.

This received mixed reactions. Some saw the sense in, while others were confused. “So it’s bad to take measurements? Set goals? Give advice? Then what on earth should a digital therapy do?”

Of course, your DTx or health app needs to set goals and guide users, just don’t do it in an unrealistic or scoldy way. And as for measurement, is it important? YES.

Without measurements the user doesn’t know they are making progress, the therapy can’t prove it’s efficacy in a clinical trial, and investors don’t know whether or not your app works.

The question is: what do we measure to do all these things without discouraging our users?

Weight is easy to measure. Everyone owns a scale and understands what a pound and an ounce is. Other things that matter more (blood sugar, cholesterol, resting heart rate) are much more confusing, difficult, and even painful to collect, so far fewer apps do it.

But there are ways of splitting the difference that can be not just simple enough for any user to record, but even fun and motivating! Interested in learning what they are? Read on!

…But first a note on weight

If you already understand why weight should usually not be focused on in a health app (maybe you read my last article on this), go ahead and skip this section.

I’ll boil it down to four points.

  1. It’s very hard to permanently lose weight, so watching that number hold steady or go up is discouraging
  2. People have hangups about their weight so asking for it is alienating to some
  3. Many have disorders related to their weight, and your app risks triggering them by centering users’ weights (or god forbid gamifying it) in the experience
  4. Critically, weight is not actually a good measurement of health at all. Many others are better.

What To Actually Measure (and How)

Hopefully you’re convinced by now to look at other ways of assessing health. A recent New York Times article focuses on this in a general sense by laying out a few ways to measure overall health that are not related to weight. I will use this as a point of departure, and go into detail on what it means and how you can use these insights in your app’s design.

Heart Rate

Cardiovascular health is one of the keys to overall health and fitness. Heart Rate is the simplest measurement we have to assess it, and thankfully it’s easy to understand. How many times does your heart beat in a minute?

Luckily for us, wearables are already measuring this, so if your users are the kind that own them, this is a layup. If your users don’t own these, the job becomes a little harder, but bare with me: you can use this to your advantage.

When most people think about heart rate, they probably picture an athlete on a tread mill (or themselves at the gym) with a heart rate monitor built in to the equipment. Heart rate is an important tool for effective exercise, especially for athletes, but it is not necessary for most people to enjoy the benefits of exercise.

Instead, I recommend you focus on something called Resting Heart Rate. This is the beats per minute when you’re at rest, i.e. not exerting yourself. This is great news for users’ who might not want to exert themselves every time they want to measure their progress.

Resting Heart Rate varies from person to person, but the more fit you are, the lower it tends to be before it bottoms out at around 60 for most people. Lower than, or irregular beats, can actually indicate a problem. Importantly, as you become more fit, your resting heart rate should go down! The benefits of this are huge. And this is something users can focus on without losing any weight at all.

So what do we do if our users do not own wearable trackers?

Measure the old fashioned way. For most, finding their pulse is easy: simply press your fingers into the side of your neck under your jaw and you will feel it.

It might sound like a lot of work to get them to measure this, and of course they could make mistakes when they do it, but there is some evidence that higher friction can help users engage in some cases. These are what are sometimes called “meaningful inefficiencies.” Users who do this will actually feel more control and ownership over their own health.

The key is, making the experience fun and enjoyable.

Can you make a game out of it? Give strong feedback? Provide amazing UX and guidance? I’m sure you will find a way to make that experience one people will look forward to instead of one they dread. And if you can celebrate this event, it will increase engagement with your app, not decrease it.

If your users do have a wearable, you are in even better shape, but you should still find ways of celebrating improvements. Also, with wearables you unlock other even more powerful measurements such as Heart Rate Variability, an extremely good indicator of overall health that can be measured and improved through effort.


The one thing everyone can agree upon is that exercise is good for you, and a little exercise goes a long way. Although what we eat matters a lot — to our weight — exercise matters more: to our health.

It doesn’t especially matter what kind of exercise we do. It’s all good. Flexibility, strength training, cardio, walking. All of these things are great for our overall health. Maybe better than any other single thing we can do.

So if exercise is so good, it stands to reason, this is what we should measure.

A user can self-report their exercise, but this is tedious. Unlike heart rate which actually involves a user’s cognitive effort, logging exercise is a menial task: data entry, essentially. One of the best ways I can think of to make a hard thing even less desirable is to also make it a data entry task.

My children love to read, but hate filling out reading logs that they take home from school. I love to cook nutritious meals, but hate food logging. And so on.

