Compensatory eating behaviors in male and female rats in response to exercise training

Thermoneutral-housed rats demonstrate impaired perivascular adipose tissue and vascular crosstalk

OBJECTIVE

Vascular pathology, characterized by impaired vasoreactivity and mitochondrial respiration, differs between the sexes. Housing rats under thermoneutral (TN) conditions causes vascular dysfunction and perturbed metabolism. We hypothesized that thoracic perivascular adipose tissue (tPVAT), a vasoregulatory adipose depot known to have a brown adipose tissue (BAT) phenotype, remodels to a mainly white adipose (WAT) phenotype in rats housed at TN, driving diminished vasoreactivity in a sex-dependent manner.

METHODS

Male and female Wistar rats were housed at either room temperature (RT) or TN. We measured changes in tPVAT morphology, vasoreactivity in vessels with intact tPVAT or transferred to tPVAT of the oppositely-housed animal, vessel stiffness, vessel mitochondrial respiration and cellular signaling.

RESULTS

Remodeling of tPVAT was observed in rats housed at TN; animals in this environment showed tPVAT whitening and displayed diminished aortae vasodilation ( P  < 0.05), different between the sexes. Juxtaposing tPVAT from RT rats onto aortae from TN rats in females corrected vasodilation ( P  < 0.05); this did not occur in males. In aortae of all animals housed at TN, mitochondrial respiration was significantly diminished in lipid substrate experiments ( P  < 0.05), and there was significantly less expression of phosphorylated endothelial nitric oxide synthase (peNOS) ( P  < 0.001).

CONCLUSIONS

These data are consistent with TN-induced remodeling of tPVAT, notably associated with sex-specific blunting of vasoreactivity, diminished mitochondrial respiration, and altered cellular signaling.

Gradual increase in energy intake over 8 weeks with voluntary wheel running limits body weight change in male rats

The influence of appetite and energy intake (EI) on energy compensation in response to chronic exercise remains poorly understood. This study examined the temporal impact of habitual exercise on EI and the homeostatic appetite regulators that influence energy compensation. Twelve-week-old male Sprague Dawley rats (n 30) fed an AIN-93M diet were randomised into one of three groups: (1) sedentary control (SED); (2) voluntary wheel exercise (EX) and (3) sedentary, weight-matched to aerobic exercise (SED-WM) for 8 weeks. Measures of EI, body weight and adiposity were assessed. Appetite-regulating hormones acyl ghrelin, active glucagon-like peptide (GLP)-1, leptin and insulin were measured in response to an oral glucose tolerance test. Rats with running wheels completed an average of 192 km over 8 weeks. While EI was initially reduced in EX, EI gradually increased with exercise training after week 1 (P < 0·05). Body weight was lower in EX relative to SED from weeks 3 to 5 but did not differ at the end of the study. Fat mass and long-term satiety hormones leptin and insulin were lower in EX (P < 0·05). No differences were observed in concentrations of the satiety hormone active GLP-1 or the orexigenic hormone acyl ghrelin. Short-term homeostatic regulators of appetite do not appear to be altered with exercise training. The reduction in adiposity and associated decrease in tonic satiety hormones leptin and insulin are likely contributors to the coupling of energy expenditure with EI over time with voluntary exercise.

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.

Exercise Rescues Obesogenic-Related Genes in the Female Hypothalamic Arcuate Nucleus: A Potential Role of miR-211 Modulation

