Preventing Exertional Heat Stroke in Football: Time for a Paradigm Shift.

CONTEXT: Among American sports, football has the highest incidence of exertional heat stroke (EHS), despite decades of prevention strategies. Based on recent reports, 100% of high school and college EHS football fatalities occur during conditioning sessions. Linemen are the at-risk population, constituting 97% of football EHS deaths. Linemen heat up faster and cool down slower than other players. EVIDENCE ACQUISITION: Case series were identified from organized, supervised football at the youth, high school, and collegiate levels and compiled in the National Registry of Catastrophic Sports Injuries. Sources for event occurrence were media reports and newspaper clippings, autopsy reports, certificates of death, school-sponsored investigations, and published medical literature. Articles were identified through PubMed with search terms "football," "exertional heat stroke," and "prevention." STUDY DESIGN: Clinical review. LEVEL OF EVIDENCE: Level 5. RESULTS: Football EHS is tied to (1) high-intensity drills and conditioning that is not specific to individual player positions, (2) physical exertion as punishment; (3) failure to modify physical activity for high heat and humidity, (4) failure to recognize early signs and symptoms of EHS, and (5) death when cooling is delayed. CONCLUSION: To prevent football EHS, (1) all training and conditioning should be position specific; (2) physical activity should be modified per the heat load; (3) understand that some players have a "do-or-die" mentality that supersedes their personal safety; (4) never use physical exertion as punishment; (5) eliminate conditioning tests, serial sprints, and any reckless drills that are inappropriate for linemen; and (6) consider air-conditioned venues for linemen during hot practices. To prevent EHS, train linemen based on game demands. STRENGTH-OF-RECOMMENDATION TAXONOMY: n/a.

Identification of sleep and circadian alternative polyadenylation sites associated with APA-linked human brain disorders.

Sleep and circadian rhythm disruptions are comorbid features of many pathologies and can negatively influence numerous health conditions, including degenerative diseases, metabolic illnesses, cancer, and various neurological disorders. Genetic association studies linking sleep and circadian disturbances with disease susceptibility have mainly focused on changes in gene expression due to mutations, such as single-nucleotide polymorphisms. Thus, associations between sleep and/or circadian rhythm and alternative polyadenylation (APA), particularly in the context of other health challenges, are largely undescribed. APA is a process that generates various transcript isoforms from the same gene, resulting in effects on mRNA translation, stability, localization, and subsequent function. Here, we have identified unique APAs in rat brain that exhibit time-of-day-dependent oscillations in expression as well as APAs that are altered by sleep deprivation and the subsequent recovery period. Genes affected by APA usage include Mapt/Tau, Ntrk2, Homer1A, Sin3band Sorl. Sorl1 has two APAs which cycle with a 24 h period, one additional APA cycles with a 12 h period and one more that is reduced during recovery sleep. Finally, we compared sleep- or circadian-associated APAs with recently described APA-linked brain disorder susceptibility genes and found 46 genes in common.

Cannabis Sativa targets mediobasal hypothalamic neurons to stimulate appetite.

The neurobiological mechanisms that regulate the appetite-stimulatory properties of cannabis sativa are unresolved. This work examined the hypothesis that cannabinoid-1 receptor (CB1R) expressing neurons in the mediobasal hypothalamus (MBH) regulate increased appetite following cannabis vapor inhalation. Here we utilized a paradigm where vaporized cannabis plant matter was administered passively to rodents. Initial studies in rats characterized meal patterns and operant responding for palatable food following exposure to air or vapor cannabis. Studies conducted in mice used a combination of in vivo optical imaging, electrophysiology and chemogenetic manipulations to determine the importance of MBH neurons for cannabis-induced feeding behavior. Our data indicate that cannabis vapor increased meal frequency and food seeking behavior without altering locomotor activity. Importantly, we observed augmented MBH activity within distinct neuronal populations when mice anticipated or consumed food. Mechanistic experiments demonstrated that pharmacological activation of CB1R attenuated inhibitory synaptic tone onto hunger promoting Agouti Related Peptide (AgRP) neurons within the MBH. Lastly, chemogenetic inhibition of AgRP neurons attenuated the appetite promoting effects of cannabis vapor. Based on these results, we conclude that MBH neurons contribute to the appetite stimulatory properties of inhaled cannabis.

