1
|
Kraemer RR, Kraemer BR. The effects of peripheral hormone responses to exercise on adult hippocampal neurogenesis. Front Endocrinol (Lausanne) 2023; 14:1202349. [PMID: 38084331 PMCID: PMC10710532 DOI: 10.3389/fendo.2023.1202349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 11/02/2023] [Indexed: 12/18/2023] Open
Abstract
Over the last decade, a considerable amount of new data have revealed the beneficial effects of exercise on hippocampal neurogenesis and the maintenance or improvement of cognitive function. Investigations with animal models, as well as human studies, have yielded novel understanding of the mechanisms through which endocrine signaling can stimulate neurogenesis, as well as the effects of exercise on acute and/or chronic levels of these circulating hormones. Considering the effects of aging on the decline of specific endocrine factors that affect brain health, insights in this area of research are particularly important. In this review, we discuss how different forms of exercise influence the peripheral production of specific endocrine factors, with particular emphasis on brain-derived neurotrophic factor, growth hormone, insulin-like growth factor-1, ghrelin, estrogen, testosterone, irisin, vascular endothelial growth factor, erythropoietin, and cortisol. We also describe mechanisms through which these endocrine responses to exercise induce cellular changes that increase hippocampal neurogenesis and improve cognitive function.
Collapse
Affiliation(s)
- Robert R. Kraemer
- Department of Kinesiology and Health Studies, Southeastern Louisiana University, Hammond, LA, United States
| | - Bradley R. Kraemer
- Department of Biological Sciences, University of Alabama in Huntsville, Huntsville, AL, United States
| |
Collapse
|
2
|
Ribeiro FM, Silva MA, Lyssa V, Marques G, Lima HK, Franco OL, Petriz B. The molecular signaling of exercise and obesity in the microbiota-gut-brain axis. Front Endocrinol (Lausanne) 2022; 13:927170. [PMID: 35966101 PMCID: PMC9365995 DOI: 10.3389/fendo.2022.927170] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 07/05/2022] [Indexed: 11/13/2022] Open
Abstract
Obesity is one of the major pandemics of the 21st century. Due to its multifactorial etiology, its treatment requires several actions, including dietary intervention and physical exercise. Excessive fat accumulation leads to several health problems involving alteration in the gut-microbiota-brain axis. This axis is characterized by multiple biological systems generating a network that allows bidirectional communication between intestinal bacteria and brain. This mutual communication maintains the homeostasis of the gastrointestinal, central nervous and microbial systems of animals. Moreover, this axis involves inflammatory, neural, and endocrine mechanisms, contributes to obesity pathogenesis. The axis also acts in appetite and satiety control and synthesizing hormones that participate in gastrointestinal functions. Exercise is a nonpharmacologic agent commonly used to prevent and treat obesity and other chronic degenerative diseases. Besides increasing energy expenditure, exercise induces the synthesis and liberation of several muscle-derived myokines and neuroendocrine peptides such as neuropeptide Y, peptide YY, ghrelin, and leptin, which act directly on the gut-microbiota-brain axis. Thus, exercise may serve as a rebalancing agent of the gut-microbiota-brain axis under the stimulus of chronic low-grade inflammation induced by obesity. So far, there is little evidence of modification of the gut-brain axis as a whole, and this narrative review aims to address the molecular pathways through which exercise may act in the context of disorders of the gut-brain axis due to obesity.
