1
|
Skinner TL, Desbrow B, Arapova J, Schaumberg MA, Osborne J, Grant GD, Anoopkumar-Dukie S, Leveritt MD. Women Experience the Same Ergogenic Response to Caffeine as Men. Med Sci Sports Exerc 2019; 51:1195-1202. [PMID: 30629046 DOI: 10.1249/mss.0000000000001885] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study aimed to determine whether 1) consumption of caffeine improves endurance cycling performance in women and 2) sex differences exist in the magnitude of the ergogenic and plasma responses to caffeine supplementation. METHODS Twenty-seven (11 women and 16 men) endurance-trained cyclists and triathletes participated in this randomized, double-blind, placebo-controlled, crossover study. Participants completed an incremental exercise test to exhaustion, two familiarization trials, and two performance trials. Ninety minutes before the performance trials, participants ingested opaque capsules containing either 3 mg·kg body mass of anhydrous caffeine or a placebo. They then completed a set amount of work (75% of peak sustainable power output) in the fastest possible time. Plasma was sampled at baseline, preexercise, and postexercise for caffeine. Strict standardization and verification of diet, hydration, training volume and intensity, and contraceptive hormone phase (for women) were implemented. RESULTS Performance time was significantly improved after caffeine administration in women (placebo: 3863 ± 419 s, caffeine: 3757 ± 312 s; P = 0.03) and men (placebo: 3903 ± 341 s, caffeine: 3734 ± 287 s; P < 0.001). The magnitude of performance improvement was similar for women (mean = 4.3%, 95% CI = 0.4%-8.2%) and men (4.6%, 2.3%-6.8%). Plasma caffeine concentrations were similar between sexes before exercise, but significantly greater in women after exercise (P < 0.001). CONCLUSIONS Ingestion of 3 mg·kg body mass of caffeine enhanced endurance exercise performance in women. The magnitude of the performance enhancement observed in women was similar to that of men, despite significantly greater plasma caffeine concentrations after exercise in women. These results suggest that the current recommendations for caffeine intake (i.e., 3-6 mg·kg caffeine before exercise to enhance endurance performance), which are derived almost exclusively from studies on men, may also be applicable to women.
Collapse
Affiliation(s)
- Tina L Skinner
- School of Human Movement and Nutrition Sciences, The University of Queensland, Queensland, AUSTRALIA
| | - Ben Desbrow
- School of Allied Health Sciences, Griffith University, Queensland, AUSTRALIA.,Menzies Health Institute Queensland, Griffith University, Queensland, AUSTRALIA
| | - Julia Arapova
- School of Human Movement and Nutrition Sciences, The University of Queensland, Queensland, AUSTRALIA
| | - Mia A Schaumberg
- School of Human Movement and Nutrition Sciences, The University of Queensland, Queensland, AUSTRALIA.,School of Health and Sports Sciences, University of the Sunshine Coast, Queensland, AUSTRALIA
| | - John Osborne
- School of Human Movement and Nutrition Sciences, The University of Queensland, Queensland, AUSTRALIA.,School of Exercise and Nutrition Sciences and Institute of Health and Biomedical Innovation, Queensland University of Technology, Queensland, AUSTRALIA
| | - Gary D Grant
- Menzies Health Institute Queensland, Griffith University, Queensland, AUSTRALIA.,Quality Use of Medicines Network, School of Pharmacy and Pharmacology, Griffith University, Queensland, AUSTRALIA
| | - Shailendra Anoopkumar-Dukie
- Menzies Health Institute Queensland, Griffith University, Queensland, AUSTRALIA.,Quality Use of Medicines Network, School of Pharmacy and Pharmacology, Griffith University, Queensland, AUSTRALIA
| | - Michael D Leveritt
- School of Human Movement and Nutrition Sciences, The University of Queensland, Queensland, AUSTRALIA
| |
Collapse
|
2
|
Von Ah Morano AE, Dorneles GP, Peres A, Lira FS. The role of glucose homeostasis on immune function in response to exercise: The impact of low or higher energetic conditions. J Cell Physiol 2019; 235:3169-3188. [PMID: 31565806 DOI: 10.1002/jcp.29228] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 09/03/2019] [Indexed: 12/20/2022]
Abstract
