Effects of long-term desmopressin treatment for nocturia in older people.

OBJECTIVES: Desmopressin improves nocturia frequency; however, reports on its long-term efficacy and safety are few, and concerns regarding its effect on body composition exist. We thus investigated the efficacy and safety of long-term desmopressin administration and its effect on body composition. METHODS: This retrospective study, conducted at Chikugo City Hospital between August 2020 and December 2022, involved 133 men (mean age, 77.7 years) with nocturnal and persistent nocturia, who were administered an initial dose of 50 µg desmopressin. Efficacy endpoints included nocturnal urinary frequency, nocturnal urinary volume, hours of undisturbed sleep, nocturnal polyuria index, initial nocturnal urinary volume, and daily urinary frequency in a frequency-volume chart (3 days), before treatment and at 1, 4, 12, 24, and 52 weeks after desmopressin administration. Additionally, the effects of desmopressin on body composition were examined, including blood-brain natriuretic peptide and a chest radiography, before and 52 weeks after administration. RESULTS: Treatment improved most efficacy endpoint evaluation parameters. Around 87.6% of patients showed improved symptoms after 52 weeks compared with those before treatment (score ≤ 3). The blood-brain natriuretic peptide level rose; however, cardiothoracic ratio was unchanged. CONCLUSION: Long-term administration of desmopressin is thus effective and safe in older people with nocturnal polyuria, with little effect on body composition.

Comparative effects of 8-week combined resistance exercise training and alternate-day calorie restriction on soluble epidermal growth factor receptor (sEGFR) and adipsin in obese men.

This study investigated the combined effects of resistance exercise training (RET) and alternate-day calorie restriction (ADCR) on body composition, insulin resistance (IR), insulin resistance-related biomarkers (adipokine adipsin and hepatokine soluble EFGR), and weight loss in obese men. The findings revealed that RET + ADCR induced the greatest reductions in body weight, body fat percentage, and waist-to-hip ratio (WHR) compared to RET and ADCR alone (p < 0.05). Additionally, RET + ADCR resulted in the most significant improvements in IR, as measured by HOMA-IR, and in circulating levels of adipsin and soluble EFGR (p < 0.05). These findings suggest that combining RET and ADCR may be a more effective strategy for improving metabolic health, including body composition, IR, and metabolic tissues' functions, in obese men than either intervention alone.

Assessment of Nutritional Intake in Patients with Kidney Failure Treated by Haemodialysis on Dialysis and Non-dialysis days.

INTRODUCTION/AIMS/OBJECTIVE: Inadequate nutritional intake in haemodialysis (HD) patients increases the risk of muscle wasting, nutrient deficiencies, leading to an increased risk of additional morbidity and mortality. We aimed to assess nutritional intake on the dialysis and non-dialysis day of patients established on HD. METHODS: We employed a two-day dietary record, one on the day of dialysis and one on the non-dialysis day, and then determined nutritional intake using the Nutritics software. Muscle strength was assessed by hand grip strength (HGS) and body composition determined using multifrequency bioelectrical impedance recorded post-dialysis. RESULTS: We recruited 51 established HD patients dialysing between May-July 2022, mean age 60±15 years, 52.9% male, and 51% diabetic. Only 25% achieved the calorie and protein intake recommended by Kidney Disease Outcomes Quality Initiative (KDOQI). Most patients had inadequate consumtion of fibre (96%), calcium (86%), iron (80%), zinc (82%), selenium (92%), folate (82%), vitamin A (88%), and (100%) vitamin D. On the other hand, the great majority followed the restriction guidelines for potassium (96%), phosphorus (86%), and sodium (84%), repectively. However, consumption was greater for potassium (P=0.007), phosphorus (P=0.015), and zinc (P=0.032) on non-dialysis vs dialysis days, but there was no difference in protein or calorie intake between days. CONCLUSION: Our results suggest that many of our HD patients do not achieve the recommended nutritional targets. Patient compliance with restricting sodium, potassium and phosphate limits protein and calorie intake. HD patients are at increased risk of sarcopenia, so failure to achieve dietary protein intake will further increase this risk.

Sarcopenic obesity in patients awaiting liver transplant: Unique challenges for nutritional recommendations.