Collapse
Affiliation(s)
- Filipe M. Ribeiro
- Post-Graduation Program in Physical Education, Catholic University of Brasilia, Brasilia, Brazil
- Center for Proteomic and Biochemical Analysis, Post-Graduation in Genomic and Biotechnology Sciences, Catholic University of Brasilia, Brasília, Brazil
- Laboratory of Molecular Exercise Physiology - University Center of the Federal District - UDF, Brasilia, Brazil
| | - Maycon A. Silva
- Center for Proteomic and Biochemical Analysis, Post-Graduation in Genomic and Biotechnology Sciences, Catholic University of Brasilia, Brasília, Brazil
| | - Victória Lyssa
- Laboratory of Molecular Analysis, Graduate Program of Sciences and Technology of Health, University of Brasilia, Brasilia, Brazil
| | - Gabriel Marques
- Laboratory of Molecular Exercise Physiology - University Center of the Federal District - UDF, Brasilia, Brazil
| | - Henny K. Lima
- Center for Proteomic and Biochemical Analysis, Post-Graduation in Genomic and Biotechnology Sciences, Catholic University of Brasilia, Brasília, Brazil
| | - Octavio L. Franco
- Post-Graduation Program in Physical Education, Catholic University of Brasilia, Brasilia, Brazil
- Center for Proteomic and Biochemical Analysis, Post-Graduation in Genomic and Biotechnology Sciences, Catholic University of Brasilia, Brasília, Brazil
- S-Inova Biotech, Catholic University Dom Bosco, Biotechnology Program, Campo Grande, Brazil
| | - Bernardo Petriz
- Center for Proteomic and Biochemical Analysis, Post-Graduation in Genomic and Biotechnology Sciences, Catholic University of Brasilia, Brasília, Brazil
- Laboratory of Molecular Exercise Physiology - University Center of the Federal District - UDF, Brasilia, Brazil
- Postgraduate Program in Rehabilitation Sciences - University of Brasília, Brasília, Brazil
| |
Collapse
|
3
|
McCarthy O, Schmidt S, Christensen MB, Bain SC, Nørgaard K, Bracken R. The endocrine pancreas during exercise in people with and without type 1 diabetes: Beyond the beta-cell. Front Endocrinol (Lausanne) 2022; 13:981723. [PMID: 36147573 PMCID: PMC9485437 DOI: 10.3389/fendo.2022.981723] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 08/11/2022] [Indexed: 11/13/2022] Open
Abstract
Although important for digestion and metabolism in repose, the healthy endocrine pancreas also plays a key role in facilitating energy transduction around physical exercise. During exercise, decrements in pancreatic β-cell mediated insulin release opposed by increments in α-cell glucagon secretion stand chief among the hierarchy of glucose-counterregulatory responses to decreasing plasma glucose levels. As a control hub for several major glucose regulatory hormones, the endogenous pancreas is therefore essential in ensuring glucose homeostasis. Type 1 diabetes (T1D) is pathophysiological condition characterised by a destruction of pancreatic β-cells resulting in pronounced aberrations in glucose control. Yet beyond the beta-cell perhaps less considered is the impact of T1D on all other pancreatic endocrine cell responses during exercise and whether they differ to those observed in healthy man. For physicians, understanding how the endocrine pancreas responds to exercise in people with and without T1D may serve as a useful model from which to identify whether there are clinically relevant adaptations that need consideration for glycaemic management. From a physiological perspective, delineating differences or indeed similarities in such responses may help inform appropriate exercise test interpretation and subsequent program prescription. With more complex advances in automated insulin delivery (AID) systems and emerging data on exercise algorithms, a timely update is warranted in our understanding of the endogenous endocrine pancreatic responses to physical exercise in people with and without T1D. By placing our focus here, we may be able to offer a nexus of better understanding between the clinical and engineering importance of AIDs requirements during physical exercise.
Collapse
Affiliation(s)
- Olivia McCarthy
- Applied Sport, Technology, Exercise and Medicine Research Centre, Swansea University, Swansea, United Kingdom
- Steno Diabetes Center Copenhagen, Copenhagen University Hospital, Herlev, Denmark
- *Correspondence: Olivia McCarthy,
| | - Signe Schmidt
- Steno Diabetes Center Copenhagen, Copenhagen University Hospital, Herlev, Denmark
| | | | | | - Kirsten Nørgaard
- Steno Diabetes Center Copenhagen, Copenhagen University Hospital, Herlev, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Richard Bracken
- Applied Sport, Technology, Exercise and Medicine Research Centre, Swansea University, Swansea, United Kingdom
| |
Collapse
|
4
|
Dipla K, Kraemer RR, Constantini NW, Hackney AC. Relative energy deficiency in sports (RED-S): elucidation of endocrine changes affecting the health of males and females. Hormones (Athens) 2021; 20:35-47. [PMID: 32557402 DOI: 10.1007/s42000-020-00214-w] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/20/2020] [Indexed: 12/26/2022]
Abstract
The purpose of this review is to present a different perspective of the relative energy deficiency syndrome, to improve understanding of associated endocrine alterations, and to highlight the need for further research in this area. The term "female athlete triad" was coined over 25 years ago to describe three interrelated components: disordered eating, menstrual dysfunction, and low bone mass. The syndrome's etiology is attributed to energy intake deficiency relative to energy expenditure required for health, function, and daily living. Recently, it became clear that there was a need to broaden the term, as the disorder is not an issue of only three interrelated problems but of a whole spectrum of insults resulting from low energy availability (LEA; i.e., insufficient energy availability to cover basic physiological demands) that can potentially affect any exerciser, irrespective of gender. The new model, termed relative energy deficiency in sport (RED-S), has received greater scrutiny in sports medicine due to its effects on both health and performance in athletes of both sexes. RED-S results from low-energy diets (intentional or unintentional) and/or excessive exercise. Energy deficiency reduces hypothalamic pulsatile release of gonadotropin-releasing hormone, this impairing anterior pituitary release of gonadotropins. In women, reduced FSH and LH pulsatility produces hypoestrogenism, causing functional hypothalamic amenorrhea and decreased bone mass. In men, it reduces testosterone and negatively affects bone health. Moreover, LEA alters other hormonal pathways, causing physiological consequences, such as alteration of the thyroid hormone signaling pathways, leptin levels, carbohydrate metabolism, the growth hormone/insulin-like growth factor-1 axis, and sympathetic/parasympathetic tone. This review explains and clarifies the effects of RED-S in both sexes.