Immune cells are bioenergetically expensive during activation, which requires tightly regulated control of metabolic pathways. Both low and high glycemic conditions can modulate immune function. States of undernourishment depress the immune system, and in the same way, excessive intake of nutrients, such as an obesity state, compromise its functioning. Multicellular organisms depend on two mechanisms to survive: the regulation and ability to store energy to prevent starvation and the ability to fight against infection. Synergic interactions between metabolism and immunity affect many systems underpinning human health. In a chronic way, the breakdown of glycemic homeostasis in the body can influence cells of the immune system and consequently contribute to the onset of diseases such as type II diabetes, obesity, Alzheimer's, and fat and lean mass loss. On the contrary, exercise, recognized as a primary strategy to control hyperglycemic disorders, also induces a coordinated immune-neuro-endocrine response that acutely modulates cardiovascular, respiratory, and muscle functions and the immune response to exercise is widely dependent on the intensity and volume that may affect an immunodepressive state. These altered immune responses induced by exercise are modulated through the "stress hormones" adrenaline and cortisol, which are a threat to leukocyte metabolism. In this context, carbohydrates appear to have a positive acute response as a strategy to prevent depression of the immune system by maintaining plasma glucose concentrations to meet the energy demand from all systems involved during strenuous exercises. Therefore, herein, we discuss the mechanisms through which exercise may promotes changes on glycemic homeostasis in the metabolism and how it affects immune cell functions under higher or lower glucose conditions.
Collapse
Affiliation(s)
- Ana E Von Ah Morano
- Exercise and Immunometabolism Research Group, Department of Physical Education, Universidade Estadual Paulista (UNESP), Presidente Prudente, Brazil
| | - Gilson P Dorneles
- Department of Basic Health Sciences, Laboratory of Cellular and Molecular Immunology, Federal University of Health Sciences of Porto Alegre, Porto Alegre, Brazil
| | - Alessandra Peres
- Department of Basic Health Sciences, Laboratory of Cellular and Molecular Immunology, Federal University of Health Sciences of Porto Alegre, Porto Alegre, Brazil
| | - Fábio S Lira
- Exercise and Immunometabolism Research Group, Department of Physical Education, Universidade Estadual Paulista (UNESP), Presidente Prudente, Brazil
| |
Collapse
|
3
|
Barra NG, Fan IY, Gillen JB, Chew M, Marcinko K, Steinberg GR, Gibala MJ, Ashkar AA. High Intensity Interval Training Increases Natural Killer Cell Number and Function in Obese Breast Cancer-challenged Mice and Obese Women. J Cancer Prev 2017; 22:260-266. [PMID: 29302585 PMCID: PMC5751845 DOI: 10.15430/jcp.2017.22.4.260] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 11/30/2017] [Indexed: 01/09/2023] Open
Abstract
High intensity interval training (HIIT) boosts natural killer (NK) cell number and activity in normal weight breast cancer patients; however, whether this occurs in obese individuals is not well established. The goal of this study was to determine whether HIIT effectively boosts NK cells as a therapeutic strategy against breast cancer in an obese mouse model and in overweight/obese women. Diet induced female C57Bl/6 obese mice were assigned to undergo HIIT for four weeks or remain sedentary. Female participants were subjected to a six weeks HIIT protocol. HIIT mice acclimatized to treadmill running were subsequently injected with 5 × 105 polyoma middle T (MT) breast cancer cells intravenously. NK cell number and activation were monitored using flow cytometry, and tumor burden or lipid content evaluated from histological lung and liver tissues, respectively. In both mice and humans, circulating NK cell number and activation (CD3−NK1.1+CD27+ and CD3−CD56+, respectively) markedly increased immediately after HIIT. HIIT obese mice had reduced lung tumor burden compared to controls following MT challenge, and had diminished hepatic lipid deposition despite minimal body weight loss. Our findings demonstrate that HIIT can benefit obese individuals by enhancing NK cell number and activity, reducing tumor burden, and enhancing metabolic health.