Sarcopenic obesity increases the risk of mortality in patients with liver disease awaiting liver transplantation and in the post-transplant period. Nutrition recommendations for individuals with sarcopenia differ from recommendations for patients with obesity or sarcopenic obesity. While these nutrition guidelines have been established in non-cirrhotic patients, established guidelines for liver transplant candidates with sarcopenic obesity are lacking. In this paper, we review existing literature on sarcopenic obesity in patients with chronic liver disease and address opportunities to improve nutritional counseling in patients awaiting liver transplantation.

The Effect of Prenatal Docosahexaenoic Acid Supplementation on Offspring Fat Mass and Distribution at 24 Months Old.

Background: Excessive gestational weight gain (GWG) is related to increased offspring fat accrual, and increased fat mass (FM) is related to obesity development. Prenatal DHA supplementation has been linked to lower levels of offspring FM; however, conflicting data exist. Objectives: This study aimed to determine if there is a protective effect of prenatal DHA supplementation on offspring fat accrual and adipose tissue deposition at 24 mo in offspring born to females who gain excessive weight compared with nonexcessive weight during pregnancy. We also explored if the effect of DHA dose on FM differed by offspring sex. Methods: Infants born to females who participated in the Assessment of DHA on Reducing Early Preterm Birth randomized controlled trial (ADORE) were recruited. In ADORE, females were randomly assigned to either a high or low prenatal DHA supplement. Offspring body composition and adipose tissue distribution were measured using dual-energy x-ray absorptiometry (DXA). GWG was categorized as excessive or not excessive based on clinical guidelines. Results: For total FM, there was a significant main effect for the DHA dose (P = 0.03); however, the dose by GWG status was nonsignificant (P = 0.44). Therefore, a higher prenatal DHA dose was related to greater offspring FM (622.9 g greater) and unrelated to GWG status. When investigating a DHA dose by sex effect, a significant main effect for DHA dose (P = 0.01) was detected for central FM. However, no interaction was detected (P = 0.98), meaning that both boys and girls had greater central FM if their mother was assigned to the higher DHA dose. Conclusions: Greater prenatal DHA supplementation was associated with greater offspring FM and adipose tissue distribution at 24 mo. It will be important to understand if these effects persist into childhood.This trial was registered at clinicaltrials.gov as NCT03310983.

Insulin sensitivity, body composition and bone mineral density after testosterone treatment in transgender youth with and without prior GnRH agonist therapy.

Background: 1.8% of youth identify as transgender; a growing proportion are transgender male (female sex, male gender identity). Many receive gonadotropin releasing hormone agonist (GnRHa) therapy to suppress endogenous puberty and/or will start testosterone to induce secondary sex characteristics that align with gender identity. Objectives: To determine the effects of 12 months of testosterone on cardiometabolic health among transgender youth, including insulin sensitivity, body composition, and bone mineral density and whether changes in outcomes differ based on prior GnRHa treatment. Methods: Participants (n = 19, baseline age 15.0 ± 1.0 years) were examined prior to and 12 months after testosterone therapy in a longitudinal observational study. Fasted morning blood draw, a 2-hour 75-gram oral glucose tolerance test, body composition and bone mineral density (dual-energy X-ray absorptiometry) were assessed at baseline and 12 months. Insulin sensitivity was estimated by HOMA-IR and Matsuda index. Changes were compared with mixed linear regression models evaluating time (baseline, 12 months), group (GnRHa treatment yes/no), and their interaction. Results: In the entire cohort, fasted insulin decreased (median [25,75 %ile]: -3 [-5, 0] mIU/L, p = 0.044) and 2-hour glucose increased (mean ± standard deviation): +18.5 ± 28.9 mg/dL, p = 0.013 from baseline after 12 months of testosterone therapy. There were no significant changes in HOMA-IR (p = 0.062) or Matsuda index (p = 0.096), nor by GnRHa status. Absolute (+6.2 [4.7, 7.5] kg, p = 0.016) and percent fat-free mass increased (+7.3 [5.4, 9.1] %, p = 0.003) and percent fat mass declined (-7.4 [-9.3, 5.3]%, p = 0.005) for the entire cohort. There were time*group interactions for absolute (p = 0.0007) and percent fat-free mass (p = 0.033). There were time*group interactions for bone mineral content (p = 0.006). Conclusions: Twelve months of testosterone in transgender adolescents resulted in changes in body composition and bone mineral density, with baseline differences between the +/-GnRHa group and convergence after 12 months. There were no changes in insulin sensitivity over time or between groups.