Collapse
Affiliation(s)
- Konstantina Dipla
- Department of Sports Science, Exercise Physiology and Biochemistry Laboratory, Serres, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Robert R Kraemer
- Department of Kinesiology and Health Studies, Exercise Physiology Laboratory, Southeastern Louisiana University, Hammond, LA, USA.
| | - Naama W Constantini
- Heidi Rotberg Sport Medicine Center, Shaare Zedek Medical Center, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Anthony C Hackney
- Department of Exercise & Sport Science, University of North Carolina, Chapel Hill, NC, USA
| |
Collapse
|
5
|
Hetrick MM, Naquin MR, Gillan WW, Williams BM, Kraemer RR. A Hydrothermally Processed Maize Starch and Its Effects on Blood Glucose Levels During High-Intensity Interval Exercise. J Strength Cond Res 2018; 32:3-12. [DOI: 10.1519/jsc.0000000000001856] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|
6
|
Jackson M, Fatahi F, Alabduljader K, Jelleyman C, Moore JP, Kubis HP. Exercise training and weight loss, not always a happy marriage: single blind exercise trials in females with diverse BMI. Appl Physiol Nutr Metab 2017; 43:363-370. [PMID: 29096069 DOI: 10.1139/apnm-2017-0577] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Individuals show high variability in body weight responses to exercise training. Expectations and motivation towards effects of exercise on body weight might influence eating behaviour and could conceal regulatory mechanisms. We conducted 2 single-blind exercise trials (4 weeks (study 1) and 8 weeks (study 2)) with concealed objectives and exclusion of individuals with weight loss intention. Circuit exercise training programs (3 times a week (45-90 min), intensity 50%-90% peak oxygen uptake for 4 and 8 weeks) were conducted. Thirty-four females finished the 4-week intervention and 36 females the 8-week intervention. Overweight/obese (OV/OB) and lean female participants' weight/body composition responses were assessed and fasting and postprandial appetite hormone levels (PYY, insulin, amylin, leptin, ghrelin) were measured before and after the intervention for understanding potential contribution to individuals' body weight response to exercise training (study 2). Exercise training in both studies did not lead to a significant reduction of weight/body mass index (BMI) in the participants' groups; however, lean participants gained muscle mass. Appetite hormones levels were significantly (p < 0.05) altered in the OV/OB group, affecting fasting (-24%) and postprandial amylin (-14%) levels. Investigation of individuals' BMI responses using multiple regression analysis revealed that levels of fasting leptin, postprandial amylin increase, and BMI were significant predictors of BMI change, explaining about 43% of the variance. In conclusion, tested exercise training did not lead to weight loss in female participants, while a considerable proportion of variance in body weight response to training could be explained by individuals' appetite hormone levels and BMI.
Collapse
Affiliation(s)
- Matthew Jackson
- College of Health & Behavioural Sciences, Bangor University, Bangor, LL57 2PZ, UK.,College of Health & Behavioural Sciences, Bangor University, Bangor, LL57 2PZ, UK
| | - Fardin Fatahi
- College of Health & Behavioural Sciences, Bangor University, Bangor, LL57 2PZ, UK.,College of Health & Behavioural Sciences, Bangor University, Bangor, LL57 2PZ, UK
| | - Kholoud Alabduljader
- College of Health & Behavioural Sciences, Bangor University, Bangor, LL57 2PZ, UK.,College of Health & Behavioural Sciences, Bangor University, Bangor, LL57 2PZ, UK
| | - Charlotte Jelleyman
- College of Health & Behavioural Sciences, Bangor University, Bangor, LL57 2PZ, UK.,College of Health & Behavioural Sciences, Bangor University, Bangor, LL57 2PZ, UK
| | - Jonathan P Moore
- College of Health & Behavioural Sciences, Bangor University, Bangor, LL57 2PZ, UK.,College of Health & Behavioural Sciences, Bangor University, Bangor, LL57 2PZ, UK
| | - Hans-Peter Kubis
- College of Health & Behavioural Sciences, Bangor University, Bangor, LL57 2PZ, UK.,College of Health & Behavioural Sciences, Bangor University, Bangor, LL57 2PZ, UK
| |
Collapse
|
7
|
Amylin and its G-protein-coupled receptor: A probable pathological process and drug target for Alzheimer's disease. Neuroscience 2017; 356:44-51. [PMID: 28528968 DOI: 10.1016/j.neuroscience.2017.05.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 05/11/2017] [Accepted: 05/12/2017] [Indexed: 12/31/2022]
Abstract
G-protein-coupled receptors (GPCRs) are shown to be involved in Alzheimer's disease (AD) pathogenesis. However, because GPCRs include a large family of membrane receptors, it is unclear which specific GPCR or pathway with rational ligands can become effective therapeutic targets for AD. Amylin receptor (AmR) is a GPCR that mediates several activities, such as improving glucose metabolism, relaxing cerebrovascular structure, modulating inflammatory reactions and potentially enhancing neural regeneration. Recent studies show that peripheral treatments with amylin or its clinical analog, pramlintide, reduced several components of AD pathology, including amyloid plaques, tauopathy, neuroinflammation and other components in the brain, corresponding with improved learning and memory in AD mouse models. Because amylin shares a similar secondary structure with amyloid-β peptide (Aβ), I propose that the AmR/GPCR pathway is disturbed by a large amount of Aβ in the AD brain, leading to tau phosphorylation, neuroinflammation and neuronal death in the pathological cascade. Amylin-type peptides, readily crossing the blood-brain barrier (BBB), are the rational ligands to enhance this GPCR pathway and may exhibit utility as novel therapeutic agents for treating AD.
