The flip side is that women can do endurance exercise over long periods of time without becoming as emaciated as men.  If you look at the people completing thru-hikes of 4-6 months on the Appalachian Trail, the men look dangerously skinny while the women look lean but healthy.  Men's calorie needs become such that the can't carry or eat enough to replace what they are burning.  Maybe women, being more important to the species survival, are more adapted to survive harsh conditions or fewer calories.
				
			 
			
		 
			
				
			
			
				Oil is good, grease is better.
2007 Peter Mooney w/S&S couplers/Terry Butterfly
1993 Bridgestone MB-3/Avocet O2 Air 40W
1980 Columbus Frame with 1970 Campy parts
1954 Raleigh 3-speed/Brooks B72