HN Reader

> The author Daniel Lieberman has put it well: Exercise is healthy and rewarding even though it’s something we never evolved to do.

We have ostensibly spent much of our evolutionary budget on the ability to run ~indefinitely no matter what. Compared to virtually any other animal, we can vastly outperform them in the most arduous environments. Our bodies are mechanically optimized for running at every level. We have connective tissue that stores and releases energy. Our bodies can reject on the order of 1kW+ of heat steady-state through the magic of evaporative cooling.

The evidence for exercise reducing all-cause mortality is more nuanced than many assume. It's crucial to distinguish between findings from RCTs (Randomized Controlled Trials) and observational studies.

A meta-analysis of RCTs with ~50,000 participants concluded that exercise did not reduce all-cause mortality or incident CVD in older adults or people with chronic conditions [1].

However, for specific high-risk groups, the causal evidence from RCTs is strong. A separate meta-analysis found that for cancer patients and survivors, exercise led to [2]:

- A 24% reduction in mortality risk

- A 48% reduction in recurrence risk

The commonly cited large benefits (e.g., 40% lower mortality) come from observational studies [3]. These are very susceptible to the "healthy user bias" or reverse causation—people who are healthy enough to exercise are already at a lower risk of dying. This makes it difficult to prove the exercise caused the benefit.

So, while exercise is strongly associated with lower mortality, the direct causal evidence for the general population isn't as definitive as it is for specific subgroups like cancer survivors.

[1] https://scholar.google.com/scholar?cluster=10512580439138189...

[2] https://pmc.ncbi.nlm.nih.gov/articles/PMC7273753/

[3] https://www.bmj.com/content/370/bmj.m2031

When I got laid off from my first job, I used the extra time to start going to the gym. Years later the habit has still stuck, and I actually think I was so incredibly lucky to get laid off. Working out has been such a massive improvement in all areas of life. Health problems went away, mental health got better, sleep quality got better, it truly is a miracle drug. It’s a shame that the habit is hard to form.

I find it interesting that the article is about exercise and the title picture is yoga. In fact near the top

> To a best approximation, aerobic fitness and weight-training seem to increase our metabolism, improve mitochondrial function, fortify our immune system, reduce inflammation, improve tissue-specific adaptations, and protect against disease.

Yoga is neither aerobic fitness nor weight training

note: I do yoga probably about twice a month (should do more) so I'm not dissing yoga. I'm only noting that the picture of yoga seems to have nothing to do with the article.

Exercise "simulate the arduous tasks that were once necessary to make it through a life" makes sense, as most of our ancestors were blue-collar workers and farmers. I try to integrate more physical activity in my life, which seemed like labor before, but now feels like life-saving activity. For example, I am intentionally trying to fix/diy things with my house like painting my garage, mowing my lawn instead of hiring someone else to do it, and even learning woodworking and gardening. Even in the heat of the summer, I feel more invigorated working outdoor whenever I can, and helps offset the sluggishness I feel after a day of sitting, coding, and staring at the monitors at work.

It's difficult to overstate how much better my life has become after starting tirzepatide, consequently losing weight, and steadily increasing exercise as I've gotten lighter. If I were the richest guy in the world, I'd negotiate with Eli Lilly to make tirzepatide (or maybe the forthcoming orforglipron) basically free for anyone who wants it.

If you ever struggle to exercise consider: for thousands of years humans needed to walk and hunt and cook and run from predators just to survive. It’s sedentary lifestyles that are the anomaly.

Not exercising is a miracle NOT drug! Exercise is what your body is engineered for by nature and thousands of years of evolution. So exercising is the more normal thing, not sitting around :)

Get out there and have fun with it! Even walking you’ll get to see the sky, sunset, sunrise, and all the big houses in your neighborhood.

> Exercise is healthy and rewarding even though it’s something we never evolved to do.

OTOH we have billions or more mechanisms (basically all of them) that assume that we exercise regularly, at least when we are healthy.

for those who are biochemically inclined:

Myokines aka exerkines

I hate exercise. The only thing I hate more is not exercising.

> That I was born in the capital of the world’s richest country is one of the greatest strokes of luck in my life—a pure accident of timing and gametes. There is no way to pay back this good fortune, and wallowing in guilt over it would do nothing, either.

Why in the world does the author have to feel so bad about beibg lucky in some way? How does luck deserve the feeling of guilt? This has to be as unhealthy as exercise is healthy.

Grateful, yes, appreciative, absolutely, motivated to do good, of course. Having to pay "back" (to whom?), feeling guilty? Absurd and corrosive

I can directly tie my mood to how much exercise I’ve had in a given week. It’s also easy, given how busy life feels, to let the proverbial frog boil in water when it comes to this.

My partner often comments when I’ve been a little grumpier than usual by saying, “you should go on a bike ride.”

