Aaron Caldwell

U.S. Army Research Institute of Environmental Medicine · Thermal and Mountain Medicine Division

The primary means for disseminating sport and exercise science research is currently through journal articles. However, not all studies, especially those with null findings, make it to formal publication. This publication bias towards positive findings may contribute to questionable research practices. Preregistration is a solution to prevent the pub...

Researchers often rely on analysis of variance (ANOVA) when they report results of experiments. To ensure a study is adequately powered to yield informative results when performing an ANOVA, researcher can perform an a-priori power analysis. However, power analysis for factorial ANOVA designs is often a challenge. Current software solutions do not...

The average environmental and occupational physiologist may find statistics are difficult to interpret and use since their formal training in statistics is limited. Unfortunately, poor statistical practices can generate erroneous or at least misleading results and distorts the evidence in the scientific literature. These problems are exacerbated wh...

Dankel & Loenneke (2019) recently presented a new approach to identifying subgroups in parallel group study designs. Here, we briefly discuss our statistical concerns with proposed approach. We reveal that the error rates of the Danke-Loenneke approach are much higher than the claimed 5%, and that these error rates are dependent on numerous factors...

Recent discussions in the sport and exercise science community have focused on the appropriate use andreporting of effect sizes. Sport and exercise scientists often analyze repeated-measures data, from whichmean differences are reported. To aid the interpretation of these data, standardized mean differences(SMD) are commonly reported as description...

Exertional heat stroke (EHS) is an ongoing challenge for military personnel, for athletes and for individuals with occupational stressors that involve prolonged activity in hot environments. We recently showed that body mass index (BMI) was significantly associated with increasing risk for EHS in a cohort of activity duty U.S. Soldiers between 2016...

Background Adolescence is a critical time for establishing behaviors. 24-hour movement behaviors, including physical activity, sleep, and sedentary time, are likely to influence obesity, cardiovascular, and cognitive health. The aim was to examine associations between 24-hr movement behaviors, cardiometabolic health and cognitive functions in adole...

Objectives: We aimed to examine the bias for statistical significance using published confidence intervals in sport and exercise medicine research. Design: Observational study. Methods: The abstracts of 48,390 articles, published in 18 sports and exercise medicine journals between 2002 and 2022, were searched using a validated text-mining algo...

Equivalence testing is arguably under utilized by experimental researchers. Due to limited software support for such analyses, and little education on the topic in graduate programs, the utilization of equivalence testings still appares to be low. One option for equivalence testing is the use of two one-sided tests (TOST). The TOSTER R package and...

Exertional heat stroke (EHS) remains a persistent threat for individuals working or playing in the heat, including athletes, the military and emergency service personnel. However, influence of biological sex and/or body mass index (BMI) on the risk of EHS remain poorly understood. The purpose of this study was to retrospectively assess the influenc...

Exertional heat stroke (EHS) is a potentially lethal condition resulting from high core body temperatures (T C ) in combination with a systemic inflammatory response syndrome (SIRS) with varying degrees of severity across victims, and limited understanding of the underlying mechanism(s). We established a mouse model of severe EHS in an effort to id...

Military and/or emergency services personnel may be required to perform high-intensity physical activity during exposure to elevated inspired carbon dioxide (CO 2 ). Although many of the physiological consequences of hypercapnia are well characterized, the effects of graded increases in inspired CO 2 on self-paced endurance performance have not bee...

Recently, a group of editors from physiotherapy journals wrote a joint editorial on the use of statistics in their journals. Like many editorials before them, the editors, who were not statistical experts themselves, put forth numerous recommendations to physiotherapy researchers on how to analyze and report their statistical analyses. This editori...

Introduction To improve the rigor of science, experimental evidence for scientific claims ideally needs to be replicated repeatedly with comparable analyses and new data to increase the collective confidence in the veracity of those claims. Large replication projects in psychology and cancer biology have evaluated the replicability of their fields...

This investigation sought to assess whether single or repeated bouts of ischemic preconditioning (IPC) could improve oxyhemoglobin saturation (SpO2) and/or attenuate reductions in muscle tissue saturation index (TSI) during submaximal hypoxic exercise. Fifteen healthy young men completed submaximal graded exercise under four experimental conditions...

Aim: We aimed to examine the bias for statistical significance using published confidence intervals in sport and exercise medicine research. Method: The abstracts of 48,390 articles, published in 18 sports and exercise medicine journals between 2002 and 2022, were searched using a validated text-mining algorithm that identified and extracted ratio...

Telemetric temperature capsules are frequently utilized to measure deep body temperature. Whereas most methods to measure temperature are conducted at a single site (e.g., rectal temperature), the location of ingested telemetry capsules varies. If distinct regions of the gastrointestinal tract have different temperatures, the measurements obtained...

