Abstract
To the Editor:
We thank Dr Bogdasarian for his interest in our article and the many thoughtful questions that he raises. Fundamentally, we agree that research using more rigorous methods will be required to understand the effects of ultra light hiking techniques on illness and injury experienced by long-distance hikers. There are limitations to our use of a structured cross-sectional survey instrument to assess some of the associations between footwear, packweight, and illness and injury experienced by long-distance hikers in a single year. Although we did inquire about diarrhea, we did not include this in our final report because there were concerns with our ability to adjust for many factors that could be associated with this disorder, such as type and frequency of water purification, water sources, and hygiene to name a few. We did not explore the association between diarrhea, packweight, and footwear because the association would be ambiguous at best.
We re-examined our data to see if there was a relationship between age, footwear, and packweight. An association was found with younger hikers carrying less weight and wearing less rigid footwear (running shoes). Of note, there were not many hikers in the over 50 age group, which limits our ability to judge how age could have affected injury patterns. Dr Bogdasarian suggests that hikers carrying heavier packs would be able to travel for longer periods of time; however, it is the authors' experience that the opposite would be true. Hikers carrying less weight are able to spend their energy on walking rather than hauling unnecessary gear.
We are unaware of any studies that have examined military experience with packweight, footwear, and illness and injury. Although military as opposed to recreational hiking differs in the need to carry supplies and protective equipment, it would be of interest to know whether there are any data that have examined the association between use of different packs, weights, and footwear on important health outcomes. Ultimately our study suggests the need for multiyear prospective cohort studies using a method such as routine diary or electronic outcome monitoring to characterize predictors of and protectors from illness and injury among long-distance hikers.