Amylin Modulates a Ventral Tegmental Area-to-Medial Prefrontal Cortex Circuit to Suppress Food Intake and Impulsive Food-Directed Behavior.

BACKGROUND: A better understanding of the neural mechanisms regulating impaired satiety to palatable foods is essential to treat hyperphagia linked with obesity. The satiation hormone amylin signals centrally at multiple nuclei including the ventral tegmental area (VTA). VTA-to-medial prefrontal cortex (mPFC) projections encode food reward information to influence behaviors including impulsivity. We hypothesized that modulation of VTA-to-mPFC neurons underlies amylin-mediated decreases in palatable food-motivated behaviors. METHODS: We used a variety of pharmacological, behavioral, genetic, and viral approaches (n = 4-16/experiment) to investigate the anatomical and functional circuitry of amylin-controlled VTA-to-mPFC signaling in rats. RESULTS: To first establish that VTA amylin receptor (calcitonin receptor) activation can modulate mPFC activity, we showed that intra-VTA amylin decreased food-evoked mPFC cFos. VTA amylin delivery also attenuated food-directed impulsive behavior, implicating VTA amylin signaling as a regulator of mPFC functions. Palatable food activates VTA dopamine and mPFC neurons. Accordingly, dopamine receptor agonism in the mPFC blocked the hypophagic effect of intra-VTA amylin, and VTA amylin injection reduced food-evoked phasic dopamine levels in the mPFC, supporting the idea that VTA calcitonin receptor activation decreases dopamine release in the mPFC. Surprisingly, calcitonin receptor expression was not found on VTA-to-mPFC projecting neurons but was instead found on GABAergic (gamma-aminobutyric acidergic) interneurons in the VTA that provide monosynaptic inputs to this pathway. Blocking intra-VTA GABA signaling, through GABA receptor antagonists and DREADD (designer receptor exclusively activated by designer drugs)-mediated GABAergic neuronal silencing, attenuated intra-VTA amylin-induced hypophagia. CONCLUSIONS: These results indicate that VTA amylin signaling stimulates GABA-mediated inhibition of dopaminergic projections to the mPFC to mitigate impulsive consumption of palatable foods.

What does high value care for musculoskeletal conditions mean and how do you apply it in practice? A consensus statement from a research network of physiotherapists in New South Wales, Australia.

OBJECTIVES: To develop a physiotherapist-led consensus statement on the definition and provision of high-value care for people with musculoskeletal conditions. DESIGN: We performed a three-stage study using Research And Development/University of California Los Angeles Appropriateness Method methodology. We reviewed evidence about current definitions through a rapid literature review and then performed a survey and interviews with network members to gather consensus. Consensus was finalised in a face-to-face meeting. SETTING: Australian primary care. PARTICIPANTS: Registered physiotherapists who are members of a practice-based research network (n=31). RESULTS: The rapid review revealed two definitions, four domains of high value care and seven themes of high-quality care. Online survey responses (n=26) and interviews (n=9) generated two additional high-quality care themes, a definition of low-value care, and 21 statements on the application of high value care. Consensus was reached for three working definitions (high value, high-quality and low value care), a final model of four high value care domains (high-quality care, patient values, cost-effectiveness, reducing waste), nine high-quality care themes and 15 statements on application. CONCLUSION: High value care for musculoskeletal conditions delivers most value for the patient, and the clinical benefits outweigh the costs to the individual or system providing the care. High-quality care is evidence based, effective and safe care that is patient-centred, consistent, accountable, timely, equitable and allows easy interaction with healthcare providers and healthcare systems.

