It's woo. I've been a licensed massage therapist specializing in neuromuscular deep tissue and it burns my biscuits when I see someone perform reiki and then proclaim some BS about I feel your lower intestines are blocked simply by hovering their hands over their body. Everyone's lower intestines are blocked because they have to take a shit. I use this as an example because I heard it yesterday from a woo master. No offense.

Well, humans can sense heat energy and use it to cook. There’s many more examples like that, I’m not going to try to list.

Pseudoscience

Nope. All the nope. I run away when folks start waving that around.

I wrote the original question and seeing all the answers made me think of something else. A long time ago I was asked to be the Christmas angel in the town parade. I don't believe in angels but I do like fun stuff and I had a huge pair of archangel wings and a gorgeous red and gold angel outfit and even a halo. So it was a fun dress up occasion for me but what happened during the parade was that people actually believed I was an angel and they wanted to tell me their troubles and they wanted to touch me or hold my hand. It was an amazingly poignant lesson for me to understand how desperately some people want to believe in something.

No offense but pure quackery

One of my best friends is a Reiki practitioner. She is also a certified Naturopathic healer and secular minister. The couple have an amazing labyrinth and are into nature big time. Reiki works for some people (like my late partner) but I don't feel a thing. To me it's all about one's mind. I do believe one's mind can do fantastic things (ever hear of stigmata's).

Do you believe that we humans can sense energy and potentially use it?
NO, there is no scientific evidence of this at all.
What there is , is a lot of cognitive bias on both the praticioner and the patient, this can create a mental feedback loop between them reinforcing the bias, so both think and/or "feel". In other words its a mental state of mind,

No energy can be measured in any way, no energy we can detect, or that we understand in any way at all.

SO, your question actually is
Do you believe that we humans can sense magical, supernatual, undetectable, energy and potentially use it?

No, I dont. I do think people can be talked into that though, because we are emotional beings and the appeal is emotive in nature. People "Feel" it is true.
But feelings are not a good source of evidence of a truth, they are brain effects we can and do cause ourselves to feel.

There is a lot of things I don't know.... don't we use like less than 10% of our brain capacity? Humans are still in their infancy so I won't get to see it but this specie potential is beyond our actual comprehension. Nature at work!!!

Of course. We are made of matter, which is just slowed-down energy.

I looked into it a few years back. It seemed like bunk pseudoscience.

I believe in placebo and in cup - of - tea - and - a-chat therapy (someone taking an interest and being caring). So I believe in reiki itself, its principles etc, no, not at all. Though, because I understand and believe in placebo as well as cup of tea therapy, I understand why people feel better after such 'treatments'.

Really want to bend your brain ? Read up on falun qigong.
Hooooooboy........

It works..I am a cynic with most things but someone practised Reiki on me and it most definitely made me feel much better emotionally.

3rd level Usui master❣?? i havent practiced for years either. My energy needs unclouding & balance. Working on it??

@AmelieMatisse

Reiki is as effective as using the wind from a hairdryer to knock down a building. I doubt there is any citation to back up Reiki, or anything like it.

hubble bubble toil and trouble

Nope.

Is that pseudoscience?

No.
Someone starts talking energies, aura, chakra, I smile.
Sip my mocha.

Interesting....