Obesity is a major public health concern that is associated with negative health outcomes. Exercise and dietary restriction are commonly recommended to prevent or combat obesity. This study investigates how voluntary exercise mitigates abnormal gene expression in the hypothalamic arcuate nucleus (ARC) of diet-induced obese (DIO) rats. Using a transcriptomic approach, novel genes in the ARC affected by voluntary wheel running were assessed alongside physiology, pharmacology, and bioinformatics analysis to evaluate the role of miR-211 in reversing obesity. Exercise curbed weight gain and fat mass, and restored ARC gene expression. High-fat diet (HFD) consumption can dysregulate satiety/hunger mechanisms in the ARC. Transcriptional clusters revealed that running altered gene expression patterns, including inflammation and cellular structure genes. To uncover regulatory mechanisms governing gene expression in DIO attenuation, we explored miR-211, which is implicated in systemic inflammation. Exercise ameliorated DIO overexpression of miR-211, demonstrating its pivotal role in regulating inflammation in the ARC. Further, in vivo central administration of miR-211-mimic affected the expression of immunity and cell cycle-related genes. By cross-referencing exercise-affected and miR-211-regulated genes, potential candidates for obesity reduction through exercise were identified. This research suggests that exercise may rescue obesity through gene expression changes mediated partially through miR-211.

Perivascular adipose tissue remodeling impairs vasoreactivity in thermoneutral-housed rats

Objective

Vascular pathology, characterized by impaired vasoreactivity and mitochondrial respiration, differs between the sexes. Housing rats under thermoneutral (TN) conditions causes vascular dysfunction and perturbed metabolism. We hypothesized that perivascular adipose tissue (PVAT), a vasoregulatory adipose depot with brown adipose tissue (BAT) phenotype, remodels to a white adipose (WAT) phenotype in rats housed at TN, driving diminished vasoreactivity in a sex-dependent manner.

Methods

Male and female Wistar rats were housed at either room temperature (RT) or TN. Endpoints included changes in PVAT morphology, vasoreactivity in vessels with intact PVAT or transferred to PVAT of the oppositely-housed animal, vessel stiffness, vessel mitochondrial respiration and cellular signaling.

Results

Remodeling of PVAT was observed in rats housed at TN; animals in this environment showed PVAT whitening and displayed diminished aortae vasodilation (p<0.05), different between the sexes. Juxtaposing PVAT from RT rats onto aortae from TN rats in females corrected vasodilation (p<0.05); this did not occur in males. In aortae of all animals housed at TN, mitochondrial respiration was significantly diminished in lipid substrate experiments (p<0.05), and there was significantly less expression of peNOS (p<0.001).

Conclusions

These data are consistent with TN-induced remodeling of PVAT, notably associated with sex-specific blunting of vasoreactivity, diminished mitochondrial respiration, and altered cellular signaling.

Impact of Calorie-Restricted Cafeteria Diet and Treadmill Exercise on Sweet Taste in Diet-Induced Obese Female and Male Rats

The goal of the present study was to evaluate the sweet taste function in obese rats fed with a 30% calorie-restricted cafeteria diet (CAFR) and/or subjected to moderate treadmill exercise (12-17 m/min, 35 min, 5 days per week) for 9 weeks. A two-bottle preference test, a taste reactivity test, and a brief-access licking test were carried out when animals were aged 21 weeks; biometric and metabolic parameters were also measured along the interventions. Two separate experiments for females and males were performed. Behaviorally, CAF diet decreased sucrose intake and preference, as well as perceived palatability, in both sexes and decreased hedonic responses in males. Compared to the CAF diet, CAFR exerted a corrective effect on sweet taste variables in females by increasing sucrose intake in the preference test and licking responses, while exercise decreased sucrose intake in both sexes and licking responses in females. As expected, CAF diet increased body weight and Lee index and worsened the metabolic profile in both sexes, whereas CAFR diet ameliorated these effects mainly in females. Exercise had no noticeable effects on these parameters. We conclude that CAF diet might diminish appetitive behavior toward sucrose in both sexes, and that this effect could be partially reverted by CAFR diet in females only, while exercise might exert protective effects against overconsumption of sucrose in both sexes.

