What weight should I be at this age if i want to be a heavyweight fighter?
at 5’7 your ideal weight class would be LW, you would give up a significant reach advantage in almost every fight at any higher weight class the ideal height for LHW is 6-6’4 and for HW 6’2-6’6 although there are exceptions like Fedor the greatest hw ever at 6′ 233 and Igor vovchanchyn the 5’8 205-230 wrecking machine also tyson is only about 5’11 and was 215 in his prime