Back in August, I discussed a long New Yorker article that looked at the world of wealthy anti-aging activists, also known as biohackers, especially one Peter Diamandis, who go to extraordinary lengths to try and increase their lifespans and even seek immortality. Since they are so rich, they can afford to spend vast sums of money on these efforts and can propagate their ideas in the media.

But ordinary people who try to follow their practices can find themselves in difficulties, as can be seen from this letter to the editor that appeared the following month in which the correspondent Matigan King described her own experience.

I enjoyed Tad Friend’s witty and entertaining piece about the fascinating world of anti-aging (“Live Long and Prosper,” August 11th). I’m particularly grateful to Friend for pointing out that some of the trendy life-style interventions advocated by health influencers, such as intermittent fasting, affect women differently than they do men.

I am not a biohacker, but, like the people Friend writes about, I am very particular about my diet and exercise. As a twenty-five-year-old woman, however, I’ve found that heeding the advice of folks akin to Peter Diamandis, the wealthy entrepreneur whose quest for longevity Friend focusses on in his piece, has not always been in my best interests. For years, I devoured books and podcasts about health and exercise, and stringently followed their prescriptions. I fasted. I trained. I “perfected” my diet. In my mind, I was the epitome of health—but in reality I was skeletal, constantly fatigued, and weak. Eventually, I even lost my period.

Today, I’m less inclined to feel that I should adopt habits that have been shown to induce positive results pretty much only in men. I’ve made changes to my training routine and diet, and, since then, I’ve felt stronger, sharper, and more nourished. I only wish I had known earlier that emulating the routines of people like Diamandis was not the right thing for my body.

True, this is just one case, but King’s words illustrate how, if you are already in general good health, then pushing your body to the extremes of exercise, diet, and supplements in order to get the promised increases in lifespan may not be such a good idea, especially if you are a woman, since many of the major proponents of these extreme biohacking methods seem to be men. The increase in lifespan, even if it occurs, may be modest while the cost in terms of time and money and being miserable can be great.

Part of the problem is that we now have wearable devices that constantly monitor and quantify so many things: how often we stand, how many steps we take, how many calories we are using, our heart and breathing rates, our body temperature, our blood oxygen, how much sleep we are getting each night and how much in each category (REM, core, and deep), and more, and reports those numbers to us. Before we had them, we had only our bodies to give us indications. If we woke up feeling refreshed, we felt that we had had a good night’s sleep. When we got tired and our bodies started to ache, we felt that we needed to stop and have some rest.

But now people set targets in terms of those measurable metrics and push themselves to meet them even when their bodies are screaming to them to stop or at least take it easier, like King seemed to have done. Even I fell into this trap. When I first got my Apple Watch, I was fascinated by the novelty presented by all this data and so set daily targets for steps, standing, sleep, and calories used, and so would, towards the end of the day, push myself to meet those targets if I was falling short. If I ended up being just a little short of the daily target, I would feel that I had somehow failed. But after a while I told myself, to hell with it. I am paying so much attention to monitoring this data that I am not doing things that I enjoy, and even when I am doing enjoyable things, the pleasure is diminished by guilt, that I should be doing something better for my body. I now try to live as actively as I can consistent with life being enjoyable and not a chore.

It is similar to the ‘cold plunge fallacy’ I wrote about where people are willing to suffer through all manner of harsh experiences in the belief that it is good for them, even if the evidence is scant. It also ignores the mental health aspect. The unpleasantness involved in the anticipation of having to do it, and the unpleasantness of the activity itself, may well outweigh the benefits that purportedly accrue.

As neuroscientist Rachel Barr said to Jonny Thomson:

“The things that you do for your mental health should be aligned with what your brain needs and your natural rhythms. And they should, in most cases, feel quite good.

There’s something I’ve noticed, and I’ve been calling it the cold-plunge fallacy. I know that there are some people who enjoy cold baths and that kind of stuff, and so great, go ahead and enjoy it. But for the rest of us mere mortals, the idea of stepping into an ice bath for 10 minutes a day is awful. And the amount of self-persuasion that goes into convincing yourself to do something like that might be a problem. Yes, cold plunging is evidence-based, but it might be such a small yield that you get out of it, and you hate it.

I have to wonder if that constant self-persuasion and hatred of the task doesn’t then outweigh the small, tiny benefit that you’d get from it.”

The point Barr is making is not that “cold plunging is bad.” In fact, she recognizes that it’s likely beneficial for some people. But others will hate the prospect so much that it outweighs the benefits. We shouldn’t ignore the fact that, for some people, the anxious and resentful preparation for a cold plunge is more awful than for others.

I am not saying that people should become total couch potatoes simply because it feels good. Moderation in everything is a good goal because it prevents people from going to extremes. It is the total experience, mental and physical, that should be taken into account when planning on doing something. Some people are willing to ignore the former for the sake of the latter but that may not work for everyone.