Introduction Exertional heat illnesses remain a major threat to military service members in the United States and around the world. Exertional heat stroke (EHS) is the most severe heat illness, characterized by core hyperthermia and central nervous system dysfunction. Per current Army regulations, iced-sheet cooling (ISC) is the recommended immedia...

[This corrects the article DOI: 10.3389/fspor.2021.722305.].

Scientists rely upon an accurate scientific literature in order to build and test new theories about the natural world. In the past decade, observational studies of the scientific literature have indicated that numerous questionable research practices and poor reporting practices may be hindering scientific progress. In particular, 3 recent studies...

The purpose of this study was to investigate the relationship between volume regulatory biomarkers and the estrogen to progesterone ratio (E:P) prior to and following varying methods and degrees of dehydration. Ten women (20 ± 1 year, 56.98 ± 7.25 kg, 164 ± 6 cm, 39.59 ± 2.96 mL•kg•min ⁻¹ ) completed four intermittent exercise trials (1.5 h, 33.8 ±...

The purpose of the study was to determine if repeated exertional heat injuries (EHIs) worsen the inflammatory response and subsequent organ damage. We assessed the impact of a single EHI bout (EHI0) or 2 separate EHI episodes separated by 1 (EHI1), 3 (EHI3), and 7 (EHI7) days in male C57BL/6J mice (N = 236). To induce EHI, mice underwent a forced r...

Introduction: To improve the rigor of science, experimental evidence for scientific claims ideally needs to be replicated repeatedly with sufficiently similar procedures to increase the collective confidence in the veracity of those claims. Large replication projects in psychology, cancer biology and social science have evaluated the replicability...

Background: Debate continues over whether or not individuals with low total water intake (TWI) are in a chronic fluid deficit (i.e., low total body water) [ 1 ]. When women with habitually low TWI (1.6 ± 0.5 L/day) increased their fluid intake (3.5 ± 0.1 L/day) for 4 days 24-h urine osmolality decreased, but there was no change in body weight, a p...

Historical environmental data from the Boston Marathon affords a pragmatic opportunity to retrospectively quantify how the 2007 earlier start time altered the odds of runner exposures to environmental conditions associated with exertional heat illness. Purpose: To compare the wet bulb globe temperature (WBGT) index and other environmental paramet...

Researchers often rely on analysis of variance (ANOVA) when they report results of experiments. To ensure that a study is adequately powered to yield informative results with an ANOVA, researchers can perform an a priori power analysis. However, power analysis for factorial ANOVA designs is often a challenge. Current software solutions do not allow...

Recent discussions in the sport and exercise science community have focused on the appropriate use and reporting of effect sizes. Sport and exercise scientists often analyze repeated-measures data, from which mean differences are reported. To aid the interpretation of these data, standardized mean differences (SMD) are commonly reported as a descri...

Selecting the most appropriate performance test is critical in detecting the effect of an intervention. In this investigation we: 1) used time-trial (TT) performance data to estimate sample size requirements for test selection and 2) demonstrated the differences in statistical power between a repeated measures ANOVA (RM-ANOVA) and analysis of covar...

The average environmental and occupational physiologist may find statistics are difficult to interpret and use since their formal training in statistics is limited. Unfortunately, poor statistical practices can generate erroneous or at least misleading results and distorts the evidence in the scientific literature. These problems are exacerbated wh...

This proof-of-concept study used a web application to predict runner sweat losses using only energy expenditure and air temperature. A field study (FS) of n = 37 runners was completed with n = 40 sweat loss observations measured over 1 h (sweat rate, SR). Predictions were also compared with 10 open literature (OL) studies in which individual runner...

Recent evidence suggests prolonged sitting strains the arteries through angulations that create turbulent blood flow. This turbulent flow reduces flow-mediated dilation (FMD), a key indicator of vascular health. The purpose of this study was to determine if arterial angulations (through sitting or standing), shear stress (through local heating), or...

We investigated the impact of nutrient intake on hydration biomarkers in cyclists before and after a 161 km ride, including one hour after a 650 mL water bolus consumed post-ride. To control for multicollinearity, we chose a clustering-based, machine learning statistical approach. Five hydration biomarkers (urine color, urine specific gravity, plas...

Purpose This study aimed to examine the psychological factors (knowledge, barriers and facilitators) that can contribute to hydration-related behaviors (i.e., fluid intake) in the general population and how these relate to physical health. Methods A structured survey was developed to examine the links between hydration knowledge (29 items), attitu...

The primary means of disseminating sport and exercise science research is currently through journal articles. However, not all studies, especially those with null findings, make it to formal publication. This publication bias towards positive findings may contribute to questionable research practices. Preregistration is a solution to prevent the pu...

Cancer associated bodyweight loss (cachexia) is a hallmark of many cancers and is associated with decreased quality of life and increased mortality. Hepatic function can dramatically influence whole body energy expenditure and may therefore significantly influence whole body health during cancer progression. Purpose: To examine alterations in mar...

