Why do people always respond to depressed people, by recommending visiting a therapist or going to gym?

I had seen studies that say that training or even just daily walks can highly improve mood, but I had never heard that they fully cure depression.

The solution people are commonly offering helps then, even if it isn't a silver bullet. If a silver bullet existed that instantly and universally cured depression I'm sure people would offer that instead. People are offering the best they can to a stranger.

Despite the fact that not all people are capable of doing both.

If you go online and ask strangers, you're going to get general advice. If you have a paragraph of reasons why you can't do both, either, or a modification of the advice of exercise and therapist then I feel for you but aggressively rejecting generally helpful advice while looking for some other solution is putting the responsibility on random strangers to come up with something.

I'll add that while some people may not be able to do some of the common advice, I privately suspect that at least a healthy percent of the time that resistance to the advice isn't coming from inability to do it, or in the case of the exercise part to follow the spirit of the advice by being more active. If you truly have a chemical imbalance, a therapist is the person who can help and is qualified to talk about drug solutions.

Short of telling you to see that therapist to get actual professional help, and doing exercise which while it might only a partial solution is something that you can do right away, what exactly do you want of random people?

In short: those are pretty much the two only solutions.

Of course, there are different types of depression and they can all be cured in different ways. For some of them there's no cure at the moment.

Matter of fact I had seen a study that suggest a very high percentage of people are drug treatment resistant (meaning that there depression would not get better with any prescribed drugs).

Therapist =/= drugs. First of all, a therapist cannot prescribe you anything. That's the job of psychiatrists. Both a therapist and a psychiatrist may recommend drugs for depression if they deem it appropriate, but it's by bo means the default or the go-to option (or at least it shouldn't be). Sometimes depression is a natural response to events like death of loved ones and drugs do nothing to cure it.

I had seen studies that say that training or even just daily walks can highly improve mood, but I had never heard that they fully cure depression.

Both of those things are commonly recommended by regular people as well as therapists, because they're known to be effective, and more importantly - they are completely free. For 99% of people, absolutely nothing is stopping them from doing a few pushups or walking to a park. The cost/benefit ratio here is insane. As for 'fully curing depression' - that would highly depend on the type of depression. Also, keep in mind depression is rarely cured with just one thing.

To summarize: people recommend a therapist, because a therapist is usually the best option for any mental problems, though it may not be cheap. While exercising, or just walking and interacting with nature, are basically free and always help, but may not produce noticeable results.

People recommend exercise and went to therapy because those are found helpful in manage the mood and thus manage their depression. Depression isn't like a disease, it cannot be cure. The last time people "curing" depression is by shoving a stick into their eye and mush up their brain so they won't feel depressed anymore.

Let's take those in reverse order:

Why do people always respond to depressed people by recommending ... going to gym?

You basically answered this one yourself:

I had seen studies that say that training or even just daily walks can highly improve mood, but I had never heard that they fully cure depression.

There is no permanent cure for depression. The best you can do is treat it. Getting out of the house for a walk, or to a gym, or just outside, seems to be a simple way to take the worst of the edge off for many people. But it's not a cure, which leads into the other part.

recommending visiting a therapist

There isn't a universal one-size-fits-all treatment. A therapist can help find what works for each individual. Sometimes that's changing destructive habits, or getting more exercise, or yes, pharmaceuticals (even then, there are lots of different types that work for some people and not others). Getting the best treatment often starts with professional help.

Untreated depression can be fatal. If there are physical limitations that prevent someone from being more active, and financial (or other) constraints that prevent medical care, there are support groups for depression and other ailments around the US (and I assume elsewhere): https://adaa.org/find-help/support/support-groups

What else is one supposed to say?

There is no magic code to just make depression stop.

To me, depression has always been like Bilbo in Mirkwood. He's at the top of the trees, looking around, but all he can see is trees. He doesn't realise that they're in a valley, so there's nothing but trees all of the way to the horizon. There is no end in sight. There's no point in going on: he knows that they can't go on much further, so why bother even trying. They might as well give up. But we know, from outside looking in, that he's just got to make it to the top of the next valley. If he checks again once he reaches the top then he will be able to see all the way to the Lonely Mountain and that the trees end soon and give way to the lake... He's almost through the darkest part.