Collapse
|
8
|
Kraemer RR, Castracane VD. Endocrine alterations from concentric vs. eccentric muscle actions: a brief review. Metabolism 2015; 64:190-201. [PMID: 25467839 DOI: 10.1016/j.metabol.2014.10.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 10/22/2014] [Accepted: 10/23/2014] [Indexed: 12/31/2022]
Abstract
Resistance exercise has a positive effect on many tissues, including heart, bone, skeletal muscle, and nervous tissue. Eccentric muscle actions offer a unique and a potentially beneficial form of exercise for maintaining and improving health. During resistance exercise, the effects of gravity, and mechanical properties of the sarcomere and connective tissue in skeletal muscle allow a greater muscle load during an eccentric (lengthening) muscle contraction than a concentric (shortening) muscle contraction. Consequently, older patients, patients with muscle or limb movement limitations or injuries, as well as cancer patients may be able to benefit from isolated eccentric muscle actions. There are specific physiological responses to eccentric muscle contractions. This review will describe the effects of different eccentric muscle contraction protocols on endocrine responses that could have positive effects on different tissues and recommend direction for future research.
Collapse
Affiliation(s)
- Robert R Kraemer
- Deparment of Kinesiology and Health Studies, Southeastern Louisiana University, Hammond, LA, 70402.
| | - V Daniel Castracane
- Department of Obstetrics and Gynecology, Texas Tech University Health Sciences Center, 701 W. 5th St. Odessa, TX, 79763
| |
Collapse
|
9
|
Qiu WQ, Zhu H. Amylin and its analogs: a friend or foe for the treatment of Alzheimer's disease? Front Aging Neurosci 2014; 6:186. [PMID: 25120481 PMCID: PMC4114192 DOI: 10.3389/fnagi.2014.00186] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 07/09/2014] [Indexed: 12/20/2022] Open
Abstract
Amylin, a gut-brain axis hormone, and amyloid-beta peptides (Aβ), a major component of the Alzheimer's disease (AD) brain, share several features, including similar β-sheet secondary structures, binding to the same receptor and being degraded by the same protease, insulin degrading enzyme (IDE). However, while amylin readily crosses the blood brain barrier (BBB) and mediates several activities including improving glucose metabolism, relaxing cerebrovascular structure, modulating inflammatory reaction and perhaps enhancing neural regeneration, Aβ has no known physiological functions. Thus, abundant Aβ in the AD brain could block or interfere with the binding of amylin to its receptor and hinder its functions. Recent studies using animal models for AD demonstrate that amylin and its analog reduce the AD pathology in the brain and improve cognitive impairment in AD. Given that, in addition to amyloid plaques and neurofibrillary tangles, perturbed cerebral glucose metabolism and cerebrovascular damage are the hallmarks of the AD brain, we propose that giving exogenous amylin type peptides have the potential to become a new avenue for the diagnosis and therapeutic of AD. Although amylin's property of self-aggregation may be a limitation to developing it as a therapeutic for AD, its clinical analog, pramlintide containing 3 amino acid differences from amylin, does not aggregate like human amylin, but more potently mediates amylin's activities in the brain. Pramlintide is an effective drug for diabetes with a favorable profile of safety. Thus a randomized, double-blind, placebo-controlled clinical trial should be conducted to examine the efficacy of pramlintide for AD. This review summarizes the knowledge and findings on amylin type peptides and discuss pros and cons for their potential for AD.