Collapse
Affiliation(s)
- Nicole G Barra
- Department of Pathology and Molecular Medicine and McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada.,Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Isabella Y Fan
- Department of Pathology and Molecular Medicine and McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada.,Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Jenna B Gillen
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Marianne Chew
- Department of Pathology and Molecular Medicine and McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada.,Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | | | - Gregory R Steinberg
- Department of Medicine, McMaster University, Hamilton, ON, Canada.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Martin J Gibala
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Ali A Ashkar
- Department of Pathology and Molecular Medicine and McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada.,Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| |
Collapse
|
4
|
Morgado JP, Monteiro CP, Teles J, Reis JF, Matias C, Seixas MT, Alvim MG, Bourbon M, Laires MJ, Alves F. Immune cell changes in response to a swimming training session during a 24-h recovery period. Appl Physiol Nutr Metab 2016; 41:476-83. [PMID: 27028294 DOI: 10.1139/apnm-2015-0488] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Understanding the impact of training sessions on the immune response is crucial for the adequate periodization of training, to prevent both a negative influence on health and a performance impairment of the athlete. This study evaluated acute systemic immune cell changes in response to an actual swimming session, during a 24-h recovery period, controlling for sex, menstrual cycle phases, maturity, and age group. Competitive swimmers (30 females, 15 ± 1.3 years old; and 35 males, 16.5 ± 2.1 years old) performed a high-intensity training session. Blood samples were collected before, immediately after, 2 h after, and 24 h after exercise. Standard procedures for the assessment of leukogram by automated counting (Coulter LH 750, Beckman) and lymphocytes subsets by flow cytometry (FACS Calibur BD, Biosciences) were used. Subjects were grouped according to competitive age groups and pubertal Tanner stages. Menstrual cycle phase was monitored. The training session induced neutrophilia, lymphopenia, and a low eosinophil count, lasting for at least 2 h, independent of sex and maturity. At 24 h postexercise, the acquired immunity of juniors (15-17 years old), expressed by total lymphocytes and total T lymphocytes (CD3(+)), was not fully recovered. This should be accounted for when planning a weekly training program. The observed lymphopenia suggests a lower immune surveillance at the end of the session that may depress the immunity of athletes, highlighting the need for extra care when athletes are exposed to aggressive environmental agents such as swimming pools.
Collapse
Affiliation(s)
- José P Morgado
- a Laboratory of Physiology and Biochemistry of Exercise, Faculty of Human Kinetics, University of Lisbon, Portugal.,b Interdisciplinary Center for Human Performance Study (CIPER), Faculty of Human Kinetics, University of Lisbon, Portugal
| | - Cristina P Monteiro
- a Laboratory of Physiology and Biochemistry of Exercise, Faculty of Human Kinetics, University of Lisbon, Portugal.,b Interdisciplinary Center for Human Performance Study (CIPER), Faculty of Human Kinetics, University of Lisbon, Portugal
| | - Júlia Teles
- b Interdisciplinary Center for Human Performance Study (CIPER), Faculty of Human Kinetics, University of Lisbon, Portugal
| | - Joana F Reis
- b Interdisciplinary Center for Human Performance Study (CIPER), Faculty of Human Kinetics, University of Lisbon, Portugal.,c Escola de turismo, desporto e hospitalidade, Universidade Europeia, Lisbon, Portugal
| | - Catarina Matias
- a Laboratory of Physiology and Biochemistry of Exercise, Faculty of Human Kinetics, University of Lisbon, Portugal.,b Interdisciplinary Center for Human Performance Study (CIPER), Faculty of Human Kinetics, University of Lisbon, Portugal
| | - Maria T Seixas
- d Department of Health Promotion and Prevention of non-Communicable Diseases, National Health Institute Doutor Ricardo Jorge (INSA), Lisbon, Portugal
| | - Marta G Alvim
- d Department of Health Promotion and Prevention of non-Communicable Diseases, National Health Institute Doutor Ricardo Jorge (INSA), Lisbon, Portugal
| | - Mafalda Bourbon
- d Department of Health Promotion and Prevention of non-Communicable Diseases, National Health Institute Doutor Ricardo Jorge (INSA), Lisbon, Portugal
| | - Maria J Laires
- c Escola de turismo, desporto e hospitalidade, Universidade Europeia, Lisbon, Portugal
| | - Francisco Alves