Restricted cafeteria feeding and treadmill exercise improved body composition, metabolic profile and exploratory behavior in obese male rats

The aim of this study was to evaluate, in male Long-Evans rats, whether a restricted-cafeteria diet (CAFR), based on a 30% calorie restriction vs continuous ad libitum cafeteria (CAF) fed animals, administered alone or in combination with moderate treadmill exercise (12 m/min, 35 min, 5 days/week for 8 weeks), was able to ameliorate obesity and the associated risk factors induced by CAF feeding for 18 weeks and to examine the changes in circadian locomotor activity, hypothalamic-pituitary-adrenal (HPA) axis functionality, and stress response elicited by this dietary pattern. In addition to the expected increase in body weight and adiposity, and the development of metabolic dysregulations compatible with Metabolic Syndrome, CAF intake resulted in a sedentary profile assessed by the home-cage activity test, reduced baseline HPA axis activity through decreased corticosterone levels, and boosted exploratory behavior. Both CAFR alone and in combination with exercise reduced abdominal adiposity and hypercholesterolemia compared to CAF. Exercise increased baseline locomotor activity in the home-cage in all dietary groups, boosted exploratory behavior in STD and CAF, partially decreased anxiety-like behavior in CAF and CAFR, but did not affect HPA axis-related parameters.

Effects of 12 weeks of aerobic exercise combined with resistance training on neurocognitive performance in obese women

Background/Objectives

To the best of our knowledge, there have been no previous studies conducted on the long-term effects of an exercise intervention on deficits in inhibitory control in obese individuals. The aim of this study was thus to examine the effect of 12 weeks of a combination of aerobic and resistance exercise on behavioral and cognitive electrophysiological performance involving cognitive interference inhibition in obese individuals.

Methods

Thirty-two qualified healthy obese women were randomly divided into either an exercise group (EG, age: 34.76 ± 5.52 years old; BMI: 29.35 ± 3.52 kg/m2) or a control group (CG, age: 33.84 ± 7.05 years old; BMI: 29.61 ± 4.31 kg/m2). All participants performed the Stroop task, with electrophysiological signals being collected simultaneously before and after a 12-week intervention. The estimated V̇O2max, muscular strength, and body fat percentage (measured with dual-energy X-ray absorptiometry) were also assessed within one week before and after the intervention. Participants in the EG group engaged in 30 min of moderate-intensity aerobic exercise combined with resistance exercise, 5 sessions per week for 12 weeks, while the participants in the CG group maintained their regular lifestyle without engaging in any type of exercise.

Results

The results revealed that although a 12-week exercise intervention did not enhance the behavioral indices [e.g., accuracy rates (ARs) and reaction times (RTs)] in the EG group, significantly shorter N2 and P3 latencies and greater P2 and P3 amplitudes were observed. Furthermore, the fat percentage distribution (e.g. total body fat %, trunk fat %, and leg fat %) and level of physical fitness (e.g. estimated V̇O2max and muscular strength) in the EG group were significantly improved. The changes prior to and after the intervention in the P3 amplitude and trunk fat percentage were significantly negatively correlated in the EG group (r = -0.521, p = 0.039).

Conclusions

These findings suggested that 12 weeks of aerobic exercise combined with resistance exercise in obese women affects cognitive function broadly, but not specifically in terms of inhibitory control. The percentage of decreased trunk fat may play a potential facilitating role in inhibition processing in obesity.

Sex Differences Distinctly Impact High-Fat Diet-Induced Immune Dysfunction in Wistar Rats

BACKGROUND

Immune function is altered during obesity. Moreover, males and females across different species demonstrate distinct susceptibility to several diseases. However, less is known regarding the interplay between high-fat diet (HFD) and sex in the context of immune function.

OBJECTIVES

The objective was to determine sex differences on immune function in response to an HFD compared with a control low-fat diet (LFD) in Wistar rats.

