Comment on Collins, C.N.; et al. Body Composition Changes of United States Smokejumpers during the 2017 Fire Season. Fire 2018, 1, 48

Abstract

In the recent manuscript by Collins et al [...]

Reply to Ruby, B. Comment on Collins, C.N., et al. Body Composition Changes of United States Smokejumpers during the 2017 Fire Season. Fire. 2018, 1, 48. Fire 2019, 2, 15

“…"Since fat free mass is also inclusive of total body water, even subtle variations can increase the measurement errors associated with the skinfold technique." [1]. Ruby [1] does not recognize recent literature showing that the effects of hydration status are most relevant when three and four compartment models that include total body water are used [20], and are less important with two compartment models as was used in Collins et al [2].…”

“…"The authors outline a misconception of what body composition analyses may provide agencies and fire crews in relation to detecting underlying cardiovascular risk." Ruby's [1] statements are not necessarily informed by current research on the importance of skinfold measurements as indicators of health status or on the importance of cardiovascular health for WLFF. Recent results from a large study (n = 870) of seemingly healthy white males showed that skinfold thickness is an independent predictor of all-cause mortality over 27.7 years of follow-up [17].…”

“…[1]. Ruby [1] does not recognize recent literature showing that the effects of hydration status are most relevant when three and four compartment models that include total body water are used [20], and are less important with two compartment models as was used in Collins et al [2]. Furthermore, although hydration may affect skinfold thickness, it does not affect skin compressibility in healthy males at up to 2.11% body weight change [21].…”

“…"It is also unclear when the post-season measures were obtained relative to final wildfire assignments and accumulated days off." [1]. The methods state that post-season measurements were taken on 21 September 2017, immediately after most subjects returned to the base after final assignment.…”

“…"It appears that neither fat nor fat free mass demonstrated a statistically significant change and therefore was not included in the results." [1]. Body fat percentage (BF%) is probably the most evaluated body composition component in sports [25] thus BF% and body weight were the focus of Collins et al [2] using methods similar to those described in [26], and statistical results for these were presented.…”