I'd agree sa previous reply, matagal ang progress ng exercises, lalo na ang core at wala namang nagfofocus exclusively doon. Hindi ko alam bakit gusto mo ng 2kg to 100kg (ano namang practicality nito?), pero ma-advise ko na mag-full body exercise ka parin, as jumping, push-ups, and other compound exercises involves the core somehow. As for strength, iba-iba definition ng "core strength" eh. Regardless, I'd advise doing isometric before isotonic exercises (e.g. 1-minute plank, then 20x of russian twists). Wag din kalimutan yung ibang "parts" ng core, kasi ang core natin ay hindi lang abs, yung buong gitna sa baba ng chest, simula harap hanggang likod (lower spine banda). Anyway, hindi ko alam kung anong main goal mo, so I'd advise you do your own research. Just gonna say that too much of one exercise is detrimental for your overall health, so mag-ingat palagi.