Collapse
Affiliation(s)
- Wei Qiao Qiu
- Department of Psychiatry, Boston University School of Medicine Boston, MA, USA ; Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine Boston, MA, USA ; Alzheimer's Disease Center, Boston University School of Medicine Boston, MA, USA
| | - Haihao Zhu
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine Boston, MA, USA
| |
Collapse
|
10
|
Kraemer RR, Francois M, Webb ND, Worley JR, Rogers SN, Norman RL, Shah U, Castracane VD. No effect of menstrual cycle phase on glucose and glucoregulatory endocrine responses to prolonged exercise. Eur J Appl Physiol 2013; 113:2401-8. [PMID: 23765198 DOI: 10.1007/s00421-013-2677-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Accepted: 06/01/2013] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Prolonged exercise requires increased utilization of blood glucose and adjustment of glucoregulatory hormones. Estrogen can reduce hepatic gluconeogenesis which could affect insulin concentrations. Amylin is co-secreted with insulin and controls influx of glucose into the blood. PURPOSE To determine the effect of menstrual cycle stage on glucose, leptin, and pancreatic hormone responses to prolonged (90 min) exercise. METHODS Five healthy, eumenorrheic women (24.6 ± 5.1 years; 67.4 ± 1 kg) were monitored for 3 months to determine menstrual cycle length. Subjects completed a preliminary session to determine exercise workloads and, in a fasted condition, completed two randomized 90-min treadmill exercise trials at 60 % VO2max during the early follicular (EFX) and mid-luteal phase (MLX) of their menstrual cycle. Blood samples were analyzed for glucose, insulin, C-peptide, amylin, glucagon, leptin, and cortisol concentrations at rest (-30 and 0 min), during exercise (18, 36, 54, 72, and 90 min) and after 20 min of recovery. RESULTS No changes in amylin, leptin, or cortisol occurred for EFX and MLX trials. A significant (p < 0.05) time effect occurred for glucose, insulin, and glucagon with reduced insulin across the exercise trial and increases in glucose and glucagon later in the trial, but there were no differences between the EFX and MLX trials. CONCLUSIONS Menstrual cycle stage does not affect glucose, insulin, C-peptide, amylin, glucagon, cortisol, and leptin responses to prolonged exercise; however, the exercise reduces insulin and increases glucose and glucagon concentrations. This is the first study to determine acute effects of exercise on amylin and other glucoregulatory hormone responses in women.
Collapse
Affiliation(s)
- Robert R Kraemer
- Department of Kinesiology and Health Studies, Southeastern Louisiana University, SLU10845, Hammond, LA 70402, USA.
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Kraemer RR, Castracane VD, Francois M, Ghanbari-Niaki A, Sirikul B, Valverde RA. Effects of prolonged exercise on agouti-related protein: a pilot study. Endocrine 2012; 42:436-41. [PMID: 22477065 DOI: 10.1007/s12020-012-9663-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 03/22/2012] [Indexed: 10/28/2022]
Abstract
Agouti-related protein (AgRP), is a signaling peptide that affects feeding behavior, energy homeostasis, and has also been shown to stimulate the hypothalamic-pituitary-adrenal axis. The purpose of this study was to determine the effects of 90 min of treadmill exercise on circulating AgRP concentrations and the relationship of AgRP responses to cortisol. Seven young males completed a preliminary trial followed by counterbalanced experimental and control trials 4-5 weeks apart. The experimental trial began 2.5 h after consumption of a standard nutrient beverage and consisted of treadmill exercise at 60 % of previously determined VO(2max) for 90 min. Blood samples were collected before (-30 and 0 min), during (18, 36, 54, 72, and 90 min), and following exercise (20, 40, and 60 min). Blood samples were collected in a resting, control trial at the same time points as the experimental trial. Plasma lactate was significantly higher in the exercise than the control trial. Although AgRP increased from 18 min of exercise to peak at 90 min, these increases were not significantly different than values in the control trial. Cortisol responses during the exercise trial were significantly higher than the control trial. AgRP concentrations during early exercise were positively correlated with cortisol levels later in recovery. The obtained data suggest that AgRP concentrations during prolonged steady-state exercise are associated with subsequent cortisol increases, but further study is required to determine whether there is a causal effect.