It really works wonders on the soul (and the more physical heart and lungs) getting out for a spin in the fresh air.

Walking is exercise. Never forget that.

Consistency over sporadic herculean efforts always wins out.

For a long time I tried to start an exercise habit, but it didn't stick. I could jog 15 minutes every day for a month and instantly be sick of it a few days after.

I was only able to gain an exercise habit by addressing my mood and anxiety first. First, with my mental improvements I became actively motivated to exercise and didn't hate it anymore. I kept at it for several weeks, only stopping every so often due to fatigue. Eventually I did earn the habit of exercise. This wasn't intuitive to me, but the typical causality was backwards. Exercise was not what directly made me healthier, but being healthier (mentally) from the start allowed me to initiate and keep exercising, from which I earned even more health benefits.

A mental deficit in being able to form habits is arguably even worse than a lack of exercise, since you would try to apply the "exercise cure" advice and just burn out after a while like I did. It's not like you didn't exercise, but you could not internalize what all those people typically say must be the case if you just exercise a lot.

Even as my mood fluctuates I am now able to still go for a jog once in a while. These days I understand that if I had started off exercising in a state of low mood, I would have no chance of making it stick. The habit carried over from when I persisted at it in my limited window of improved mood.

The best way to make a happy, healthy person into an unhappy, unhealthy person is to keep them lonely and keep them still. It should come as no surprise that the inverse also tends to hold true.

On a tangent, I think that's part of why volunteering can be so rewarding.

This article feels like a bait-and-switch. Why isn't it two articles - one on the benefits of exercise and one on US foreign aid policy?

At a minimum, I don't feel the HN post title properly reflects the full contents of the article.

> This is a staggering return on moral investment.

What exactly is moral investment and why should government be in the business of making moral investments, especially for foreign countries?

GLP-1 is a rare opportunity for our overweight nation to "get back on the treadmill" in both a literal and figurative way.

If you have been sedentary for a long time and are overweight, you obviously have too much weight for your muscular strength and connective tissues, which have concurrently atrophied with inactivity, in addition to reduced neuro-biomechanic maps in your brain since you haven't used the circuitry.

This all adds up to a high initial injury risk in starting exercise even if you have the mentally focus.

But GLP-1, if it is the miracle it purports, should be able to drop overweight people, even if it is temporarily, to the point where you can being exercise much more safely, and/or with more intensity and duration to get more benefits sooner.

On a macro level a universal health care system that is cheap and effective is really a generation or two away with heavily incentivized exercise, and not without precedent, if I am to understand what Iceland did.

We will live longer, live far better, feel better, look better, be happier, more connected, less anxious, more adventurous, smarter, more productive. These aren't 1-2% improvements at macro levels. 10% improvements, which in pharma land are considered exceptionally effective drugs, and a minimum, and 30-50% miracle drug levels of outcomes are on the table.

But our medical establishment is either drugs or surgery. The extent of insurance company inducements are "silver sneakers".

The perverse accounting involved in extreme obesity may demand a national level program of "Biggest Loser" (although, not to that insanity) for financial inducements to get people to lose weight, because the loss of "caring" for the obese (FORTY PERCENT of Americans are obese and it keeps getting worse each decade).

If you exercise a lot, be sure to fuel your workouts. Eat a healthy calories surplus so your body doesn’t go into panic mode and sacrifice muscle and bone tissue.

I’m in my 40s and have exercised my whole life. But still did intermittent fasting (skipped breakfast). I’m a standard deviation below average bone density and have lost some cartilage in my knee from underfueled long runs (I was diagnosed with RED-S). Now I work with a sports nutritionist, and do a mix of strength, running, cycling with good rest days.

I’ve learned I’d rather have a bit of a belly now but very strong than underfueled and lost muscle/bone mass

I go for a decent walk most days and it doesn't require effort or get boring. It goes well with listening to headphones and relaxing the eyes on the horizon plus seeing a bit of nature and humanity in action.

This does me a lot of good however the only upper body exercise I get is playing the piano! I can't see myself joining a gym or doing press-ups reliably in the long-term. I need to find a suitable hobby which has upper body + other benefits while being fun/interesting and low-risk. Carrying logs has helped but we have enough firewood now.

Maybe not a drug. But if the improvements in health come from bio chemical signals, it should be possible to activate those signals without engaging in exercise. Eventually?

>Like someone already said: what if you get an injury going to hard at it?

There's no need to go hard, even steady walking for 20 minutes a day is healthy. And recent studies show that you don't need to jog or run, walking is almost as efficient and less stressful for your joints.

One of the best ways to exercise as long as you aren't a brain in a jar is to use an indoor rowing machine. Rowing will engage about 80% of your muscles.

I tried to outrun my depression but then I became too depressed to run. It's so frustrating to feel that exercise doesn't give me the boost it used to.

Until you injure something particularly nasty, like a joint, tendon, muscle tear, etc...