Fat-Free Mass Is Positively Associated With Urine Specific Gravity in Athletes and Active Adults: A Quantitative Review.

Urine specific gravity (USG) is a commonly used assessment method to estimate the prevalence of hypohydration, typically based on a common threshold of ≥ 1.020. Some research has shown that USG can vary based on body size and composition, but the evidence to date is limited.

Reliability and minimal detectable change of the MX3 hydration testing system.

Assessing hydration status outside of laboratories can be challenging given that most hydration measures are invasive, stationary, costly, or have questionable validity. This study investigated the within-day, test-retest reliability, and minimal detectable change (MDC) of the MX3 Hydration Testing System (MX3 Diagnostics), a relatively low cost, noninvasive, and portable method to measure saliva osmolality. Seventy-five adults (44 men, 31 women; 29.

Associations between urine specific gravity and race/ethnicity at the population level: Implications for hydration status categorization.

Objective: We aimed to evaluate how urine specific gravity (USG) and rates of supposed hypohydration vary by race/ethnicity, and to examine how adjustment for several important factors impacts estimated USG.

Methods: Using the National Health and Nutrition Examination Survey, this cross-sectional study evaluated a total of 4195 (2098 female, 2097 male) Americans and categorized them as supposedly hypohydrated (USG≥1.020) or not using spot urine samples.

Effects of food bar chewing duration on the physiologic, metabolic, and perceptual responses to moderate-intensity running.

Purpose: Chewing duration can affect food particle size, gastric processing, and postprandial glycemia, but these effects have not been investigated with exercise. This study examined how the chewing duration of a food bar impacts glycemic and metabolic responses, gastrointestinal (GI) symptoms, psychological affect, and performance during endurance running.

Methods: This randomized, unblinded, crossover study had 15 males (35.

Differences in urine creatinine and osmolality between black and white Americans after accounting for age, moisture intake, urine volume, and socioeconomic status.

Urine osmolality is used throughout research to determine hydration levels. Prior studies have found black individuals to have elevated urine creatinine and osmolality, but it remains unclear which factors explain these findings. This cross-sectional, observational study sought to understand the relationship of self-reported race to urine creatinine and urine osmolality after accounting for age, socioeconomic status, and fluid intake.

Trunk-to-leg-volume ratio is not associated with bone density or fracture risk in middle-aged adults: results from the National Health and Nutrition Examination Survey.

Unlabelled: Unlike a high body mass index or waist circumference, a high trunk-to-leg-volume ratio does not associate with a lower risk of osteopenia/osteoporosis at the femoral neck. While elevated TLVR showed a suggestive association with a history of wrist fracture in women, additional research is needed to confirm this suggestion.

Purpose: Body mass index (BMI) and waist circumference (WC) are commonly used to predict bone health, which is typically assessed via bone mineral density (BMD).

Anxiety and visceral sensitivity relate to gastrointestinal symptoms in runners but not pre- or during-event nutrition intake.

Background: Previous research has shown anxiety to relate to gastrointestinal (GI) symptoms in endurance athletes, but it remains unclear whether competition-related fueling is impacted by anxiety. This study examined whether general anxiety, pre-race anxiety, and visceral sensitivity were associated with nutritional intake before and during endurance running races.

Methods: A total of 149 (86 female, 63 male) runners participated in this cross-sectional survey study.

A single bout of breast milk expression does not increase resting metabolic rate.

Introduction: Breastfeeding women have elevated resting metabolic rate (RMR); however, whether a single bout of lactation increases RMR is unknown. This study aimed to determine if a single bout of lactation acutely increased RMR.

Methods: Twenty-two lactating women (age: 31 ± 0.

Visceral sensitivity correlates with gastrointestinal symptoms in runners during training but does not negatively impact peri-exercise fueling.

Objectives: This study aimed to evaluate the associations between several psychological factors (stress, anxiety, body vigilance, and visceral sensitivity) and gastrointestinal (GI) symptoms in runners, as well as whether any of these factors impact pre-exercise and during-exercise fueling.

Methods: A virtual/online observational survey-based study with 82 (43 male and 39 female) runners was conducted. The Perceived Stress Scale (PSS)-14, State-Trait Inventory for Cognitive and Somatic Anxiety (STICSA-Trait), Body Vigilance Scale (BVS), and Visceral Sensitivity Index (VSI) were assessed.

The association of moderate-to-vigorous and light-intensity physical activity on static balance in middle-aged and older-aged adults.

Background: Falls are the leading cause of injury among adults ≥ 65 years of age. Participation in physical activity (PA) is associated with improved balance, though it is impact in the middle-age population is not well understood.

Aim: The purpose of the current study was to examine the influence of PA intensity on static balance in middle-aged and older aged individuals.

Ordered Eating and Its Effects on Various Postprandial Health Markers: A Systematic Review.

Objective: Aberrations in glucose, insulin, and other postprandial (PP) markers are common in obesity and cardiometabolic disorders. One potentially simple lifestyle/dietary modification to manage these issues is to change the order in which foods are consumed within meals. Carbohydrate exerts the largest effect on PP glucose, and there is some evidence that ingesting dietary fat or protein before carbohydrate delays gastric emptying of carbohydrate and reduces PP glucose.

Occurrence and Impacts of Gastrointestinal Symptoms in Team-Sport Athletes: A Preliminary Survey.

Objectives: Although gastrointestinal (GI) symptoms are prevalent in endurance athletes, scant research has examined GI symptoms in team-sport athletes, their impacts, and explanatory factors. This study aimed to assess the prevalence and severity of GI symptoms in team-sport athletes and identify potential risk factors.

