James A. Hodgdon’s research while affiliated with Naval Aerospace Medical Research Laboratory and other places

... The majority of early investigations into the anxiolytic effects of acute aerobic exercise examined individuals without a clinical diagnosis of an anxiety disorder. Small, but statistically significant, transient reductions in state anxiety (approximately 1/6-1/2 standard deviation) following acute bouts of aerobic exercise (compared to control conditions) have been consistently demonstrated in several quantitative reviews and meta-analyses (Ensari et al. 2015;McDonald and Hodgdon 1991;Petruzzello 2012;Petruzzello et al. 1991;Landers and Petruzzello 1994). One review quantified this change as approximately a 7.7-15.4% ...

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Exercise and Anxiety

... On the view of validate and accuracy, most of the published papers measuring impedance value (Z) were done by the clinical analytic supine lying position BIA and few studies were done by the standing position BIA. The hand-to-foot BIA model, performed by tetra-polar gel electrodes in a supine lying position, had been shown great accuracy in measurement of fat free mass (Lukaski et al., 1986;Segal et al., 1988). The accuracy of standing position BIA remained a mystery for commercial consideration so as to misunderstand the accuracy of standing position BIA to be less accurate than that of the supine lying position BIA. ...

Reference:

The validity and accuracy in foot-to-foot bioelectrical impedance analysis measuring models referenced by dual-energy X-ray absorptiometry in body composition in standing position

... During the Static dive, the body temperatures, heart rate and oxygen consumption remained unchanged, reflecting an absence of significant thermal strain [35]. In contrast, finning increased oxygen consumption and heart rate, and the values were consistent with other indicators of increased energy expenditure and heart rate in these conditions [3,10,42,51]. The increase in oxygen consumption during finning was to be expected and was related to the increase in body temperature [7]. ...

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Alterations in Body Fluid Balance During Fin Swimming in 29°C Water in a Population of Special Forces Divers

... This is also one of the more labile fat depots under control of the service member through exercise and nutritional habits. Furthermore, the circumference-based method is blind to genetic variations in subcutaneous fat distribution elsewhere on the body making it fairer and not racially biased (28,71). ...

Reference:

Body Composition and Military Performance—Many Things to Many People

... Due to sleep's relation to stress and cortisol, exercise may therefore affect sleep quality in a favorable manner as well. A wide breadth of research has suggested that, if controlled for extraneous variables like time management, preferred mode of exercise, etc., exercise has widespread positive effects on mood and typically shows significant reductions in perceived stress (Matamura et al., 2014;Bartholomew et al., 2005;Guszkowska & Sionek, 2009;McDonald & Hodgdon, 1991;Osei-Tutu & Campagna, 2005). In addition, evidence suggests that exercise garners better same-day cortisol reduction -achieving a lower concentration for the evening, as opposed to not exercising that day, which may aid sleep onset. ...

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THE EFFECTS OF ACCUMULATED VS. CONTINUOUS EXERCISE SESSIONS ON EVENING CORTISOL CONCENTRATION AND PERCEIVED MOOD STATE

... Over the past several decades, these circumference-based body fat estimation techniques have proven to be useful in the military setting for a variety of reasons, particularly because of their low cost and acceptable validity compared with laboratory techniques such as dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), or air displacement plethysmography (ADP) (31,99). Compared with other cost-effective methods such as skinfold assessments (which were briefly used by the army in an interim phase (37)), circumference measures are easier to learn and yield more precise results when performed by novice testers (49,86). In addition, circumference measures are less affected by sources of error such as hydration status, electrode placement, body positioning, menstrual cycle status, and pretesting dietary intake compared with more sophisticated laboratory techniques such as bioimpedance analysis (86). ...

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Military Body Composition Standards and Physical Performance: Historical Perspectives and Future Directions

... Shahzad [49] demonstrates individual differences in perceiving the thermal environment, differences in individual preferences and the dynamic aspect of thermal comfort indicating that occupants keep changing their mind [50]. Heaney et al. [51] found gender differences in thermoregulatory responses in a heat tolerance exposure (between 43.3°C and 60°C) experiment among US navy men and women. They found no significant core temperature differences between male and female subjects, while the skin temperature changes as well as sweating rate were significantly different. ...

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Patterns of thermal preference and visual thermal landscaping model in the workplace

... Subsequent to this work, Hodgdon, Fitzgerald, and Vogel (1990) conducted an experiment to determine how strongly ratings of military appearance and fatness were associated, and to consider how reliable and valid assessments of fatness can be made in a military population that includes personnel of both genders, and various ages and races. Subjects were 1326 US Army active duty personnel, including men and women, whose body composition was established by hydrodensitometry. ...

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Health and Job-Specific Body Composition Standards for the US Air Force. Volume 1, Final Report

... Thermoregulatory behaviour can be delayed in acute hypoxic conditions by a blunted cold sensation in the toes upon local cooling (Golja, Kacin, Tipton, Eiken, & Mekjavic, 2004), although this is not a universal observation. No changes were reported for thermal sensation and thermal comfort during local (Amon et al., 2012;Keramidas et al., 2014Keramidas et al., , 2015O'Brien et al., 2015) and whole-body cooling (Fukazawa et al., 2013;Keramidas et al., 2019;Massey et al., 2018;Reading, Roberts, Hodgdon, & Pozos, 1996). If anything, a combination of mild hypothermia induced by whole-body water immersion and acute hypoxia tended to enhance comfort in hands that were immersed separately in 8 • C water (Keramidas et al., 2019). ...

Reference:

Integrative crosstalk between hypoxia and the cold: Old data and new opportunities

... The findings from these studies suggested that a passive microclimate garment (ice vest) could be used to reduce thermal strain in the fleet (Pimental & Avellini, 1989). Preliminary field studies conducted at thel^aval Health Research Center, San Diego, CA, demonstrated that the ice vest not only reduced thermal strain but also reduced ratings of tension/anxiety during shipboard operations (Banta & Braun, 1992;Burr, Banta, Coyne, Hodgdon, & Chesson, 1990; *Modified from: U.S. Navy Manual of Naval Preventive Medicine. Chapter 3, Ventilation and thermal stress ashore and afloat. ...

Reference:

The Effects of a Passive Microclimate Cooling System on Human Thermoregulation in the Heat at Rest