I think carrying technique helps. Grab the bike from the bottom of the top tube and lift it straight up and onto your shoulder. Way easier with diamond frames than step-thrus. That gets the weight off your arms and onto your legs and torso, which are well-suited for the job. All your arms are doing at this point is keeping the bike from falling off your shoulder or swinging around and banging into stuff.

Look at how cyclocross racers carry their bike if you want a visualization.