Why this post outperforms
HookOpens with a direct attack on a popular belief — "if you think you need to train 6 days a week, watch this." Unavoidable for the target audience.
StructureEstablishes the myth → presents the research → gives the optimal alternative → ends with an actionable prescription. Every section earns the next one.
CTA"Save this and show it to the person at your gym who never takes a rest day." — specific, social, and gives a reason to share.
How you can adapt this: Your science-backed content has all the ingredients of this format. Apply it more aggressively — lead with the myth, build the case, prescribe the fix. Your Post 3 is already close. Sharpen the hook from permission-giving to myth-busting and test the difference.