METHODS

At 5 wk of age, male and female Wistar rats were randomly assigned to 1 of 2 diets for 9 wk: ad libitum control LFD (20 kcal% fat, 53 kcal% carbohydrate, and 27 kcal% protein) or HFD (50 kcal% fat, 23 kcal% carbohydrate, and 27 kcal% protein). At 13 wk of age, rats were killed and splenocytes were isolated. Immune cell subsets were determined by flow cytometry. Immune cell function was determined by measuring the ex vivo cytokine production following stimulation with mitogens. Two-factor ANOVA was used to assess the main effect of sex, diet, and their interaction.

RESULTS

Males gained more weight than females (410 ± 46 vs. 219 ± 45 g), independently of diet (P-sex < 0.01). The HFD led to a lower production of IL-2 while increasing the production of IL-10 (both P-diet ≤ 0.05), independently of sex. HFD-fed females had increased production of cytokines (IL-2 and IL-6) after stimulation with phorbol 12-myristate 13-acetate plus ionomycin (PMA+I), as well as a higher T-helper (Th) 1:Th2 balance compared with HFD-fed males (all P < 0.05). Males fed the HFD had significantly lower production of IL-2 upon stimulation compared with all other groups.

CONCLUSIONS

Female Wistar rats developed a milder obesity phenotype and maintained enhanced cytokine production compared with males fed the HFD. Sex differences modulate immune function in the context of high-fat feeding and it should be considered in research design to establish personalized health-related recommendations.

Diets Containing Egg or Whey Protein and Inulin Fiber Improve Energy Balance and Modulate Gut Microbiota in Exercising Obese Rats

SCOPE

Dietary protein, prebiotic fiber and exercise individually have been shown to aid in weight loss; however less is known of their combined effects on energy balance. We determined the effects of diets high in protein and fiber, with exercise, on energy balance, hormones and gut microbiota.

METHODS AND RESULTS

Obese male rats were fed high-fat diets with high protein and fiber contents from egg protein and cellulose, egg protein and inulin, whey protein and cellulose, or whey protein and inulin, together with treadmill exercise. We found that inulin enriched diets decreased energy intake and respiratory quotient, increased energy expenditure, and upregulated transcripts for cholecystokinin (CCK), peptide YY and proglucagon in distal gut. Notably, CCK1-receptor blockade attenuated the hypophagic effects of diets and in particular whey-inulin diet, and β-adrenergic blockade reduced energy expenditure across all diets. Egg-cellulose, egg-inulin and whey-inulin diets decreased weight gain, adiposity, hepatic lipidosis and decreased lipogenic transcripts, improved glycemic control and up-regulated hepatic glucose metabolism transcripts, and decreased plasma insulin and leptin. Importantly, diet was linked to altered gut microbial composition and plasma metabolomics, and a subset of predicted metagenome pathways and plasma metabolites significantly correlated, with plasma butyric acid the most strongly associated to metagenome function.

CONCLUSION

Combination of dietary egg or whey protein with inulin and exercise improved energy balance, glucose metabolism, upregulated anorectic hormones, and selectively modulated gut microbiota and plasma metabolites. This article is protected by copyright. All rights reserved.

Effects of Simultaneous Exposure to a Western Diet and Wheel-Running Training on Brain Energy Metabolism in Female Rats

BACKGROUND

In the pathogenesis of central nervous system disorders (e.g., neurodegenerative), an important role is attributed to an unhealthy lifestyle affecting brain energy metabolism. Physical activity in the prevention and treatment of lifestyle-related diseases is getting increasing attention.

METHODS

We performed a series of assessments in adult female Long Evans rats subjected to 6 weeks of Western diet feeding and wheel-running training. A control group of lean rats was fed with a standard diet. In all experimental groups, we measured physiological parameters (animal weights, body composition, serum metabolic parameters). We assessed the impact of simultaneous exposure to a Western diet and wheel-running on the cerebrocortical protein expression (global proteomic profiling), and in the second part of the experiment, we measured the cortical levels of protein related to brain metabolism (Western blot).