Trends in Intake and Outcome Data From U.S. Animal Shelters From 2016 to 2020.

In this retrospective, exploratory study, intake and outcome data were compiled from 1,373 U.S. animal shelters for which such data were reported consistently across a five-year study period (2016-2020). Linear regression analysis was used to examine the five-year trends and the impacts of the first year of the COVID-19 pandemic (2020) on the overall trends in intake and outcomes in U.S. animal shelters. The results of the analysis reveal that total intake and euthanasia for both dogs and cats significantly decreased over the study period. The adoption, return-to-owner, return-to-field, and transfer (for cats) categories as a percentage of intake all showed significant increases. Live release rates as a function of total intakes and total outcomes for both dogs and cats showed significant increases over the study period. The findings from this study address a critical gap in the field by summarizing emerging trends at the national level in how cats and dogs are being served in U.S. animal shelters.

Vapor Cannabis Exposure Generationally Affects Male Reproductive Functions in Mice.

This study was performed to examine whether vapor exposure to cannabis plant matter negatively impacts male reproductive functions and testis development in mice. Adult CD-1 male mice (F0) were exposed to air (control) or 200 mg of vaporized cannabis plant matter 3×/day over a 10-day period. Subsequently, F0 males were bred with drug-naïve CD-1 females to generate F1 males, and F1 offspring were used to generate F2 males. Cannabis vapor exposure decreased sperm count and/or motility in F0 and F1 males and disrupted the progression of germ cell development, as morphometric analyses exhibited an abnormal distribution of the stages of spermatogenesis in F0 males. Although plasma levels of testosterone were not affected by cannabis exposure in any ages or generations of males, dysregulated steroidogenic enzymes, Cyp11a1 and Cyp19a1, were observed in F0 testis. In the neonatal testis from F1 males, although apoptosis was not altered, DNA damage and DNMT1, but not DNMT3A and DNMT3B, were increased in germ cells following cannabis exposure. In contrast, the alterations of DNA damage and DNMT1 expression were not observed in F2 neonatal males. These results suggest that cannabis vapor exposure generationally affects male reproductive functions, probably due to disruption of spermatogenesis in the developing testis.

In-Season Nutrition Strategies and Recovery Modalities to Enhance Recovery for Basketball Players: A Narrative Review.

Basketball players face multiple challenges to in-season recovery. The purpose of this article is to review the literature on recovery modalities and nutritional strategies for basketball players and practical applications that can be incorporated throughout the season at various levels of competition. Sleep, protein, carbohydrate, and fluids should be the foundational components emphasized throughout the season for home and away games to promote recovery. Travel, whether by air or bus, poses nutritional and sleep challenges, therefore teams should be strategic about packing snacks and fluid options while on the road. Practitioners should also plan for meals at hotels and during air travel for their players. Basketball players should aim for a minimum of 8 h of sleep per night and be encouraged to get extra sleep during congested schedules since back-to back games, high workloads, and travel may negatively influence night-time sleep. Regular sleep monitoring, education, and feedback may aid in optimizing sleep in basketball players. In addition, incorporating consistent training times may be beneficial to reduce bed and wake time variability. Hydrotherapy, compression garments, and massage may also provide an effective recovery modality to incorporate post-competition. Future research, however, is warranted to understand the influence these modalities have on enhancing recovery in basketball players. Overall, a strategic well-rounded approach, encompassing both nutrition and recovery modality strategies, should be carefully considered and implemented with teams to support basketball players' recovery for training and competition throughout the season.

Review of Changes in the Reinforcing Effects of Alcohol in Weight Loss Surgery Patients.