Collapse
Affiliation(s)
- Robert R Kraemer
- Department of Kinesiology and Health Studies, Southeastern Louisiana University, SLU10845, Hammond, LA 70402, USA.
| | | | | | | | | | | |
Collapse
|
12
|
Wright HE, McLellan TM, Stapleton JM, Hardcastle SG, Kenny GP. Cortisol and interleukin-6 responses during intermittent exercise in two different hot environments with equivalent WBGT. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2012; 9:269-279. [PMID: 22482790 DOI: 10.1080/15459624.2012.666467] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Blood marker concentrations such as cortisol (COR) and interleukin (IL)-6 are commonly used to evaluate the physiological strain associated with work in the heat. It is unclear, however, if hot environments of an equivalent thermal stress, as defined by a similar wet bulb globe temperature (WBGT), result in similar response patterns. This study examined markers of neuroendocrine (COR) and immune (IL-6) responses, as well as the cardiovascular and thermal responses, relative to changes in body heat content measured by whole-body direct calorimetry during work in two different hot environments with equivalent WBGT. Eight males performed a 2-hr heavy intermittent exercise protocol (six 15-min bouts of cycling at a constant rate of metabolic heat production (360W) interspersed by 5-min rest periods) in Hot/Dry (46°C, 10% relative humidity [RH]) and Warm/Humid (33°C, 60% RH) conditions (WBGT ∼ 29°C). Whole-body evaporative and dry heat exchange, change in body heat content (ΔH(b)), rectal temperature (T(re)), and heart rate were measured continuously. Venous blood was obtained at rest (PRE) and the end of each exercise bout for the measurement of changes in plasma volume (PV), plasma protein (an estimate of plasma water changes), COR, and IL-6. Ratings of perceived exertion and thermal sensation were measured during the last minute of each exercise bout. No differences existed for ΔH(b), heart rate, T(re),%ΔPV, plasma protein concentration, perceptual strain (thermal sensation, perceived exertion), and COR between the Hot/Dry and Warm/Humid conditions. IL-6 exhibited an interaction effect (p = 0.041), such that greater increases were observed in the Hot/Dry (Δ = 1.61 pg·mL(-1)) compared with the Warm/Humid (Δ = 0.64 pg·mL(-1)) environment. These findings indicate that work performed in two different hot environments with equivalent WBGT resulted in similar levels of thermal, cardiovascular, and perceptual strain, which support the use of the WBGT stress index. However, the greater IL-6 response in the Hot/Dry requires further research to elucidate the effects of different hot environments and work intensities.
Collapse
Affiliation(s)
- Heather E Wright
- University of Ottawa , Faculty of Health Sciences, Human and Environmental Physiology Research Unit, Ottawa, Canada
| | | | | | | | | |
Collapse
|
13
|
Kraemer RR, Francois MR, Sehgal K, Sirikul B, Valverde RA, Castracane VD. Amylin and selective glucoregulatory peptide alterations during prolonged exercise. Med Sci Sports Exerc 2011; 43:1451-6. [PMID: 21266924 DOI: 10.1249/mss.0b013e3182114ab9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
UNLABELLED Amylin is a pancreatic β-cell peptide that facilitates the regulation of blood glucose concentration by inhibiting release of glucagon and modulating gastric emptying. Prolonged exercise may alter amylin and aid in the maintenance of blood glucose concentration; however, no studies have investigated the effects of prolonged exercise on amylin. PURPOSE This study aimed to determine the effects of 90 min of treadmill exercise on amylin and other glucoregulatory hormone responses in a postprandial state. METHODS Eight young healthy males completed a preliminary trial for VO2max and body composition determination and subsequent experimental and control trials in a counterbalanced manner. The experimental trial subjects arrived at the laboratory at 8:00 a.m., 1 h after consumption of a standard nutrient beverage (Ensure Plus®). At 9:50 a.m., subjects initiated 90 min of treadmill exercise at 60% of VO2max. Blood samples were collected twice before exercise, every 18 min during exercise, and every 20 min during 1 h of recovery. A resting control trial was conducted in an identical manner without VO2 assessment. RESULTS Plasma glucose and leptin concentrations remained stable across exercise, whereas lactate significantly increased to peak at 18 min of exercise then gradually declined. Amylin, insulin, and C-peptide values significantly declined over the trials, with no difference between exercise and control days. Glucagon area-under-the-curve concentrations were significantly greater during the exercise than the control trials. There was a significant time effect and trial effect for cortisol with a higher concentration during the experimental trial than during the control trial. CONCLUSIONS In a postprandial state, prolonged exercise stimulates glucagon and cortisol increases that are associated with stable blood glucose and leptin concentrations; however, similar to postprandial state control condition, insulin, C-peptide, and amylin concentrations decline.