Standing is commonly recommended to reduce sedentary behavior in the workplace; however, constrained prolonged standing has also been linked to musculoskeletal symptoms, such as low back pain (LBP). Light physical activity breaks, such as walking, may change lumbar spine posture enough to reduce LBP during standing. This study assessed the effectiv...

Objective: Achieving and maintaining an optimal level of hydration has significant implications for both acute and chronic health, yet many hydration assessments are not feasible for the general public. Urinary frequency (UF) is a reliable method to self-assess hydration status in healthy individuals, and thirst can provide additional sensory infor...

Background Eating disorders are serious psychological disorders with long term health impacts. Athletic populations, tend to have higher incidences of eating disorders compared to the general population. Yet there is little known about athletes’ eating disorder knowledge and how it relates to their confidence in their knowledge. Therefore, the purp...

SAS statistical output from current study

Regression analysis of the relationship between average confidence and total scores on eating disorder knowledge Regression of average confidence on total scores. Average confidence was calculated by summing all confidence scores then dividing by total possible confidence (corresponding to a confidence score of 5 for each question). We noted no sig...

Eating disorder knowledge survey Survey that was sent to participants by Google docs survey.

Regression analysis of age of participant and total score of eating disorder knowledge Regression of age on total scores, we noted a small significant relationship between age and total score (F(1, 49) = 9.17, R2 = 0.16, b = .0321, p < 0.05).

Raw data Title page is the first tab. All other tabs describe data analysis/sorting in that particular tab.

SAS code for statistical analysis

Purpose: Standing workstations have recently been promoted as a healthy alternative to sitting. However, it is unknown how prolonged standing affects arterial stiffness, a prognostic indicator of cardiovascular health. The purpose of this study was twofold: to observe changes in arterial stiffness, as assessed by pulse wave velocity (PWV), with a...

Data for cognition, mood, and mental task load Data included in this dataset includes data for the analyses of cognitive performance, mood state, and mental task load.

Data output for statistical analysis Each section of the results section of the paper is broken down in the SPSS output by each multivariate analysis.

Physiology data reported in the study The data in this set includes physiological data (heart rate, skin temperature, etc).

Introduction: Obesity and hypohydration independently affect postsynaptic endothelial function, but it is unknown if hypohydration affects lean and obese individuals differently. Purpose: To examine the effect of hypohydration on postsynaptic cutaneous vasodilation and sweating in men with high and low adiposity (HI- and LO-BF, respectively). M...

Background The independent effects of hypohydration and hyperthermia on cognition and mood is unclear since the two stresses often confound each other. Further, it is unknown if obese individuals have the same impairments during hyperthermia and hypohydration that is often observed in non-obese individuals. Methods The current study was designed t...

Objectives: To observe the effects of endurance cycling in the heat on renal function. Secondarily, we investigated the effect of ibuprofen ingestion on kidney stress. Design: Randomized, placebo controlled and observational methods were utilized. Methods: Forty cyclists (52±9y, 21.7±6.5% body fat) volunteered and completed an endurance cyclin...

In response to recommendations to redefine statistical significance to P ≤ 0.005, we propose that researchers should transparently report and justify all choices they make when designing a study, including the alpha level.

In response to recommendations to redefine statistical significance to P ≤ 0.005, we propose that researchers should transparently report and justify all choices they make when designing a study, including the alpha level.

In response to recommendations to redefine statistical significance to p ≤ .005, we propose that researchers should transparently report and justify all choices they make when designing a study, including the alpha level.

Background: The procedure of wrapping a heat casualty in ice-water soaked bed sheets to reduce core temperature has received little investigation, despite the practice and recommendation for its use in some military settings. Thus, the purpose of this study was to investigate the cooling efficacy of ice-sheet cooling (ISC) following exertional hyp...

Purpose: Prior evidence indicates that acute heat stress and aerobic exercise independently reduce arterial stiffness. The combined effects of exercise and heat stress on PWV are unknown. The purpose of this study was to determine the effects of heat stress with passive heating and exercise in the heat on arterial stiffness. Methods: Nine partic...

Consensus guidelines have attempted to standardize the measurement and interpretation of pulse wave velocity (PWV); however, guidelines have not addressed whether hydration status affects PWV. Moreover, multiple studies have utilized heat stress to reduce arterial stiffness which may lead to dehydration. This study utilized two experiments to inves...

The training of novice and competitive athletes involves the incorporation of unaccustomed exercise, likely to result in skeletal muscle tissue damage. The initial response, known to result in muscle soreness and swelling, and decreased forced production, is followed by a secondary inflammatory response integral in the skeletal muscle repair and re...

A short presentation demonstrating how to measure sweat gland activation