PURPOSE OF REVIEW: The reinforcing effects of alcohol are well documented, and they have been shown to play a role in the development of alcohol use disorders (AUDs). Also well established is the fact that post-weight loss surgery (WLS) patients are at an increased risk for AUDs. In the current manuscript, we review the notion that the reinforcing effects of alcohol may change from before to after WLS and discuss a number of determinants of alcohol reinforcement change in WLS patients. RECENT FINDINGS: It has been increasingly well understood that WLS patients are at an increased risk for AUD, but empirical support for the mechanisms that may cause this phenomenon have been lacking. Recently, a model was proposed that offered a number of different potentially causal variables as mechanisms that result in increased risk for AUD in these surgical patients. Change in the extent to which alcohol is reinforcing to WLS patients may be key in determining the likelihood of AUDs in this group. We review a host of biological, psychological, and social variables that ultimately impact how reinforcing alcohol is to WLS patients.

Evaluation of Omega-3 Status in Professional Basketball Players.

ABSTRACT: Davis, JK, Freese, EC, Wolfe, AS, Basham, SA, and Stein, KMW. Evaluation of omega-3 status in professional basketball players. J Strength Cond Res 35(7): 1794-1799, 2021-Omega-3 polyunsaturated fatty acids (PUFA) has been shown to promote muscle remodeling, improve immune status, decrease muscle soreness, and help maintain explosive power. Research that has assessed omega-3 blood concentrations with athletes has primarily focused on the college athlete. However, limited work has been conducted with the professional athlete. Therefore, the purpose of this study was to evaluate the omega-3 PUFA blood concentrations, dietary, and supplement intake of professional basketball players. Blood collection occurred during preseason medical screenings and analyzed for eicosapentaenoic acid, docosahexaenoic acid, the omega-3 Index (O3i), and various fatty acids using dried blood spot sampling. The mean O3i of 119 professional basketball players was 5.02 + 1.19% (range, 2.84-9.76%). Dietary intake of players showed that 31% of players reported consuming no fish in their diet per week, with 61% of players reported consuming less than 2 servings of fish per week. Only 12 of the 119 players reported supplementing with omega-3 PUFA, which varied widely for dosage and frequency of supplementation. A moderate correlation was shown for O3i and dietary fish consumption per week (r = 0.58; p < 0.01) and fish consumption per month (r = 0.57; p < 0.01). A large number of players reported consuming less than the recommend amount of dietary fish per week and very few players reported supplementing with omega-3 PUFA. The low intake of omega-3 PUFA likely contributed, in part, to the majority of players having an O3i of less than 8%.

Neuromuscular, Endocrine, and Perceptual Recovery After a Youth American Football Game.

ABSTRACT: Davis, JK, Wolfe, AS, Basham, SA, Freese, EC, and De Chavez, PJD. Neuromuscular, endocrine, and perceptual recovery after a youth American football game. J Strength Cond Res 35(5): 1317-1325, 2021-American football is a high-intensity intermittent sport consisting of various movements and repeated collisions which highlights the importance of adequate recovery from a game to prepare for the next competition. Therefore, the purpose of this study was to determine the time course of recovery markers after a youth American football game. Thirteen male American football youth players were monitored for 7 days after a single football game. Baseline measures were taken 28 hours pregame for lower-body neuromuscular function by countermovement jumps (CMJs) to determine peak power (PP), jump height (JH), flight time (FT), and takeoff velocity (TOV). Saliva was analyzed for cortisol, testosterone, and C-reactive protein (CRP). Perceptual recovery was assessed by the modified profile of mood states (POMS), perceived recovery status (PRS), and a daily wellness questionnaire. These measures were repeated immediately postgame (30 minutes) and at 20, 44, 68, 92, 116, and 140 hours postgame. Compared with baseline values, there was a significant decrease (p < 0.05) in CMJ PP, JH, and TOV up to 68 hours postgame and FT 44 hours postgame. No significant difference existed among time points for salivary testosterone and CRP. Cortisol levels significantly increased postgame compared with baseline (p < 0.05). Total mood disturbance, assessed by POMS, and daily wellness markers for energy were significantly decreased (p < 0.05), whereas daily wellness markers for soreness were significantly increased (p < 0.05) immediately after the game. Players exhibited a significant decrease in PRS up to 44 hours postgame (p < 0.05), similar to the decrease in neuromuscular function. Neuromuscular function and PRS are impaired for up to 44-68 h postgame.