Collapse
Affiliation(s)
- Robert R Kraemer
- Department of Kinesiology and Health Studies, Southeastern Louisiana University, Hammond, LA, USA.
| | | | | | | | | | | |
Collapse
|
14
|
Hollander DB, Kilpatrick MW, Ramadan ZG, Reeves GV, Francois M, Blakeney A, Castracane VD, Kraemer RR. Load Rather Than Contraction Type Influences Rate of Perceived Exertion and Pain. J Strength Cond Res 2008; 22:1184-93. [DOI: 10.1519/jsc.0b013e31816a8bc2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
15
|
Broom DR, Stensel DJ, Bishop NC, Burns SF, Miyashita M. Exercise-induced suppression of acylated ghrelin in humans. J Appl Physiol (1985) 2007; 102:2165-71. [PMID: 17347386 DOI: 10.1152/japplphysiol.00759.2006] [Citation(s) in RCA: 173] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Ghrelin is an orexigenic hormone secreted from endocrine cells in the stomach and other tissues. Acylation of ghrelin is essential for appetite regulation. Vigorous exercise induces appetite suppression, but this does not appear to be related to suppressed concentrations of total ghrelin. This study examined the effect of exercise and feeding on plasma acylated ghrelin and appetite. Nine male subjects aged 19-25 yr participated in two, 9-h trials (exercise and control) in a random crossover design. Trials began at 0800 in the morning after an overnight fast. In the exercise trial, subjects ran for 60 min at 72% of maximum oxygen uptake between 0800 and 0900. After this, they rested for 8 h and consumed a test meal at 1100. In the control trial, subjects rested for 9 h and consumed a test meal at 1100. Area under the curve values for plasma acylated ghrelin concentration (assessed from venous blood samples) were lower over the first 3 h and the full 9 h of the exercise trial compared with the control trial: 317+/-135 vs. 510+/-186 pg.ml(-1).3 h and 917+/-342 vs. 1,401+/-521 pg.ml(-1).9 h (means+/-SE) respectively (P<0.05). Area under the curve values for hunger (assessed using a visual scale) were lower over the first 3 h of the exercise trial compared with the control trial (P=0.013). These findings demonstrate that plasma acylated ghrelin concentration and hunger are suppressed during running.
Collapse
Affiliation(s)
- D R Broom
- School of Sport and Exercise Sciences, Loughborough Univ., Leicestershire LE11 3TU, UK
| | | | | | | | | |
Collapse
|
16
|
Ghanbari-Niaki A. Ghrelin and glucoregulatory hormone responses to a single circuit resistance exercise in male college students. Clin Biochem 2006; 39:966-70. [PMID: 16979150 DOI: 10.1016/j.clinbiochem.2006.05.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Revised: 04/30/2006] [Accepted: 05/15/2006] [Indexed: 11/25/2022]
Abstract
INTRODUCTION It has been suggested that ghrelin may play a role in growth hormone (GH) secretion to exercise. OBJECTIVE The present study was designed to examine the effects of a single bout of circuit resistance exercise on plasma glucose, ghrelin, GH, and c-peptide, and cortisol. DESIGN AND METHODS Fourteen volunteer male physical education students completed a single bout circuit resistance training (10 exercises, three circuits, and at 60% of 1-RM). Blood samples were collected before, immediately after the exercise, and 24-h following the exercise protocol. RESULTS GH, glucose, and c-peptide showed a significant increase immediately after exercise and returned to pre exercise values over time. Plasma ghrelin showed a significant decrease immediately after the exercise and increased significantly 24-h following the exercise. CONCLUSION In conclusion, a decrease in plasma ghrelin following a single bout of circuit resistance exercise indicates that an increase in GH is not related to plasma ghrelin levels. An acute exercise-induced hyperphagia during the long-recovery was considered.
Collapse
Affiliation(s)
- Abbass Ghanbari-Niaki
- Department of Physical Education and Sport Sciences, University of Tarbiat Modarres, PO Box 14115-39, Tehran, Iran.
| |
Collapse
|
17
|
Kraemer RR, Aboudehen KS, Carruth AK, Durand RTJ, Acevedo EO, Hebert EP, Johnson LG, Castracane VD. Adiponectin responses to continuous and progressively intense intermittent exercise. Med Sci Sports Exerc 2003; 35:1320-5. [PMID: 12900685 DOI: 10.1249/01.mss.0000079072.23998.f3] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE Adiponectin is a recently discovered adipocyte protein that is lower in patients with coronary artery disease and in Type II diabetics who have insulin resistance. Regular exercise is known to be a preventative factor in the development of atherosclerosis and Type II diabetes. Acute exercise increases insulin sensitivity; however, it also increases beta-adrenergic and glucocorticoid activities that may suppress adiponectin expression. Two experiments were conducted to determine whether acute exercise affects adiponectin concentrations. METHODS In the first experiment, six healthy male subjects completed 30 min of heavy continuous running exercise at 79% of VO (2max). In the second experiment, well-trained runners completed strenuous intermittent exercise consisting of treadmill running at 60, 75, 90, and 100% VO (2max). A resting control trial for the second experiment was also conducted. RESULTS Glucose and insulin were not altered significantly in the first experiment, but both increased significantly (P < 0.05) in the second experiment. A significant increase (P < 0.05) in adiponectin in the first experiment was no longer significant after correction for plasma volumes shifts. In the second experiment, there were significant (P < 0.05) changes in adiponectin concentrations over time but not a significant difference between adiponectin responses in exercise and control trials. CONCLUSIONS The data suggest that 30 min of heavy continuous running or more strenuous intermittent running does not stimulate an increase in production and release of adiponectin, and small increases in adiponectin concentrations resulting from the exercise may be attributed to normal plasma volume shifts.
