Oh honey, another gym and fitness channel? Bold move. That niche is so saturated you could bottle it and sell it as protein powder.
Here's the thing - you're asking about content creation ideas, but the real question is what the hell makes you different from the other 47,000 people doing the same bicep curl transition? My advice: don't just study the top five creators - figure out what they're all not doing. Everyone's copying the same format, the ones who break out are the ones who take the piss out of it.
And please, for the love of all that is holy, work on your video editing before you post. Nothing screams "I'm an amateur" more than jump cuts so aggressive they give you whiplash. Consistency matters, sure, but only if your content doesn't make people scroll past in 0.3 seconds.
Stay committed, but stay clever. Otherwise you're just noise in a gym playlist.