Genome-to-phenome research in rats: progress and perspectives.

Because of their relatively short lifespan (<4 years), rats have become the second most used model organism to study health and diseases in humans who may live for up to 120 years. First-, second- and third-generation sequencing technologies and platforms have produced increasingly greater sequencing depth and accurate reads, leading to significant advancements in the rat genome assembly during the last 20 years. In fact, whole genome sequencing (WGS) of 47 strains have been completed. This has led to the discovery of genome variants in rats, which have been widely used to detect quantitative trait loci underlying complex phenotypes based on gene, haplotype, and sweep association analyses. DNA variants can also reveal strain, chromosome and gene functional evolutions. In parallel, phenome programs have advanced significantly in rats during the last 15 years and more than 10 databases host genome and/or phenome information. In order to discover the bridges between genome and phenome, systems genetics and integrative genomics approaches have been developed. On the other hand, multiple level information transfers from genome to phenome are executed by differential usage of alternative transcriptional start (ATS) and polyadenylation (APA) sites per gene. We used our own experiments to demonstrate how alternative transcriptome analysis can lead to enrichment of phenome-related causal pathways in rats. Development of advanced genome-to-phenome assays will certainly enhance rats as models for human biomedical research.

Behavioral and Neurobiological Consequences of Hedonic Feeding on Alcohol Drinking.

A complex interplay of peripheral and central signaling mechanisms within the body of an organism maintains energy homeostasis. In addition, energy/food intake is modified by various external factors (e.g., palatability, food availability, social and environmental triggers). Highly palatable foods can provoke maladaptive feeding behavior, which in turn disrupts normal homeostatic regulation resulting in numerous health consequences. Furthermore, neuroendocrine peptides, traditionally considered to regulate appetite and energy homeostasis, also control the intake and reinforcing properties of alcohol and drugs of abuse. Therefore, dysregulated eating as a result of a hedonic/binge-like intake of hyper-palatable food may impact alcohol drinking behavior. Relevant in this case is the fact that eating disorders are highly comorbid with several neuropsychiatric conditions, including alcohol use disorder. The present review is intended to summarize the neurobiological and functional consequences of hedonic feeding on alcohol intake.

Effects of ethanol on plasma ghrelin levels in the rat during early and late adolescence.

Ghrelin is an appetite-regulating peptide that is primarily secreted by endocrine cells in the stomach and is implicated in regulation of alcohol consumption and alcohol-reinforced behaviors. In the present study, adolescent Sprague-Dawley rats received intermittent ethanol (AIE) exposure by intragastric intubation (5 g/kg) or vapor inhalation, manipulations conducted between postnatal days (PD) 28-43. On the first and last day of AIE exposure, the level of intoxication was examined 1 h after ethanol gavage or upon removal from the vapor chamber. This was immediately followed by a blood draw for determination of the blood ethanol concentration (BEC) and plasma levels of acylated ghrelin (acyl-ghrelin; active). On PD29, plasma levels of acyl-ghrelin were significantly elevated in male (but not female) rats in response to acute ethanol exposure by both gastric gavage and vapor inhalation. Importantly, assessment of plasma acyl-ghrelin in response to repeated ethanol exposure revealed a complex interaction of both sex and method of AIE exposure. On PD43, vapor inhalation increased plasma acyl-ghrelin in both males and females compared to their air-control counterparts, whereas there was no change in plasma levels of acyl-ghrelin in either male or female rats in response to exposure by intragastric gavage. Assessment of plasma acyl-ghrelin following a 30-day ethanol-free period revealed AIE exposure did not produce a change in basal levels. In addition, an acute ethanol challenge in adult rats of 5 g/kg via gastric gavage had no effect on plasma ghrelin levels when assessed 1 h after initiation of exposure. Collectively, these observations suggest that acyl-ghrelin, a primary gut-brain signaling hormone, is elevated by ethanol during early adolescence independent of administration route, and in gender-dependent fashion.

