Fair question! I'm not a mathematician but I have some engineering background. When that fails, I'll try to apply logic.
If we were in equal physical condition, I should be able to handle about one fourth more load than you. We would be doing the same work carrying the same load but it should be proportionally easier for me. Although, keep in mind that my "machine" is almost 40 lbs heavier than yours, so more effort would be required to move myself and the load, burning one fourth more calories. If we were equally strong - and that's entirely possible - you'd be about one fourth stronger pound for pound and therefore, moving your body and the same load would require far less effort.
A quick look at Google - It takes 62 calories to move 192 lbs 1 ft and 50 calories to move 155 lbs 1 ft. 12 is almost one fourth of 50 so, yes it takes about 1/4 more effort to move me over any distance. That's traveling over level ground. Going uphill could multiply that proportionally, I'd think. There's a formula to calculate the newtons required but I'm not going there tonight.
Very interesting question - thanks for that. Maybe somebody with a background in biomechanics would jump in here and answer the question.
