Engaging Fitness YouTube Thumbnail Branding

I run a YouTube fitness channel centred on home workouts. It is primarily a 12-month workout series providing a
30-minute Legs, Bums, Tums
45-minute Full Body PUMP
20-minute HIIT Bonus
workouts each month. I want every thumbnail to scream “fitness” the second a viewer scrolls past. Up to now each video has its own look, so my click-through rate is inconsistent. I’m looking for a recognisable, cohesive thumbnail style that immediately tells people they’re about to watch an energetic workout and, in turn, lifts my CTR.

Here’s what matters to me:
• A visual theme that feels purpose-built for fitness content. I’m not locked into “bright and colourful,” “minimalistic,” or “dark and edgy”; I just need whatever combination of colour, typography, and layout will resonate with an active-lifestyle audience.
• Imagery and text that literally shows what the video covers. If the session is legs, I want the thumbnail to feature a clear leg-day exercise; if it’s HIIT, a dynamic action shot that captures the intensity. The picture should describe the content at a glance, not rely on and show me as the instructor.

I already have 29 video thumbnails requiring streamlined. Have a look at FIT WITH JAMIESON to see what you think you could do.