Most places have to double up on their corn tortillas for a taco because the connective tissue can't handle the weight of the meat and toppings as well as their flour counterparts. (si.com)
Strong muscles mean you'll be able to more easily handle the weight of your growing baby. (pregnancy-info.net)
A good rule of thumb is that a weight is «heavy» you can safely handle the weight for a maximum of 8 to 12 repetitions with proper form. (build-muscle-and-burn-fat.com)