RESULTS

Western diet led to an obese phenotype and induced changes in the serum metabolic parameters. Wheel-running did not reduce animal weights or fat mass but significantly decreased serum glucose level. The global proteome analysis revealed that the altered proteins were functionally annotated as they were involved mostly in metabolic pathways. Western blot analysis showed the downregulation of the mitochondrial protein-Acyl-CoA dehydrogenase family member 9, hexokinase 1 (HK1)-enzyme involved in principal glucose metabolism pathways and monocarboxylate transporter 2 (MCT2). Wheel-running reversed this decline in the cortical levels of HK1 and MCT2.

CONCLUSION

The cerebrocortical proteome is affected by a combination of physical activity and Western diet in female rats. An analysis of the cortical proteins involved in brain energy metabolism provides a valuable basis for the deeper investigation of changes in the brain structure and function induced by simultaneous exposure to a Western diet and physical activity.

The effects of acute exercise on appetite and energy intake in men and women

PURPOSE

To compare energy intake (EI) and appetite regulation responses between men and women following acute bouts of aerobic (AEx), resistance exercise (REx), and a sedentary control (CON).

METHODS

Men and women (n = 24; 50% male) with overweight/obesity, matched on age (32.3 ± 2 vs. 36.8 ± 2 yrs, p = 0.14) and BMI (28.1 ± 1.2 vs 29.0 ± 1.5 kg/m2, p = 0.64) completed 3 conditions: 1) AEx (65-70% of age-predicted maximum heart rate for 45 min); 2) REx (1-set to failure on 12 exercises); and 3) CON. Each condition was initiated in the post-prandial state (35 min following consumption of a standardized breakfast). Appetite (visual analog scale for hunger, satiety, and prospective food consumption [PFC]) and hormones (ghrelin, PYY, and GLP-1) were measured in the fasted state and every 30 min post-prandially for 3 h. Post-exercise ad libitum EI at the lunch meal was also measured.

RESULTS

Men reported higher levels of hunger compared to women across all study conditions (AEx: Men: 7815.00 ± 368.3; Women: 5428.50 ± 440.0 mm x 180 min; p = 0.025; REx: Men: 7110.00 ± 548.4; Women: 6086.25 ± 482.9 mm x 180 min; p = 0.427; CON: Men: 8315.00 ± 429.8; Women: 5311.25 ± 543.1 mm x 180 min; p = 0.021) and consumed a greater absolute caloric load than women at the ad libitum lunch meal (AEx: Men: 1021.6 ± 105.4; Women: 851.7 ± 70.5 kcals; p = 0.20; REx: Men: 1114.7 ± 104.0; Women: 867.7 ± 76.4 kcals; p = 0.07; CON: Men: 1087.0 ± 98.8; Women: 800.5 ± 102.3 kcals; p = 0.06). However, when adjusted for relative energy needs, there was no difference in relative ad libitum EI observed between men and women. No differences in Area Under the Curve for Satiety, PFC, ghrelin, PYY, and GLP-1 were noted between men and women following acute exercise (all p > 0.05).

CONCLUSIONS

These data suggest that women report lower ratings of appetite following an acute bout of exercise or sedentary time when compared to men, yet have similar relative EI. Future work is needed to examine whether sex-based differences in appetite regulation and EI are present with chronic exercise of differing modalities.

Rolling out physical exercise and energy homeostasis: Focus on hypothalamic circuitries

Energy balance is the fine regulation of energy expenditure and energy intake. Negative energy balance causes body weight loss, while positive energy balance promotes weight gain. Modern societies offer a maladapted way of life, where easy access to palatable foods and the lack of opportunities to perform physical activity are considered the roots of the obesity pandemic. Physical exercise increases energy expenditure and, consequently, is supposed to promote weight loss. Paradoxically, physical exercise acutely drives anorexigenic-like effects, but the mechanisms are still poorly understood. Using an evolutionary background, this review aims to highlight the potential involvement of the melanocortin system and other hypothalamic neural circuitries regulating energy balance during and after physical exercise. The physiological significance of these changes will be explored, and possible signalling agents will be addressed. The knowledge discussed here might be important for clarifying obesity aetiology as well as new therapeutic approaches for body weight loss.