- a Laboratory of Physiology and Biochemistry of Exercise, Faculty of Human Kinetics, University of Lisbon, Portugal.,b Interdisciplinary Center for Human Performance Study (CIPER), Faculty of Human Kinetics, University of Lisbon, Portugal
| |
Collapse
|
5
|
Millard AL, Valli PV, Stussi G, Mueller NJ, Yung GP, Seebach JD. Brief Exercise Increases Peripheral Blood NK Cell Counts without Immediate Functional Changes, but Impairs their Responses to ex vivo Stimulation. Front Immunol 2013; 4:125. [PMID: 23755049 PMCID: PMC3665937 DOI: 10.3389/fimmu.2013.00125] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 05/12/2013] [Indexed: 12/02/2022] Open
Abstract
Physical as well as psychological stress increases the number of circulating peripheral blood NK cells. Whereas some studies found a positive correlation between exercise and NK cell counts and cytotoxic activity, others showed that, for example, heavy training leads to a decrease in per cell NK cytotoxicity. Thus, the impact of exercise on NK cell function and eventually on altered immunocompetence remains to be elucidated. Here, we investigated whether a single bout of brief exercise, consisting in running up and down 150 stair-steps, affects the number and function of circulating NK cells. NK cells, obtained from 29 healthy donors, before and immediately after brief exercise, were assessed for numbers, phenotype, IFNγ production, degranulation, cytotoxicity, and in vitro response to stimulation with IL-2, IL-2/IL-12, or TLR2 agonists. Running resulted in a sixfold increase in the number of CD3−/CD56+ NK cells, but decreased the frequency of CD56bright NK cells about twofold. Brief exercise did not significantly interfere with baseline IFNγ secretion or NK cell cytotoxicity. In vitro stimulation with IL-2 and TLR2 agonists (lipoteichoic acid, and synthetic triacylated lipopeptide Pam3CSK4) enhanced IFNγ-secretion, degranulation, and cytotoxicity mediated by NK cells isolated pre-exercise, but had less effect on NK cells isolated following exercise. There were no differences in response to combined IL-2/IL-12 stimulation. In conclusion, having no obvious impact on baseline NK functions, brief exercise might be used as a simple method to significantly increase the number of CD56dim NK cell available for in vitro experiments. Nevertheless, the observed impaired responses to stimulation suggest an alteration of NK cell-mediated immunity by brief exercise which is at least in part explained by a concomitant decrease of the circulating CD56bright NK cell fraction.
Collapse
Affiliation(s)
- Anne-Laure Millard
- Division of Infectious Diseases and Hospital Epidemiology, University Hospital , Zürich , Switzerland
| | | | | | | | | | | |
Collapse
|
6
|
The influence of physical activity on the profile of immune response cells and cytokine synthesis in mice with experimental breast tumors induced by 7,12-dimethylbenzanthracene. Eur J Cancer Prev 2013; 22:251-8. [DOI: 10.1097/cej.0b013e3283592cbb] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
7
|
Radom-Aizik S, Zaldivar F, Haddad F, Cooper DM. Impact of brief exercise on peripheral blood NK cell gene and microRNA expression in young adults. J Appl Physiol (1985) 2013; 114:628-36. [PMID: 23288554 DOI: 10.1152/japplphysiol.01341.2012] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Natural killers (NK) cells are unique innate immune cells that increase up to fivefold in the circulating blood with brief exercise and are known to play a key role in first-response defense against pathogens and cancer immunosurveillance. Whether exercise alters NK cell gene and microRNA (miRNA) expression is not known. Thirteen healthy men (20-29 yr old) performed ten 2-min bouts of cycle ergometer exercise at a constant work equivalent to an average of 77% of maximum O2 consumption interspersed with 1-min rest. Blood was drawn before and immediately after the exercise challenge. NK cells were isolated from peripheral blood mononuclear cells using a negative magnetic cell separation method. We used Affymetrix U133+2.0 arrays for gene expression and Agilent Human miRNA V2 Microarray for miRNAs. A stringent statistical approach (false discovery rate < 0.05) was used to determine that exercise significantly altered the expression of 986 genes and 23 miRNAs. Using in silico analysis, we found exercise-related gene pathways where there was a high likelihood of gene-miRNA interactions. These pathways were predominantly associated with cancer and cell communication, including p53 signaling pathway, melanoma, glioma, prostate cancer, adherens junction, and focal adhesion. These data support the hypothesis that exercise affects the gene and miRNA expression pattern in the population of NK cells in the circulation and suggest mechanisms through which physical activity could alter health through the innate immune system.
