110 years after the adoption of the second amendment, the US 'militia' was defined as 'all men up to the age of 49'. 'Well-regulated' also means healthy and in good order, in the context of the time. This would suggest that all adult American males (up to 49) should engage in regular training to work as militia units - a militia made up of whatever random yahoos show up with no training is not "well-regulated", using either the modern or antique meanings of the term.