Nutritional Contingency Reduces Alcohol Drinking by Altering Central Neurotransmitter Receptor Gene Expression in Rats.

We have previously shown that 6 weeks of intermittent high-fat diet (Int-HFD) pre-exposure significantly reduced alcohol drinking in rats, providing preliminary evidence of the effectiveness of a dietary intervention in reducing alcohol intake. However, the functional framework and underlying neurobiological mechanisms of such dietary intervention are unknown. Here, we examined the impact of Int-HFD pre-exposure duration on alcohol drinking, plasma feeding peptides, and central neurotransmitter receptors gene expression. Male Long Evans rats (n = 6-7/group) received no pre-exposure, 1 or 2 weeks pre-exposure to Int-HFD and alcohol drinking (two-bottle choice) was evaluated. We observed HFD pre-exposure-dependent decrease in alcohol drinking, with a significant decrease observed following 2 weeks of Int-HFD pre-exposure. No significant between-group differences in plasma feeding peptides (i.e., ghrelin, leptin, insulin) were detected. A PCR array revealed that the expression of several neurotransmitter receptors was significantly (p < 0.05 and ≥2-fold) altered in the striatum and ventral tegmental area compared to controls. These data suggest that pre-exposure to a palatable diet is critical to reduce alcohol drinking in rats, possibly through genetic alterations in the brain reward circuitry. Importantly, the present study is a step forward in identifying the critical framework needed to evaluate the therapeutic potential of nutritional contingency in the management of alcoholism.

Recent Advances in the Neurobiology of Altered Motivation Following Bariatric Surgery.

PURPOSE OF REVIEW: There is compelling evidence in the clinical population that long-term weight loss secondary to bariatric surgery is mitigated by the reemergence of maladaptive feeding behaviors and in some cases new onset substance abuse. RECENT FINDINGS: A review of the current literature suggests that physical restructuring of the GI tract during WLS alters secretion of feeding peptides and nutrient-sensing mechanisms that directly target the brain's endogenous reward system, the mesolimbic dopamine system. Post-surgical changes in GI physiology augment activation of the mesolimbic system. In some patients, this process may contribute to a reduced appetite for palatable food whereas in others it may support maladaptive motivated behavior for food and chemical drugs. It is concluded that future studies are required to detail the timing and duration of surgical-induced changes in GI-mesolimbic communication to more fully understand this phenomenon.

Vapor Cannabis Exposure Promotes Genetic Plasticity in the Rat Hypothalamus.

It is well established that cannabis use promotes appetite. However, how cannabis interacts with the brain's appetite center, the hypothalamus, to stimulate feeding behavior is unknown. A growing body of evidence indicates that the hypothalamic transcriptome programs energy balance. Here, we tested the hypothesis that cannabis targets alternative polyadenylation (APA) sites within hypothalamic transcripts to regulate transcriptomic function. To do this, we used a novel cannabis vapor exposure model to characterize feeding in adult male Long Evans rats and aligned this behavioral response with APA events using a Whole Transcriptome Termini Sequencing (WTTS-Seq) approach as well as functional RNA abundance measurements with real-time quantitative polymerase chain reactions. We found that vapor cannabis exposure promoted food intake in free-feeding and behaviorally sated rats, validating the appetite stimulating properties of cannabis. Our WTTS-Seq analysis mapped 59 unique cannabis-induced hypothalamic APAs that occurred primarily within exons on transcripts that regulate synaptic function, excitatory synaptic transmission, and dopamine signaling. Importantly, APA insertions regulated RNA abundance of Slc6a3, the dopamine transporter, suggesting a novel genetic link for cannabis regulation of brain monoamine function. Collectively, these novel data indicate that a single cannabis exposure rapidly targets a key RNA processing mechanism linked to brain transcriptome function.