Collapse
Affiliation(s)
- Shlomit Radom-Aizik
- Pediatric Exercise Research Center, Department of Pediatrics, University of California, Irvine, Irvine, California 92697-4094, USA.
| | | | | | | |
Collapse
|
8
|
Terra R, Silva SAGD, Pinto VS, Dutra PML. Efeito do exercício no sistema imune: resposta, adaptação e sinalização celular. REV BRAS MED ESPORTE 2012. [DOI: 10.1590/s1517-86922012000300015] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
INTRODUÇÃO: Durante o último século, o homem tornou-se menos ativo fisicamente, adotando hábitos cada vez mais sedentários. Isto promoveu aumento na incidência de doenças crônicas tais como doenças cardiovasculares, diabetes do tipo 2 e síndrome metabólica. A prática de atividade física pode influenciar o estado de higidez alterando estados metabólicos e também o sistema imunológico. OBJETIVO: Revisar na literatura estudos que abordem os efeitos promovidos pelo exercício físico no desenvolvimento da resposta imunológica e suas possíveis vias de transdução de sinais. MÉTODOS: Foram consultadas as bases de dados SciELO e PubMed. RESULTADOS: A literatura disponível mostra que durante a prática de exercício, várias subpopulações de leucócitos são alteradas de acordo com a intensidade e duração da atividade desempenhada. Exercícios de intensidade moderada estimulam uma resposta pró-inflamatória, enquanto aqueles de alta intensidade tendem a promover respostas anti-inflamatórias visando diminuir os danos na musculatura esquelética. Tais alterações são vistas em células apresentadoras de antígeno (como macrófagos e células dendríticas), neutrófilos, células natural killers (NK) e em moléculas de superfície como os receptores do tipo Toll (TLR) e do complexo principal de histocompatibilidade de classe II (MHC II), além das modificações promovidas em todo o repertório de citocinas. CONCLUSÃO: O estado atual do conhecimento permite considerar que as alterações no sistema imune são dependentes dos parâmetros inerentes ao exercício e que para que todas estas alterações ocorram, algumas cascatas de sinalização celular são acionadas, dando origem a um complexo processo de fosforilação/desfosforilação que culmina em ativação de fatores de transcrição, tradução de RNAm, síntese proteica e proliferação celular.