Collapse
|
18
|
Hollander DB, Durand RJ, Trynicki JL, Larock D, Castracane VD, Hebert EP, Kraemer RR. RPE, pain, and physiological adjustment to concentric and eccentric contractions. Med Sci Sports Exerc 2003; 35:1017-25. [PMID: 12783051 DOI: 10.1249/01.mss.0000069749.13258.4e] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE The purpose of the study was to compare perceptual (RPE and pain), cardiac (heart rate), lactate, and endocrine (cortisol) responses with concentric (CON) and eccentric (ECC) resistance exercise protocols using the same absolute workload. METHODS Eight healthy men with resistance-training experience participated in the study. Subjects completed two experimental trials consisting of either CON contractions or ECC contractions at the same absolute workload for each of four exercises: bench press, leg extension, military press, and leg curl. Subjects performed four sets of 12 repetitions at 80% of 10-RM with 90-s rest periods. Blood samples were taken before, immediately after, and 15-min postexercise. RESULTS There was a significant trial effect for RPE, with CON exercise eliciting a higher RPE than ECC exercise (6.71 +/- 0.51 and 4.10 +/- 0.27, respectively). A significant trial effect was also demonstrated for pain, with CON exercise producing a higher pain rating than ECC exercise (5.59 +/- 0.41 and 3.23 +/- 0.27, respectively). Significantly higher heart rates and lactates were also demonstrated during the CON trial. For cortisol, a significant interaction was revealed between the pre- and immediate posttrial measures but not an overall trial effect. Correlational analyses revealed a significant relationship between RPE and pain for both trials. CONCLUSIONS CON exercise elicits greater perceptual (higher RPE and pain rating), cardiac, lactate and cortisol response than ECC exercise at the same absolute workload. Data demonstrate that relative to absolute load, RPE and pain respond to resistance exercise in a similar fashion. Additionally, physiological cues are consistent with these perceptual data.
Collapse
Affiliation(s)
- Daniel B Hollander
- Department of Kinesiology and Health Studies, Southeastern Louisiana University, Hammond 70402, USA.
| | | | | | | | | | | | | |
Collapse
|
19
|
Abstract
Short-term exercise (<60 min) studies suggest that leptin concentrations are not acutely affected in healthy males and females. Most reports of reductions in serum leptin may be attributed to circadian rhythms or hemoconcentration. For long-term (> or =60 min) exercise, a reduction in leptin concentrations reported from 1 to 3 hr of running or cycling has been attributed to diurnal reduction in circulating leptin, independent of exercise. Exercise that produces a sufficient energy imbalance (kilocalorie intake versus kilocalorie expenditure) suppresses 24-hr mean and amplitude of the diurnal rhythm of leptin in women. Suppression of leptin concentrations may be counterbalanced by feeding and may explain consistent reports of reductions in leptin concentrations following extreme bouts of exercise such as marathons or ultramarathons. In addition, leptin concentrations are reduced 48 hr after long-term aerobic exercise and long-term resistance exercise is associated with delayed leptin reduction 9 hr postexercise. Training studies have documented that short-term exercise training (< or =12 weeks) does not affect leptin levels, with the exception of patients with type 2 diabetes. Exercise training protocols that result in reduced fat mass will lower leptin concentrations, thus, most investigators have reported leptin concentrations after accounting for fat loss. There are disparate findings concerning long-term (>12 weeks) training studies, with a number of studies finding no effect of training on leptin concentrations other than effects induced by fat loss, and other studies finding reductions in leptin concentrations after accounting for fat loss. Exercise training-induced reductions in leptin levels have been attributed to alterations in energy balance, improvements in insulin sensitivity, alterations in lipid metabolism, and unknown factors. Hormone replacement does not seem to affect leptin adaptations to training. Patients with type 2 diabetes show delayed effects of short-term resistance exercise on leptin concentrations, reduced leptin levels with long-term training, and appear to be more sensitive to training-induced leptin adaptations than other populations.
Collapse
Affiliation(s)
- Robert R Kraemer
- Department of Kinesiology and Health Studies, Southeastern Louisiana University, Hammond 70402, USA.
| | | | | |
Collapse
|