Regional adiposity and insulin sensitivity - interactions with menopause and HIV in middle-aged Black African women.

OBJECTIVE: To explore depot-specific functional aspects of adipose tissue, examining the putative role for menopause and HIV status on insulin sensitivity (SI) and beta-cell function in Black South African women. METHODS: Women (n = 92) from the Middle-Aged Soweto Cohort, including premenopausal HIV-negative (n = 21); premenopausal women living with HIV (WLWH; n = 11); postmenopausal HIV-negative (n = 42); postmenopausal WLWH (n = 18) underwent the following tests: body composition (dual energy x-ray absorptiometry); fasting bloods for sex hormones, inflammation and adipokines; frequently sampled intravenous glucose tolerance test for SI and beta-cell function (disposition index, DI); abdominal (aSAT) and gluteal subcutaneous adipose tissue (gSAT) biopsies for cell size and mRNA expression of adipokines, inflammation, and estrogen receptors [ER]. RESULTS: Depot-specific associations between gene expression and insulin parameters did not differ by HIV or menopause status. Pooled analysis showed significant models for SI (P = 0.002) and DI (P = 0.003). Higher SI was associated with lower leptin and CD11c expression in aSAT and higher adiponectin in gSAT. Higher DI was associated with higher aSAT and gSAT expression of adiponectin, LPL, ERα, and PPARγ, and lower leptin in aSAT. WLWH had higher expression of adiponectin and lower expression of leptin in both aSAT (P = 0.002 and P = 0.005) and gSAT (P = 0.004 and P = 0.002), respectively, and a larger proportion of smaller cells in aSAT (P < 0.001). CONCLUSION: Insulin sensitivity and beta cell function were distinctively associated with aSAT and gSAT. While menopause did not influence these relationships, HIV had a significant effect on adipose tissue, characterised by variations in cell size distribution and transcript levels within the depots.

The Influence of Visceral Adiposity on Overall Survival: Exploring "Obesity Paradox" Among Hepatocellular Carcinoma Patients Who Receiving Immunotherapy.

Purpose: The impact of visceral adiposity on overall survival (OS) in hepatocellular carcinoma (HCC) receiving immunotherapy was unclear. We aimed to determine how visceral adiposity affected OS and explore the interrelationships between visceral adiposity, body mass index (BMI), and other body compositions. Patients and Methods: Data from three centers were retrospectively analyzed. Skeletal muscle index (SMI), skeletal muscle density (SMD), visceral adipose tissue index (VATI), and subcutaneous adipose tissue index (SATI) were used to define each body composition. The BMI subgroups included the underweight, the normal weight, and the obesity. The Log rank test compared survival curves calculated by the Kaplan-Meier method. The relationships between body compositions and BMI with OS were examined using Cox proportional risk regression models. Results: A total of 305 patients who met the criteria were included. Patients with low VATI had significantly worse OS (P = 0.001). The protections of VATI (P = 0.011) on OS were independent of covariates. However, after additional adjustment of SMI, the effect of VATI on OS disappeared (P = 0.146), but the effect of SMD on OS did not (P = 0.021). BMI has a significant U-shaped relationship with OS, and the effect of BMI on OS equally disappeared after additional adjustment by SMI. Conclusion: This study first demonstrated that high VATI and mid-level BMI were protective for the survival of patients with HCC receiving immunotherapy. Skeletal muscle status (including SMI and SMD) may be the better predictor for outcomes of patients with HCC receiving immunotherapy.

Transgender healthcare: metabolic outcomes and cardiovascular risk.

Transgender identity is often associated with gender dysphoria and minority stress. Gender-affirming hormone treatment (GAHT) includes masculinising or feminising treatment and is expected to be lifelong in most cases. Sex and sex hormones have a differential effect on metabolism and CVD in cisgender people, and sex hormone replacement in hypogonadism is associated with higher vascular risk, especially in ageing individuals. Using narrative review methods, we present evidence regarding metabolic and cardiovascular outcomes during GAHT and propose recommendations for follow-up and monitoring of metabolic and cardiovascular risk markers during GAHT. Available data show no increased risk for type 2 diabetes in transgender cohorts, but masculinising GAHT increases lean body mass and feminising GAHT is associated with higher fat mass and insulin resistance. The risk of CVD is increased in transgender cohorts, especially during feminising GAHT. Masculinising GAHT is associated with a more adverse lipid profile, higher haematocrit and increased BP, while feminising GAHT is associated with pro-coagulant changes and lower HDL-cholesterol. Assigned male sex at birth, higher age at initiation of GAHT and use of cyproterone acetate are separate risk factors for adverse CVD markers. Metabolic and CVD outcomes may improve during gender-affirming care due to a reduction in minority stress, improved lifestyle and closer surveillance leading to optimised preventive medication (e.g. statins). GAHT should be individualised according to individual risk factors (i.e. drug, dose and form of administration); furthermore, doctors need to discuss lifestyle and preventive medications in order to modify metabolic and CVD risk during GAHT. Follow-up programmes must address the usual cardiovascular risk markers but should consider that biological age and sex may influence individual risk profiling including mental health, lifestyle and novel cardiovascular risk markers during GAHT.

