Heat strain in road construction workers during the summer in New Mexico: a preliminary study.

Unlabelled: In the summer season, road construction workers perform physically demanding tasks outdoors, placing them at greater risk for exertional heat illness conditions. Assessing core temperature (Tcore) is critical as it serves as a key indicator of heat strain and helps to estimate the risk of heat-related illness. Despite the increased risk of hyperthermia, previous research has not assessed Tcore in road construction workers in the United States during summer work.

Training Status Influences Regulation of Muscle and PBMC TLR4 Expression and Systemic Cytokine Responses to Vigorous Endurance Exercise.

Introduction: A bout of vigorous endurance exercise transiently activates Toll-like receptor 4 (TLR4) and reduces TLR4 protein expressed on peripheral blood mononuclear cells (PBMCs). Endurance training, on the other hand, reduces TLR4-mediated signaling and minimizes the physiological stress imposed by exercise. Less is known about what occurs in skeletal muscle regarding TLR4 regulation and signaling.

Glutamine Supplementation: A Possible Strategy to Help Mitigate Health Risks of Heat-Related Illness.

A rise in body temperature caused by physical work, including exercise, in a hot climate can lead to heat-related illnesses such as exertional heat exhaustion and stroke. Individuals who work physically demanding occupations in hot environments are at heightened risk of heat injury. The mechanisms that contribute to heat illness resulting from physical work in the heat are complex and include dehydration, tissue ischemia and damage, oxidative stress, and inflammatory events.

Divergent mechanisms regulate TLR4 expression on peripheral blood mononuclear cells following workload-matched exercise in normoxic and hypoxic environments.

Exercise in hypoxia increases immune responses compared with normoxic exercise, and while Toll-like receptor 4 (TLR4) is implicated in these responses, its regulation remains undefined. The purpose of this study was to ) investigate TLR4 regulation during workload-matched endurance exercise in normoxic and hypoxic conditions in vivo and ) determine the independent effects of hypoxia and muscle contractions on TLR4 expression in vitro. Eight recreationally active men cycled for 1 h at 65% of their V̇o in normoxia (630 mmHg) and in hypobaric hypoxia (440 mmHg).

Effect of heat stress on heat shock protein expression and hypertrophy-related signaling in the skeletal muscle of trained individuals.

Muscle mass is balanced between hypertrophy and atrophy by cellular processes, including activation of the protein kinase B-mechanistic target of rapamycin (Akt-mTOR) signaling cascade. Stressors apart from exercise and nutrition, such as heat stress, can stimulate the heat shock protein A (HSPA) and C (HSPC) families alongside hypertrophic signaling factors and muscle growth. The effects of heat stress on HSP expression and Akt-mTOR activation in human skeletal muscle and their magnitude of activation compared with known hypertrophic stimuli are unclear.

Circulating markers of intestinal barrier injury and inflammation following exertion in hypobaric hypoxia.

Hypoxia induced intestinal barrier injury, microbial translocation, and local/systemic inflammation may contribute to high-altitude associated gastrointestinal complications or symptoms of acute mountain sickness (AMS). Therefore, we tested the hypothesis that six-hours of hypobaric hypoxia increases circulating markers of intestinal barrier injury and inflammation. A secondary aim was to determine if the changes in these markers were different between those with and without AMS.

Ibuprofen Increases Markers of Intestinal Barrier Injury But Suppresses Inflammation at Rest and After Exercise in Hypoxia.

Purpose: The purpose of this study was to evaluate the effects of acute ibuprofen consumption (2 × 600-mg doses) on markers of enterocyte injury, intestinal barrier dysfunction, inflammation, and symptoms of gastrointestinal (GI) distress at rest and after exercise in hypobaric hypoxia.

Methods: Using a randomized double-blind placebo-controlled crossover design, nine men (age, 28 ± 3 yr; weight, 75.4 ± 10.

The effect of interval and continuous work on markers of acute kidney injury in a hot environment.

Purpose: To examine the effect of high-intensity interval work (HIIW) and moderate-intensity continuous work (MICW) on markers of acute kidney injury (AKI) and kidney function in a hot environment.

Methods: Nine males completed 2 h of work (2 × 60 min with 10 min passive rest) in a hot environment (40 °C and 15% relative humidity) as either HIIW [2 min at 80% peak oxygen consumption (VOpeak) and 3 min at 30% VOpeak] or MICW (matched for total work of HIIW). Blood and urine samples were collected immediately before (Pre), after (Post), 1 h (1 h Post), and 24 h after (24 h Post) the trials.