Case study: Body composition and bone changes following a thru‐hike of the Pacific Crest Trail by a young female adult

Abstract

A 24‐year‐old premenopausal female adult completed the entire Pacific Crest Trail, an arduous backpacking thru‐hike of 4265 km. Dual‐energy x‐ray absorptiometry measurements were taken before and after the trek. Her body fat percentage dropped from 33.2% to 24.9%, and there was a 52% decrease in visceral adipose tissue mass and area. Total body bone mineral content and bone mineral density (BMD) were retained; however, lumbar BMD decreased 3.8%. The hiker eventually regained this loss of lumbar BMD. A decrease in lumbar BMD despite engaging in load‐bearing activity was also observed in two recent case study reports of male thru‐hikers, suggesting a maladaptive response that warrants further investigation.