Design: An observational anonymous survey.

Thorn in Your Side or Thorn in Your Head? Anxiety and Stress as Correlates of Exercise-Related Transient Abdominal Pain.

Objectives: The etiology of exercise-related transient abdominal pain (ETAP) is not congruent among researchers notwithstanding numerous studies on the matter. No pursuit has sought to correlate ETAP with factors such as anxiety, stress, sleep dysfunction, and pain sensitivity that are linked to other gastrointestinal (GI) disturbances in athletes.

Design: Cross-sectional observational study involving an anonymous survey.

Does pain sensitivity correlate with gastrointestinal symptoms in runners? An observational survey study.

Objective: Heightened pain sensitivity is common in functional gut disorders, but no research has examined whether it corresponds to exercise-associated gastrointestinal (GI) symptoms. We sought to explore whether scores on a questionnaire of pain sensitivity would correlate with GI symptoms during running.

Design: This is a cross-sectional study.

Effects of Exercise Training on Resting Testosterone Concentrations in Insufficiently Active Men: A Systematic Review and Meta-Analysis.

Potter, NJ, Tomkinson, GR, Dufner, TJ, Walch, TJ, Roemmich, JN, Wilson, PB, and Fitzgerald, JS. Effects of exercise training on resting testosterone concentrations in insufficiently active men: a systematic review and meta-analysis. J Strength Cond Res 35(12): 3521-3528, 2021-The anabolic hormone testosterone plays a pivotal role in the healthy aging of men and tends to decline with age.

Associations of Urine Specific Gravity With Body Mass Index and Lean Body Mass at the Population Level: Implications for Hydration Monitoring.

Urine specific gravity (USG) thresholds are used in practice and research to determine hypohydration. However, some limited research has found that body size and body composition may impact USG, suggesting that fixed cutoffs may be insensitive. Cross-sectional data from 3,634 participants of the 2007-2008 National Health and Nutrition Examination Survey were analyzed.

Got Beer? A Systematic Review of Beer and Exercise.

Beer is used to socialize postexercise, celebrate sport victory, and commiserate postdefeat. Rich in polyphenols, beer has antioxidant effects when consumed in moderation, but its alcohol content may confer some negative effects. Despite beer's popularity, no review has explored its effects on exercise performance, recovery, and adaptation.

The association of physical activity on homocysteine in pregnant women.

Introduction: Women with high levels of physical activity have improved pregnancy, labor, and delivery outcomes related to cardiovascular health. Hyperhomocysteinemia, which predicts cardiovascular disease risk, is associated with maternal vascular complications during pregnancy, such as placental abruption and preeclampsia. However, studies are lacking on whether physical activity impacts homocysteine in pregnant women, pointing to a potential mechanism behind the improved cardiovascular health in women who exercise during pregnancy.

Stimulant Use as a Fatigue Countermeasure in Aviation.

Fatigue is a common problem in aviation. The identification of efficacious fatigue countermeasures is crucial for sustaining flight performance during fatigue-inducing operations. Stimulants are not recommended for consistent use, but are often implemented during flight operations with a high risk of fatigue.

Associations between sleep and in-race gastrointestinal symptoms: an observational study of running and triathlon race competitors.

Objective: It remains unstudied whether poor sleep is involved in the etiology of gastrointestinal (GI) problems in athletes.

Methods: Eighty-seven running and triathlon/duathlon race (>60 minutes) participants completed questionnaires to quantify the Sleep Problems Index-(SPI)-I and sleep parameters from the night before races. For GI symptoms, participants reported the severity (0-10 scale) of four upper and three lower symptoms during races.

Do Sex Differences in Physiology Confer a Female Advantage in Ultra-Endurance Sport?

Ultra-endurance has been defined as any exercise bout that exceeds 6 h. A number of exceptional, record-breaking performances by female athletes in ultra-endurance sport have roused speculation that they might be predisposed to success in such events. Indeed, while the male-to-female performance gap in traditional endurance sport (e.

Effects of high-carbohydrate versus mixed-macronutrient meals on female soccer physiology and performance.

Purpose: Athletes are often told to minimize intakes of fiber, fat, and protein in pre-competition meals to avoid gut distress, but this guidance is based on scant direct evidence. This study evaluated the physiological and perceptual effects of pre-competition mixed-macronutrient (MM) and high-carbohydrate (HCHO) meals in collegiate female soccer players.

Methods: Fifteen players participated in this randomized, investigator-blinded, crossover study involving two ~ 1000-kcal meals (HCHO and MM) consumed 4 h prior to 70-min scrimmages.

The Effects of Caffeine Mouth Rinsing on Exercise Performance: A Systematic Review.

Caffeine ingestion can improve performance across a variety of exercise modalities but can also elicit negative side effects in some individuals. Thus, there is a growing interest in the use of caffeine mouth rinse solutions to improve sport and exercise performance while minimizing caffeine's potentially adverse effects. Mouth rinse protocols involve swilling a solution within the oral cavity for a short time (e.

Anxiety may be a risk factor for experiencing gastrointestinal symptoms during endurance races: An observational study.

Scarce research has examined the links between stress, anxiety, and gastrointestinal (GI) symptoms during competition, despite that they are positively correlated in the general population. A total of 186 endurance athletes completed the Perceived Stress Scale (PSS)-14, Anxiety Sensitivity Index (ASI)-3, and State-Trait Inventory for Cognitive and Somatic Anxiety (STICSA) before races. Afterwards, they reported the severity of in-race GI symptoms.