Marcus competed as a club-level sprinter through his twenties before a recurring injury pushed him toward coaching, and eventually toward writing about the science behind movement rather than just doing it. He spent three years working as a strength and conditioning assistant before moving into health journalism. His writing sits at the intersection of fitness culture and public health guidance — he is particularly interested in where popular fitness trends align with evidence and where they diverge from it. He lives in Birmingham, still trains most days out of habit more than ambition, and has strong but generally unwelcome opinions about stretching.