Part of the feeling of meditation practice being a workout comes from the attitude behind it. Your effort flows from that.
My current favourite meditation teacher is Mingyur Rinpoche. Here is a 3 minute clip from him on “being vs. trying” in meditation. This might address your experience:
Looking at the old meditation texts, there are about 30 variations on sitting meditation practice. The most common is to bring your attention to breathing, and return to it when you get distracted. But you could also bring your attention sequentially to each portion of your body (the classic “body scan” meditation). Or rest your attention on your whole body. Or bring your attention to either a persistent sound, or the the entire sound field–all the ambient sounds around you.
The Muse headset with it’s near-instant feedback is great. But it’s also a bit too easy to get goal-oriented with it. I’ve enjoyed sitting with the Muse, turning off the birds, and not trying to get anywhere specific. Just notice that sometimes there is a lot of wind, and sometimes it’s still. It’s more interesting, than instructive.
You could just rest your mind in the present moment, but that is difficult. It’s helpful to come back to something persistent–body, breathing, sounds, sensations. The point is to train mind to be present, and to return to that sense of presence each time you discover that you are distracted.
Bringing your attention to the breath has lots of options. The tightest is to count your breaths, as a way to remind you to come back to the experience. Or, you could feel the sensations in your belly/diagphram as you breathe in and out. Or you could notice the sensation of only the outbreath–letting your attention disolve into the room at the end of each outbreath, and letting mind rest during the inbreath.
You might want to experiment with meditating with eyes open, to bring in more a sense of awareness of the room, while also lightly attending to the breath, or sound, or body sensations. In my experience, it doesn’t seem to work so well to bring your attention to a visual object, or to let your eyes wander around the room. Best to let them rest, and notice the whole environment using peripheral vision.
Sometimes it’s helpful to talk to another person about meditation. You can learn a lot from YouTube and books, but talking to a human demystifies it. Depending on your city, there are probably several places, usually Buddhist, that teach meditation for free or a nominal charge. Google “meditation in xxx” to see who is teaching mindfulness meditation near you.