No Evidence for Cross-Sectional or Longitudinal Associations between Cognitive Flexibility Performances and Nutritional Status in a Cohort of Inpatients with Anorexia Nervosa.

BACKGROUND: According to the Cognitive-Interpersonal model of anorexia nervosa (AN), the combined influence of cognitive and socio-emotional difficulties would constitute vulnerability and maintaining factors. Poor cognitive flexibility is one of the endophenotypic candidates (i.e., a trait marker) of the disorder, but few studies have examined its association with illness symptom variations, notably weight status. The study aimed to evaluate the relationships between cognitive flexibility performances and nutritional status indices (BMI; body composition) at different times of the disorder. METHODS: Cross-sectional and longitudinal associations between cognitive flexibility (TAP 2.1) and nutritional status indices, along with anxious and depressive (HAD) and eating disorder (EDE-Q) symptomatology were investigated using univariate and multivariate analyses in a cohort of AN inpatients evaluated at hospital admission (N = 167) and discharge (N = 94). RESULTS: We found no or negligible associations between nutritional status and HAD or EDE-Q scores or cognitive flexibility performances, either cross-sectionally or longitudinally. Cognitive performances did not significantly differ between the AN subtypes. CONCLUSIONS: In agreement with the Cognitive-Interpersonal model of AN, cognitive flexibility is independent of nutritional status, as well as the AN subtype. It is also independent of the levels of anxious, depressive, or ED symptomatology. A new therapeutic approach targeting cognitive flexibility and intolerance to change could benefit severely emaciated people with AN, regardless of disease subtype and level of dysphoria.

Exploring Vegetarian and Omnivorous Approaches to Cardiovascular Risk and Body Composition.

The role of nutrition in preventing non-communicable diseases has been widely studied in recent years, with indications that non-animal-based diets might improve body composition and therefore bring multiple health benefits. For all of these reasons, the main purpose was to compare body composition and metabolic status between vegetarian and omnivorous individuals and relate these values with cardiovascular risk. The present analysis included 176 participants (61 vegetarians and 115 omnivores). Body composition was assessed using a dual-energy X-ray absorptiometry, biochemical parameters obtained from capillary blood, and the 10-year cardiovascular risk (10RCVD) calculated by the QRISK3 score. No statistical differences were found between groups regarding body composition. Concerning metabolic markers, vegetarian individuals showed reduced values of total cholesterol, LDL cholesterol, and non-HDL cholesterol (p < 0.05). There were no differences in 10RCVD between groups. In both diets, moderate correlations between groups were found for cardiovascular risk and visceral adipose tissue. Our results suggest that the vegetarian regimen might be associated with better cardiometabolic biomarkers and better cardiovascular health, although controversial with the body composition trends observed. In conclusion, the results suggest that cardiovascular risk appears to be more influenced by body composition, mainly fat tissue, over dietary patterns itself.

Efficacy of Pea Protein Supplementation in Combination with a Resistance Training Program on Muscle Performance in a Sedentary Adult Population: A Randomized, Comparator-Controlled, Parallel Clinical Trial.