The good news is, even users that do not have a wearable can track some forms of exercise via their smartphone without having to enter anything at all. Modern smart phones track steps, pace, and more. This covers cardio. Strength training and flexibility are a tad harder, though, and this still leaves the question of how much exercise to do, when, and how?

Goal Setting

The best way I know of to make this experience both enjoyable and meaningful is by setting goals. A good goal must be self-directed, measurable, achievable, and repeatable.

Let me stress the difference between achievable and repeatable. With some effort, even a person with relatively poor fitness can walk 10 miles, summit a small mountain, or swim 30 laps in a pool.

However, will this hypothetical person repeat that task every day? Doubtful.

I talk about this in some detail in my previous article. Goals should be kept modest and actually be easier than what the user thinks they can achieve, not slightly harder like most people believe. This is because success feels good, and missing a goal even once is highly likely to cause churn.

Right now, I am dealing with neck and back issues. To combat these, I do a physical therapy routine. I have this scheduled to happen right after I drop my kids off for school, and deliberately picked an easy goal: stretches, and 20 minutes on the elliptical machine. This is the bare minimum, and I usually do more. But I picked this goal even though I prefer other kinds of exercise (swimming and hiking) and would rather exercise for longer. Why? Because I know it is repeatable. So far, I have not missed it unless I’ve been sick.

Measuring Progress On Simple Goals

One question you might have is, if my users are doing the same goal every day (ex. 7,500 steps, 20 minutes of cardio) then how do you actually measure progress in that goal? It doesn’t change, you just do it… forever.

The answer is that how you feel during and after the exercise goal is just as important as how much, hard, fast, etc. you do it. I.e, it’s not just about amounts.

If a user is out of breath, sweating, and aching after a 20 minute jog, there is clearly room for improvement! Two weeks later, if they are feeling energized and ready to run another mile, then they’ve improved and should be rewarded. So find ways of asking this question. A simple thumbs up or down might be OK, but there are deeper ways to do this, too. Rate Of Perceived Exertion, or R.P.E., is measured on a scale of 1–10. I probably would not use that term with my users, but it’s a tried and true way to measure that feeling.

Lifestyle / Quality of Life Experiences

R.P.E. and daily steps are great ways of measuring fitness, but they don’t get at the reason we exercise in the first place. Sure, we want to live longer healthier lives, but we also want a good quality of life. This is represented by daily activities. Can you fold laundry, go up stairs, cook a meal, drive, and play with your children without discomfort and fatigue?

We can directly ask these questions, and this is a common way of evaluating physical therapy.

From the NYT article:

Justice Williams, the director and head coach of Fitness4AllBodies, said that one of his clients knew she had made progress because, on an airplane, she was able to lift her suitcase into the overhead compartment without any assistance.

“She was so excited that after she got off the plane and went to her hotel, she called me,” he said. “There’s independence, you know what I’m saying? ‘I was able to do this by myself without asking for assistance, and that felt good to me.’”

We can also test these periodically. There are simple tests like a six minute walk, but these are fairly challenging. They ask a lot of your user (make time to get in comfortable shoes and clothes, go someplace where you can walk for six minutes, get your phone out and start this program, make sure it’s measuring properly, and walk for six minutes while doing nothing else). Compare this to other things we ask people to do on their phones, such as send a text or watch a short video, and you can see it is a very large lift.

Thankfully there are other tests as well, such as how many times you need to touch the ground or your body to stand from a lying position, reaction time tests, and simple tests of strength and flexibility. These can be quick and discrete, but are still a lot to ask.

My recommendation is to turn them into games.

People like games for many reasons and spend hours of their lives playing them. I am a game designer and have seen first hand how games can change behavior and motivate action. For a previous healthcare client, I designed a number of these games alongside healthcare experts with the philosophy that when it comes to improving health, there are no losers.

In short, if you want to change behavior, try games. And it helps that many of these tests are already game-like. They have an objective, obstacles, and feedback. All that’s missing is play!

Your health app may have other specific indicators you want to measure, but for general health, what I’ve laid out here should be more than enough to get you started. If you have questions, don’t hesitate to reach out to me. I’m always happy to discuss these ideas, especially if it means making people healthier.

Sam Liberty is a consultant specializing in games and gamification, and working in the health tech field. He is the former Lead Game Designer at Sidekick Health. He teaches game design at Northeastern University.



Sam Liberty

Lead Game Designer at Sidekick Health. Co-Founder of Extra Ludic; Designing and teaching serious games for social change and real-world impact