So back to your question...

Making an appointment to see a therapist gives you a goal. You've made a commitment to be at a specific place at a specific time. That is often enough to get you up the next valley to see a way forward. The therapy itself can also be quite beneficial, but I've always seen the making and keeping of the appointment as a fundamental motivator for my own will when I'm deeply depressed. It's hilarious to me that I will consider ending it all, despite the effect I know it will have on my family and friends, but that I would postpone suicide to keep me from the embarrassment of missing an appointment. The depressed brain is completely irrational.

Exercise requires getting up, getting outside, going to the gym, going to the park, being around people... The exercise itself is beneficial with the endorphins and the elevated heart rate and the requirement for replenishment (eating food), but again, for me it has always been just getting out of my room and going somewhere. Just get to the front door... Right, you're here now! Might as well go for a walk. Just gotta hang on long enough to get to the top of the next valley.

I recommend exercise and therapy because it forces people to choose between the "permanent solution to the temporary problem" and the possibility of hope. 99.9% of the time, people will choose hope.

I also recommend them because they both work for me. There's no cure: you've just gotta hold on long enough to see the lonely mountain.

In my mind it's because starting training to take care of your physical health is one of the first steps toward training your brain to take care of yourself as a whole.

It's also a lot easier to feel better about your existence if you have the physical ability to do get up and spend it doing something that gives you joy, like going for a longer walk than usual because the weather hits right

There's also potential link to how we as a species have survived- we had to keep moving to stay alive, so our brains throw a wobbly if we don't.

It feels pretty weird to me that people are almost programmed to recommend Therapy or Gym as the ultimate solutions.

Depression is too vague to recommend anything. And then, a lot of people will call depression them just feeling depressed... it's complicated.

I'm not much into therapist myself, but physical activity is the one thing that allowed me to get over a decade+ long depression that almost got me killed. More specifically, daily walks.

So, yeah, if I'm discussing potential solutions with someone and I see they are not much into gym already, I will suggest they give it a shot.

Despite the fact that not all people are capable of doing both.

Sure but also don't forget 'physical activity' doesn't mean running a marathon or lifting weight. It means using one's body as much as this body allows.

When I started walking, I was barely able to walk at all. Not exaggerating, It would take me hours if not days to rest from the effort (and the pain) of getting the mail at our door. It was even worse to go buy a fresh baguette (yep, I'm French ;) at the bakery at the corner of our street. For that I would spend a lot of time preparing for this huge effort and then would I would spend the rest of the day lying down, resting, exhausted. There are worse situations than mine, obviously, but you get the idea: I was in a real bad shape. Nowadays, a few years later? I walk miles every single day. And those days when I can't walk? I feel like an absolute shit.

And it all started by deciding to walk a few more steps. Not much, really.

I'm still not an athlete and I'm still chronically ill (no cure available) but I'm also in such a better physical condition it's night and day. Even the specialists that are taking care my medical issues where floored to see the change, back then. Two of them even asked me to start talking to some patients so I could encourage them to endure the least... pleasant parts of our condition, by doing some physical activities.

As others have stated, it's general advice. I think that it is worth stating anyway because there is still stigma around mental health conditions and treatments.

As for curing depression, it really depends on the type and cause of depression. Some people have differences in their brains that cause chemical imbalances that need medication and therapy to address. Some people come down with the mental health equivalent of the flu and need support to get through it. A mental health professional like a therapist or psychiatrist is trained to diagnose and formulate a treatment plan based upon what is observed.

Depression can be fatal and I've known too many people who've succumbed to it. So, I will always recommend therapy to anyone going through depression, if they can afford it - sometimes sliding scales are available.

Your premise is wrong. People recommend all kinds of things, including those two. But you didn't tell us the backstory. Maybe you're trying to suggest that many people have told these things to you, and if so, we would want to know the context. It's quite possible that you've described your own situation in a way where those two ideas are obvious potential steps to try.

I'm also unclear what you mean about people not being capable of therapy. They might not be able to afford it, but that's not a question of their capacity. Certainly it's true that various types of therapy can be more or less effective for various people depending on a ton of factors. But it is peculiar to rule out therapy as something that's totally impossible without any explanation of how or why.

Those are the only suggestions non-therapists are qualified to offer.