Do you diligently check your phone’s health app? It’s fascinating to see graphs of how many calories you think you’ve burned and how your heart rate has changed.
But apart from solipsistic concerns about every aspect of ourselves, is there any evidence that using these apps improves our health?
Let’s take a look at three of the most studied healthcare app measurements: heart rate (usually measured using a smartwatch), number of steps taken per day, and amount of sleep each night.
resting heart rate
People with lower resting heart rates tend to live longer. They have a lower risk of all kinds of health conditions, including heart disease, heart failure, and even cancer. Compared to someone with a resting heart rate of 50 beats per minute, a person with a resting heart rate of 90 beats per minute has about twice the risk of premature death.
Scientifically, none of that is debatable. So should I be happy that my resting heart rate is 51 bpm according to my smartwatch and I’m sitting here writing this?
necessarily. It’s not clear whether heart rate is the cause or effect of health problems. Could resting heart rate increase if people are in poor health? Sure. Can drugs that slow people’s heart rates improve their health? Maybe. Perhaps it will go both ways at the same time.
But more importantly, the relationship between heart rate and health status is not that strong. Going from 50 bpm to 90 bpm doubles the risk of death, which is a significant increase in bpm. Significant changes in one person are worth reporting to your doctor, but routine changes like those noted by health apps are probably not a cause for concern.
Still, one of the main things people do to lower their heart rate is to exercise more, and that seems like a good idea for all sorts of reasons. This tells us:
10,000 steps
I’m a simple guy who believes in the “calories in, calories out” theory of weight gain and weight loss. In other words, if you burn more calories or take in fewer calories in the first place, you’ll lose weight. Losing weight improves all kinds of health outcomes. So encouraging people to move a little more with goals like “10,000 steps a day” seems like a good idea at first glance.
But is there a reason to use a specific number of 10,000? Healthy adults take between 4,000 and 18,000 steps a day, depending on age, occupation, and country. 10,000 is pretty arbitrary, and there’s no magic threshold above which you’ll get any health benefits.
But one of the latest large-scale studies published in March of this year found that regularly walking more than 8,000 steps a day is associated with a lower risk of a range of health problems, including cardiovascular disease (not to mention premature death). It is said to be associated with reduced risk.
But of course, just like with heart rate, the opposite is also true. Poor health may reduce the amount of walking you do. That’s why randomized trials that encourage people to walk more and measure it with pedometers and apps are useful. And in general, it shows that increasing your step count leads to improvements in your health, including (as I expected) weight loss.
But they don’t specifically support the number 10,000. One person said: Goals that represent increases over baseline values are likely to be much more important [than] Accurate target number.”
So don’t beat yourself up if you don’t get 10,000 steps every day. However, if possible, we recommend walking a few thousand steps more than usual. And if you find walking boring, have you ever heard of podcasts?
8 hours sleep
Of course, podcasts are another favorite sleep aid. Some people (like me, find this really weird) believe in the idea of voices dripping into their ears to wake them up at night. Most podcast apps also have a “sleep timer” as an option.
This is all in response to our societal quest to get more sleep. According to some super popular bestselling books, almost all of our illnesses can be traced to the fact that we don’t get eight hours of sleep.
And you know what? In this case, the actual numbers are not far off. A meta-review published in 2020 looked at 11 previous systematic reviews of research on sleep and all types of health (and mental health) outcomes and found that “7 or 8 hours of sleep per day “Time is best associated with sleep duration.” health”.
The relationship between sleep and health is an inverted U-shape. Until about 7 or 8 hours, your health will become better and better. But anything more than that may indicate that things aren’t going very well. And keep in mind that, like both cases discussed above, much of this is a correlational study. There’s not much evidence about what happens when you intervene to make people sleep longer.
One thing the meta-reviewers noted was that sleep was assessed subjectively in 96 percent of previous studies. People were reporting how much sleep they were getting without using any devices. This introduces a bias because people tend to overestimate how much sleep they actually get (newer studies done in the age of smartwatches are more reliable). In fact, just under eight hours may be a perfectly healthy amount of time.
And the final point is that everyone is different. Sleep research hasn’t yet determined what sets some people apart from those lucky enough to get less sleep than others.
So overall, the average person should aim for 8 hours. However, remember that you are not necessarily the average person.
worried well
Doctors sometimes talk about “anxious wells.” These are people who are very concerned about their health, even though they are almost perfectly healthy. For example, not eating properly or not getting enough sleep.
The downside of healthcare apps is that they make worried people worry even more. Anything that allows you to analyze your heart rate in detail, or set arbitrary goals like 10,000 steps or 8 hours of sleep for your girlfriend, is a go-to for anyone looking for something interesting.
So, as long as you’re looking at the big picture, much of what a healthcare app is monitoring is likely to lead to a rather small improvement, not something that’s life-changing, so a healthcare app is wonderful. But if it’s causing you stress, the best advice is to remove it. In this case, you will notice the effects immediately.