I like relatively simplistic/clean designs, and more sharp/edgy as opposed to curvy (if that makes sense).
My channel is named after Leonardo Da Vinci's "Vitruvian Man" painting to symbolize perfect human proportions which I advocate through my channel. I focus on the pursuit of physical aesthetics and balance throughout life.
I have attached PNG's/JPG's from some examples of logos/designs I love from people in my industry.
1) Alphalete - Love the simple and edgy logo with the clean writing underneath
2) CGFITNESS - In my opinion, very professional but basic. The white/blue color scheme is unfortunately overplayed in my industry so perhaps white/red/black background would do well, or red/blueish turquoise/white
3) GYMSHARK - super clean and simple with a nice little clean logo
4) BACK and BACK2 - photos of myself which I thought MAY help in the logo creation
5) ME - this was the color scheme I mentioned above which caught my eye when I first saw the photo
I do want to emphasize that although this is a personal channel logo/design, I would prefer it to be "anonymous" so if you incorporate my BACK/BACK2 photos, to make it like a silhouette or shadow, or whatever. That way it represents a fitness movement/brand, not an individual person :)