Appl Physiol Nutr Metab
January 2025
The extent to which groundskeepers experience thermal and cardiovascular strain, dehydration, and accompanying declines in kidney function during work in hot-humid conditions is unknown. Demographics, thermal and cardiovascular strain, hydration, and kidney function were assessed in 20 groundskeepers (18 men; mean ± SD, age = 37.9 ± 8.
View Article and Find Full Text PDFJ Occup Environ Hyg
May 2025
Construction workers are 13 times more likely to die from heat-related illnesses than workers in other job industries. This elevated risk is attributed to excessive heat stress from environmental exposure, metabolic heat generated from physical labor, and the insulating effects of protective clothing. Levels of heat stress may vary across job types, reflecting the diversity of tasks performed and the work environment.
View Article and Find Full Text PDFAm J Physiol Regul Integr Comp Physiol
June 2025
Agricultural workers are at high risk for heat-related illnesses when performing heavy labor in hot conditions. Occupational heat strain, the physiological response to heat stress, is hypothesized to be common in this worker population but has rarely been measured objectively through core body temperature (T). The objective of this study was twofold: ) evaluate workday heat strain and ) examine the trajectory of heat exposure and T from the workday through the off-work hours to advance understanding of the recovery process and conditions of heat-exposed agricultural workers.
View Article and Find Full Text PDFIntroduction: Higher work rates may be sustainable when maintaining target rating of perceived exertion (RPE) compared to maintaining target heart rate (THR) during high-intensity interval training (HIIT) exercise in hot conditions, but may also result in greater thermal strain and cardiovascular drift, as well as greater decrements in maximal oxygen uptake ( O).
Purpose: To test the hypotheses that maintaining target RPE compared to THR during HIIT in the heat results in 1) smaller work rate adjustments, 2) greater thermal and cardiovascular strain, and 3) larger decreases in O.
Methods: Eight adults (4 women) completed a graded exercise test on a cycle ergometer in 22°C and then 4 cycling trials in 35°C, consisting of an 8-min warm-up at 70% maximal heart rate (HR) or 12 RPE followed by 1 (15 and 15) or 5 (43 and 43) rounds of HIIT (1 round = 4 min work at 90% HR or 17 RPE and 3 min recovery at 70% HR or 12 RPE) totaling 15 min or 43 min of exercise, respectively.
Introduction/purpose: The purpose of this study was to test the hypothesis that cardiovascular (CV) drift and associated decrements in maximal oxygen uptake (V̇O 2max ) are greater in high-fit compared with low-fit women during exercise at the same %V̇O 2max , but comparable at the same rate of metabolic heat production.
Methods: Six high-fit (HI) and six low-fit (LO) women cycled in 35°C for 15 or 45 min at the same relative intensity (60% V̇O 2max ; 15REL and 45REL) or fixed rate of heat production (500 W; 15FX and 45FX), immediately followed by a graded exercise test to measure V̇O 2max . The separate 15- and 45-min trials permitted measurements of V̇O 2max over the same time interval as CV drift.
Appl Physiol Nutr Metab
December 2023
Heart rate drifts upward over time during interval exercise and during exercise in hot conditions. As such, work rate must be lowered to maintain target heart rate. The purpose was to characterize acute work rate adjustments during high-intensity interval training based on target heart rate.
View Article and Find Full Text PDFInt J Environ Res Public Health
March 2023
Cardiovascular drift-a progressive increase in heart rate (HR) and decrease in stroke volume (SV) during prolonged exercise-is exacerbated by heat stress and thermal strain, and often accompanied by a decrease in work capacity (indexed as maximal oxygen uptake [V.O]). To attenuate physiological strain during work in the heat, use of work:rest ratios is recommended by the National Institute for Occupational Safety and Health.
View Article and Find Full Text PDFRates of anemia among agricultural workers, who are also at risk for kidney injury and chronic kidney disease of unknown cause (CKDu), are unknown. We evaluated body composition through the sum of three skinfolds among 203 male sugarcane cutters and assessed the relationship of variables related to nutrition, anemia (hemoglobin < 13 g/dL), and elevated hemoglobin A1c (HbA1c ≥ 5.7%) with estimated glomerular filtration rate (eGFR) using linear regression.
View Article and Find Full Text PDFKidney Int Rep
September 2021
Introduction: Agricultural workers laboring in thermally stressful environments are at increased risk for kidney injury and chronic kidney disease of unknown origin (CKDu), and their environmental and occupational exposures have been considered to be important risk factors. This study examined the effects of repeated kidney stress from the simultaneous strain of work and other factors experienced by workers in Guatemala during a typical workweek.
Methods: We collected data from 107 sugarcane workers across 7 consecutive work shifts.
Objectives: To evaluate impact of electrolyte supplementation on hydration status and health outcomes in Guatemalan agricultural workers performing heavy work under hot climatic conditions.
Methods: A 3-week pragmatic trial was conducted with a group of 50 workers during the 2017 to 2018 sugarcane harvest. Workers received an electrolyte hydration intervention during 2 of the 3 weeks.
Background: Iodine deficiency is not seen as a public health concern in the US. However certain subpopulations may be vulnerable due to inadequate dietary sources. The purpose of the present study was to determine the dietary habits that influence iodine status in young adult men and women, and to evaluate the relationship between iodine status and thyroid function.
View Article and Find Full Text PDFMore than 47,000 people in the United States died from opioid drug overdoses in 2017. Among college students, opioid drugs are the second most abused drug. This study aimed to examine if an educational intervention impacted college students' attitudes towards prescription opioid drugs (POD).
View Article and Find Full Text PDFPurpose: This investigation had three purposes: (a) to evaluate changes in hydration biomarkers in response to a graded rehydration intervention (GRHI) following 3 days of water restriction (WR), (b) assess within-day variation in urine concentrations, and (c) quantify the volume of fluid needed to return to euhydration as demonstrated by change in U.
Methods: 115 adult males and females were observed during 1 week of habitual fluid intake, 3 days of fluid restriction (1000 mL day), and a fourth day in which the sample was randomized into five different GRHI groups: no additional water, CON; additional 500 mL, G; additional 1000 mL, G; additional 1500 mL, G; additional 2250 mL, G. All urine was collected on 1 day of the baseline week, during the final 2 days of the WR, and during the day of GRHI, and evaluated for urine osmolality, color, and specific gravity.
Int Arch Occup Environ Health
October 2019
Objective: Agricultural workers worldwide exposed to heat stress could be at the risk of kidney injury, which could lead to chronic kidney disease of an unknown origin (CKDu). Hydration has been promoted as a key measure to reduce kidney injury. In the presence of a hydration intervention, the incidence of acute kidney injury (AKI) was calculated in a sugarcane worker population in Guatemala and several risk factors were evaluated.
View Article and Find Full Text PDF