Changes in Alcohol Use after Metabolic and Bariatric Surgery: Predictors and Mechanisms.

PURPOSE OF REVIEW: This review synthesized the literature on predictors and mechanisms of post-bariatric alcohol problems, in order to guide future research on prevention and treatment targets. RECENT FINDINGS: Consistent evidence suggests an elevated risk of developing problems with alcohol following bariatric surgery. While there is a paucity of empirical data on predictors of problematic alcohol use after bariatric surgery, being male, a younger age, smoking, regular alcohol consumption, pre-surgical alcohol use disorder, and a lower sense of belonging have predicted alcohol misuse post-operatively. This review synthesizes potential mechanisms including specific bariatric surgical procedures, peptides and reinforcement/reward pathways, pharmacokinetics, and genetic influences. Finally, potential misperceptions regarding mechanisms are explored. Certain bariatric procedures elevate the risk of alcohol misuse post-operatively. Future research should serve to elucidate the complexities of reward signaling, genetically mediated mechanisms, and pharmacokinetics in relation to alcohol use across gender and developmental period by surgery type.

Examining the Impact of Estrogen on Binge Feeding, Food-Motivated Behavior, and Body Weight in Female Rats.

OBJECTIVE: Binge-eating disorder is associated with diminished self-control, emotional distress, and obesity. In this context, women are nearly twice as likely to develop binge-eating disorder and depression relative to men. Here, the physiological, psychological, and endocrine parameters were characterized in female rats subjected to a binge-eating protocol. METHODS: Nonrestricted female Long Evans rats (n = 8/group) received 2-hour restricted access to a high-fat diet (HFD) (4.54 kcal/g) every day or every third day. The progression of estrous cycling, the functional relevance of estrogen signaling for binge feeding, and binge-induced changes in food motivation were measured. RESULTS: Female rats developed a binge pattern of feeding that included alternation between caloric overconsumption and compensatory voluntary restriction without impacting estrous cycling. Notably, rats that received daily HFD exposure progressively decreased binge meals. Estrogen replacement in normal cycling or ovariectomized rats mimicked the reduction in body weight in female rats that received daily HFD access. Operant responding was unaffected by binge feeding; however, estrogen augmented operant performance in HFD-exposed rats. CONCLUSIONS: Collectively, these data suggest that estrogen protects against binge-induced increases in body weight gain without affecting food motivation in female rats.

Differentiated ratings of perceived exertion between overweight and non-overweight children during submaximal cycling.

OBJECTIVE: Few studies have examined differences in ratings of perceived exertion (RPE) between overweight (OW) and non-OW (NW) youth. With lower voluntary participation in physical activity in OW children, it seems plausible that these youth may experience elevated RPE. Therefore, this study compared RPE during two separate steady-state cycling bouts OW (>95th body mass index [BMI] percentile) and NW (<90th BMI percentile) children. METHODS: Participants completed one of two 20-min cycling trials; one performed at 70% age-predicted peak heart rate (HR) (70%) (OW n = 12 and NW n = 21) and a self-selected intensity (SS) (OW n = 6 and NW n = 13) with RPE overall, RPE legs (RPE-L), and RPE chest estimated at 5, 10, 15, and 20 min. RESULTS: A repeated measures ANOVA revealed that OW individuals had significantly lower RPE-L values at 5, 15, and 20 min during the SS trial. No significant differences were identified during the 70% trial. CONCLUSIONS: OW youth do not perceive cycling at 70% age-predicted peak HR or at SS intensities more difficult than NW children. It may be that cycling could serve as an attractive mode to encourage physical activity in this population and perhaps increase self-efficacy of exercise in this population.