Animal-sourced whey protein (WPr) is the most popular protein supplement among consumers and has been shown to improve muscle mass and strength. However, due to allergies, dietary restrictions/personal choices, and growing demand, alternative protein sources are warranted. Sedentary adults were randomized to pea protein (PPr) or WPr in combination with a weekly resistance training program for 84 days. Changes in whole-body muscle strength (WBMS) including handgrip, lower body, and upper body strength, body composition, and product perception were assessed. The safety outcomes included adverse events, vital signs, clinical chemistry, and hematology. There were no significant differences in the change in WBMS, muscle mass, or product perception and likability scores between the PPr and WPr groups. The participants supplemented with PPr had a 16.1% improvement in WBMS following 84 days of supplementation (p = 0.01), while those taking WPr had an improvement of 11.1% (p = 0.06). Both study products were safe and well-tolerated in the enrolled population. Eighty-four days of PPr supplementation resulted in improvements in strength and muscle mass comparable to WPr when combined with a resistance training program in a population of healthy sedentary adults. PPr may be considered as a viable alternative to animal-sourced WPr without sacrificing muscular gains and product enjoyment.

A Plea for Monitoring Serum Selenium Levels in Breast Cancer Patients: Selenium Deficiency Is Rare during the First Year of Therapy, and Selenium Supplementation Is Associated with Elevated Risk of Overdosing.

(1) Background: The role of selenium in cancer biology remains poorly understood. Our aim was to study the course of selenium serum levels and the use of selenium supplements during breast cancer therapy. (2) Methods: Serum selenium levels, clinical-pathological data, selenium supplementation, and lifestyle factors were monitored quarterly over one year. (3) Results: A total of 110 non-metastatic breast cancer patients were enrolled in the prospective observational "BEGYN-1" study. At baseline, 2.9% of patients were selenium-deficient (<50 ng/mL), 1.9% were overdosed (>120 ng/mL), and 6.4% received substitution. The median selenium level was 81.5 ng/mL and ranged between 78.7 and 84.5 ng/mL within the year. A total of 25.3% of the patients received supplementation, resulting in significantly higher selenium levels (p < 0.05). A total of 8.7-28.6% of the patients using supplements were overdosed. Selenium levels strongly correlated with mushroom consumption (p = 0.003), but no association was found with therapy or clinical characteristics. (4) Conclusions: Although selenium deficiency is rare, serum selenium levels should be assessed in breast cancer patients. Mushrooms and nuts should be preferred over supplements to correct selenium deficiency. Ruling out selenium deficiency helps prevent the risk of selenosis and avoid unnecessary, costly supplementation in patients who are often financially burdened due to their disease.

Effects of Short-Term Nighttime Carbohydrate Restriction Method on Exercise Performance and Fat Metabolism.

BACKGROUND: The sleep-low method has been proposed as a way to sleep in a low-glycogen state, increase the duration of low glycogen availability and sleep and temporarily restrict carbohydrates to improve exercise performance. However, long-term dietary restriction may induce mental stress in athletes. Therefore, if it can be shown that the effects of the sleep-low method can be achieved by restricting the carbohydrate intake at night (the nighttime carbohydrate restriction method), innovative methods could be developed to reduce weight in individuals with obesity and enhance athletes' performance with reduced stress and in a shorter duration when compared with those of previous studies. With this background, we conducted a study with the purpose of examining the intervention effects of a short-term intensive nighttime carbohydrate restriction method. METHODS: A total of 22 participants were recruited among university students participating in sports club activities. The participants were assigned at random to groups, including a nighttime carbohydrate restriction group of 11 participants (6 males, 5 females; age 22.3 ± 1.23) who started a carbohydrate-restricted diet and a group of 11 participants (5 males, 6 females; age 21.9 ± 7.9) who continued with their usual diet. The present study had a two-group parallel design. In the first week, no dietary restrictions were imposed on either group, and the participants consumed their own habitual diets. In the second week, the total amount of calories and carbohydrate intake measured in the first week were divided by seven days, and the average values were calculated. These were used as the daily calorie and carbohydrate intakes in the second week. Only the nighttime carbohydrate restriction group was prohibited from consuming carbohydrates after 4:00 p.m. During the two-week study period, all participants ran for one hour each day before breakfast at a heart rate of 65% of their maximum heart rate. RESULTS: The results obtained from young adults participating in sports showed significant differences in peak oxygen consumption (V·O2peak), work rate max, respiratory quotient (RQ), body weight and lean body mass after the intervention when compared with before the intervention in the nighttime carbohydrate restriction group (p < 0.05). CONCLUSIONS: Our findings suggest that the nighttime carbohydrate restriction method markedly improves fat metabolism even when performed for a short period. This method can be used to reduce body weight in individuals with obesity and enhance athletes' performance. However, it is important to consider the intake of nutrition other than carbohydrates.