New Horizon: Exercise and a Focus on Tissue-Brain Crosstalk

The world population is aging, leading to increased rates of neurodegenerative disorders. Exercise has countless health benefits and has consistently been shown to improve brain health and cognitive function. The purpose of this review is to provide an overview of exercise-induced adaptations in the brain with a focus on crosstalk between peripheral tissues and the brain. We highlight recent investigations into exercise-induced circulating factors, or exerkines, including irisin, cathepsin B, GPLD1, and ketones and the mechanisms mediating their effects in the brain.

An Omega-3-rich Anti-inflammatory Diet Improved Widespread Allodynia and Worsened Metabolic Outcomes in Adult Mice Exposed to Neonatal Maternal Separation

Inflammation plays a key role in the progression and maintenance of chronic pain, which impacts the lives of millions of Americans. Despite growing evidence that chronic pain can be improved by treating underlying inflammation, successful treatments are lacking and pharmaceutical interventions are limited due to drug side effects. Here we are testing whether a 'healthy human' diet (HHD), with or without anti-inflammatory components (HHAID), improves pain-like behaviors in a preclinical model of chronic widespread hypersensitivity induced by neonatal maternal separation (NMS). The HHD and HHAID are isocaloric and macronutrient-matched, have a low glycemic index, and fat content (35 kcal%) that is high in omega-3 fatty acids, while only the HHAID includes a combination of key anti-inflammatory compounds, at clinically relevant doses. Mice on these diets were compared to mice on a control diet with a macronutrient composition commonly used in rodents (20% protein, 70% carbohydrate, 10% fat). Our results demonstrate a benefit of the HHAID on pain-like behaviors in both male and female mice, despite increased caloric intake, adiposity, and weight gain. In female mice, HHAID specifically increased measures of metabolic syndrome and inflammation compared to the HHD and control diet groups. Male mice were susceptible to worsening metabolic measures on both the HHAID and HHD. This work highlights important sexual dimorphic outcomes related to early life stress exposure and dietary interventions, as well as a potential disconnect between improvements in pain-like behaviors and metabolic measures.

Endurance Is Improved in Female Rats After Living High-Training High Despite Alterations in Skeletal Muscle

Altitude camps are used during the preparation of endurance athletes to improve performance based on the stimulation of erythropoiesis by living at high altitude. In addition to such whole-body adaptations, studies have suggested that high-altitude training increases mitochondrial mass, but this has been challenged by later studies. Here, we hypothesized that living and training at high altitude (LHTH) improves mitochondrial efficiency and/or substrate utilization. Female rats were exposed and trained in hypoxia (simulated 3,200 m) for 5 weeks (LHTH) and compared to sedentary rats living in hypoxia (LH) or normoxia (LL) or those that trained in normoxia (LLTL). Maximal aerobic velocity (MAV) improved with training, independently of hypoxia, whereas the time to exhaustion, performed at 65% of MAV, increased both with training (P = 0.009) and hypoxia (P = 0.015), with an additive effect of the two conditions. The distance run was 7.98 ± 0.57 km in LHTH vs. 6.94 ± 0.51 in LLTL (+15%, ns). The hematocrit increased >20% with hypoxia (P < 0.001). The increases in mitochondrial mass and maximal oxidative capacity with endurance training were blunted by combination with hypoxia (−30% for citrate synthase, P < 0.01, and −23% for Vmax _glut−succ, P < 0.001 between LHTH and LLTL). A similar reduction between the LHTH and LLTL groups was found for maximal respiration with pyruvate (−29%, P < 0.001), for acceptor-control ratio (−36%, hypoxia effect, P < 0.001), and for creatine kinase efficiency (−48%, P < 0.01). 3-hydroxyl acyl coenzyme A dehydrogenase was not altered by hypoxia, whereas maximal respiration with Palmitoyl-CoA specifically decreased. Overall, our results show that mitochondrial adaptations are not involved in the improvement of submaximal aerobic performance after LHTH, suggesting that the benefits of altitude camps in females relies essentially on other factors, such as the transitory elevation of hematocrit, and should be planned a few weeks before competition and not several months.

