Ze Mane - nice to see some scientific analysis applied to this question. Those that have done both a Whitney dayhike and a marathon are really the best source for a subjective determination, but it's always good to get some purely objective comparison.
Out of curiosity, any idea what the change in workload is for a mountain climb when you factor in the added weight of a 10 or 15-pound daypack? Fifteen pounds is probably the upper limit for a summer dayhike for most, with maybe 12 as an average. Would that added weight affect the numbers in any significant way, assuming an average male of 165 pounds?