Defining and Addressing Research Priorities in Cancer Cachexia through Transdisciplinary Collaboration.

For many patients, the cancer continuum includes a syndrome known as cancer-associated cachexia (CAC), which encompasses the unintended loss of body weight and muscle mass, and is often associated with fat loss, decreased appetite, lower tolerance and poorer response to treatment, poor quality of life, and reduced survival. Unfortunately, there are no effective therapeutic interventions to completely reverse cancer cachexia and no FDA-approved pharmacologic agents; hence, new approaches are urgently needed. In May of 2022, researchers and clinicians from Moffitt Cancer Center held an inaugural retreat on CAC that aimed to review the state of the science, identify knowledge gaps and research priorities, and foster transdisciplinary collaborative research projects. This review summarizes research priorities that emerged from the retreat, examples of ongoing collaborations, and opportunities to move science forward. The highest priorities identified include the need to (1) evaluate patient-reported outcome (PRO) measures obtained in clinical practice and assess their use in improving CAC-related outcomes; (2) identify biomarkers (imaging, molecular, and/or behavioral) and novel analytic approaches to accurately predict the early onset of CAC and its progression; and (3) develop and test interventions (pharmacologic, nutritional, exercise-based, and through mathematical modeling) to prevent CAC progression and improve associated symptoms and outcomes.

Association of body composition indicators with colorectal cancer: a hospital-based case-control study.

PURPOSE: Colorectal cancer (CRC) is a common malignancy that affects adults worldwide, causing a high disease burden. Few studies have examined the relationship between body composition (BC) measures and the prevalence of CRC. Our purpose was to investigate the relationship between pertinent BC indicators and CRC. METHODS: Bioelectrical impedance analysis, laboratory test results, face-to-face questionnaire investigation, and nutritional risk assessment (Nutritional Risk Screening 2002 and Patient-Generated Subjective Global Assessment) were used in this case-control study. Bioelectrical impedance analysis in the case group was performed prior to antitumor therapy/surgery. RESULTS: From June 2018 to January 2019, a total of 303 cases and 286 controls were included. The results showed that low body fat percentage (BFP) and high visceral adiposity index (VAI) groups had a higher risk of developing CRC in comparison to the normal BFP and normal VAI groups. The risk of CRC decreased with the increase of BFP. The group with a normal BC had a lower risk of developing CRC compared to those with a greater VAI and a lower BFP, as indicated by the results of the pairwise and total combinations of VAI, fat-free mass index (FFMI), and BFP. Additionally, FFMI and VAI had positive correlations with prealbumin, serum albumin, and nutritional risk scores. CONCLUSION: Low BFP and high VAI are associated with higher CRC risk. FFMI and VAI are positively correlated with prealbumin, serum albumin, and nutritional risk scores in CRC patients.

Physiological Adaptations to Progressive Endurance Exercise Training in Adult and Aged Rats: Insights from the Molecular Transducers of Physical Activity Consortium (MoTrPAC).

While regular physical activity is a cornerstone of health, wellness, and vitality, the impact of endurance exercise training on molecular signaling within and across tissues remains to be delineated. The Molecular Transducers of Physical Activity Consortium (MoTrPAC) was established to characterize molecular networks underlying the adaptive response to exercise. Here, we describe the endurance exercise training studies undertaken by the Preclinical Animal Sites Studies component of MoTrPAC, in which we sought to develop and implement a standardized endurance exercise protocol in a large cohort of rats. To this end, Adult (6-mo) and Aged (18-mo) female (n = 151) and male (n = 143) Fischer 344 rats were subjected to progressive treadmill training (5 d/wk, ∼70%-75% VO2max) for 1, 2, 4, or 8 wk; sedentary rats were studied as the control group. A total of 18 solid tissues, as well as blood, plasma, and feces, were collected to establish a publicly accessible biorepository and for extensive omics-based analyses by MoTrPAC. Treadmill training was highly effective, with robust improvements in skeletal muscle citrate synthase activity in as little as 1-2 wk and improvements in maximum run speed and maximal oxygen uptake by 4-8 wk. For body mass and composition, notable age- and sex-dependent responses were observed. This work in mature, treadmill-trained rats represents the most comprehensive and publicly accessible tissue biorepository, to date, and provides an unprecedented resource for studying temporal-, sex-, and age-specific responses to endurance exercise training in a preclinical rat model.