Barriers in translating preclinical rodent exercise metabolism findings to human health

Physical inactivity and low aerobic capacity are primary drivers of chronic disease pathophysiology and are independently associated with all-cause mortality. Conversely, increased physical activity and exercise are central to metabolic disease prevention and longevity. Although these relationships are well characterized in the literature, what remains incompletely understood are the mechanisms by which physical activity/exercise prevents disease. Given methodological constraints of clinical research, investigators must often rely on preclinical rodent models to investigate these potential underlying mechanisms. However, there are several key barriers to applying exercise metabolism findings from rodent models to human health. These barriers include housing temperature, nutrient metabolism, exercise modality, exercise testing, and sex differences. Increased awareness and understanding of these barriers will enhance the ability to impact human health through more appropriate experimental design and interpretation of data within the context of these factors.

Effects of Acute Aerobic Exercise Combined with Resistance Exercise on Neurocognitive Performance in Obese Women

To the best of the author’s knowledge, there have been no previous studies conducted on the effects of a combination of acute aerobic and resistance exercise on deficit of inhibitory control in obese individuals. The aim of this study was, thus, to examine the effect of a single bout of such an exercise mode on behavioral and cognitive electrophysiological performance involving cognitive interference inhibition in obese women. After the estimated VO₂max and percentage fat (measured with dual-energy X-ray absorptiometry (Hologic, Bedford, MA, USA) were assessed, 32 sedentary obese female adults were randomly assigned to an exercise group (EG) and a control group (CG), with their behavioral performance being recorded with concomitant electrophysiological signals when performing a Stroop task. Then, the EG engaged in 30 min of moderate-intensity aerobic exercise combined with resistance exercise, and the CG rested for a similar duration of time without engaging in any type of exercise. After the interventions, the neurocognitive performance was measured again in the two groups. The results revealed that although acute exercise did not enhance the behavioral indices (e.g., accuracy rates (ARs) and reaction times (RTs)), cognitive electrophysiological signals were improved (e.g., shorter N2 and P3 latencies, smaller N2 amplitudes, and greater P3 amplitudes) in the Stroop task after the exercise intervention in the EG. The findings indicated that a combination of acute moderate-intensity aerobic and resistance exercise may improve the neurophysiological inhibitory control performance of obese women.

Sex-Dependent Wheel Running Effects on High Fat Diet Preference, Metabolic Outcomes, and Performance on the Barnes Maze in Rats

Excessive and prolonged intake of highly palatable, high fat (HF) foods contributes to the pathogenesis of obesity, metabolic syndrome, and cognitive impairment. Exercise can restore energy homeostasis and suppress HF diet preference in rats. However, it is unclear if exercise confers similar protection against the detrimental outcomes associated with a chronic HF diet preference and feeding in both sexes. We used our wheel running (WR) and two-diet choice (chow vs. HF) paradigm to investigate the efficacy of exercise in reversing HF diet-associated metabolic and cognitive dysregulation in rats, hypothesizing that beneficial effects of exercise would be more pronounced in males. All WR rats showed HF diet avoidance upon running initiation, and males, but not females, had a prolonged reduction in HF diet preference. Moreover, exercise only improved glucose tolerance and insulin profile in males. Compared to sedentary controls, all WR rats improved learning to escape on the Barnes maze. Only WR females increased errors made during subsequent reversal learning trials, indicating a sex-dependent effect of exercise on behavioral flexibility. Taken together, our results suggest that exercise is more effective at attenuating HF-associated metabolic deficits in males, and highlights the importance of developing sex-specific treatment interventions for obesity and cognitive dysfunction.