Collapse
|
9
|
Hypoxic exercise training promotes antitumour cytotoxicity of natural killer cells in young men. Clin Sci (Lond) 2011; 121:343-53. [DOI: 10.1042/cs20110032] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The cytotoxic functions of NKs (natural killer cells) are critical in enabling the immune system to cope efficiently with malignancy. In the present study, we compared how various exercise regimens without/with hypoxia influence phenotypic characteristics of NK subsets and cytotoxicity of NKs to NPCs (nasopharyngeal carcinoma cells). A total of 60 sedentary males were randomly divided into five groups. Each group (n=12) underwent one of five regimens: normoxic (21% O2) control (N-C), hypoxic (15% O2) control (H-C), normoxic exercise (50% maximal work rate under 21% O2; N-E), hypoxic relative exercise (50% maximal heart rate reserve under 15% O2; H-RE) or hypoxic absolute exercise (50% maximal work rate under 15% O2; H-AE) for 30 min/day, 5 days/week for 4 weeks. The results showed that hypoxic exercise regimens increased pulmonary ventilation and tissue oxygen utilization. Moreover, the H-RE regimen resulted in enhanced aerobic fitness at a less intensive training workload in the H-AE regimen. Before each regimen, strenuous exercise elevated NK perforin/granzyme B content and promoted cytotoxicity of NKs to NPCs. However, the percentage of NKs expressing homing (CD11a)/terminally differentiated (CD57)/inhibitory [KLRG1 (killer cell lectin-like receptor G1)] molecules that entered the bloodstream from peripheral tissues increased following this exercise. After 4 weeks, both the H-AE and H-RE regimens produced an up-regulated expression of memory (CD45RO)/activating (NKG2D) molecules and was accompanied by a decrease in CD57/KLRG1 levels on NKs at rest and after strenuous exercise. Furthermore, the two regimens increased resting and exercise NK perforin/granzyme B content and NK-induced phosphatidylserine exposure of NPCs. In contrast, no significant change in the phenotypic characteristics of blood NK subsets or NK-induced NPC apoptosis was observed in the N-C, H-C and N-E regimens. Therefore we conclude that 15% O2 exercise training reduces terminally differentiated NK subsets and up-regulates the expression of activating molecules and cytotoxic granule proteins in NKs, thereby enhancing the capacity of anti-NPC cytotoxicity by NKs. These findings could help to determine effective hypoxic exercise regimens for improving individual aerobic capacity and simultaneously promoting the natural cytotoxicity of NKs.
Collapse
|
10
|
Influence of Chlorella powder intake during swimming stress in mice. Biochem Biophys Res Commun 2011; 404:121-6. [DOI: 10.1016/j.bbrc.2010.11.078] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Accepted: 11/17/2010] [Indexed: 11/22/2022]
|
11
|
McFarlin BK, Hutchison AT, Kueht ML. Knowledge of carbohydrate consumption does not alter natural killer cell activity following an acute bout of high-intensity aerobic exercise. Appl Physiol Nutr Metab 2008; 33:1007-12. [DOI: 10.1139/h08-076] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Carbohydrate consumption during strenuous aerobic exercise reportedly minimizes post-exercise suppression of the innate immune system. One of the most common measurements of innate immunity is natural killer cell activity (NKCA). It is not known whether actual carbohydrate consumption or merely the knowledge of carbohydrate consumption mediates alteration in NKCA. The purpose of the present investigation was to determine if knowledge of carbohydrate beverage could result in alteration of RPE and NKCA, independent of actual carbohydrate intake. We recruited 11 male and female endurance athletes and randomly assigned them to either a correct or false knowledge of carbohydrate intake, such that in the false group, subjects were informed that they were receiving the carbohydrate beverage (CHO), but actually received a placebo (PLA) beverage. CHO and PLA beverages were matched to be similar in taste and appearance. Subjects completed 60 min of cycle ergometry (74% of VO2 peak). Venous blood samples were collected before (PRE), immediately after (POST), and 2 h after (2H) exercise and used to determine plasma glucose concentration, leukocyte total and differential counts, and NKCA. Data were statistically analyzed using a 3-factor analysis of variance (ANOVA) (p < 0.05). We did not find a significant effect of knowledge of drink type on leukocyte count, leukocyte differential, or NKCA. Drink type did not significantly alter leukocyte total, differential counts, or NKCA. There was a significant effect of exercise on NKCA. Knowledge of drink type does not alter innate immunity following exercise as assessed by leukocyte counts and NKCA.
Collapse
Affiliation(s)
- Brian K. McFarlin
- Department of Health and Human Performance, Laboratory of Integrated Physiology, University of Houston, Houston, TX 77204-6015, USA
- Department of Exercise and Sport Science, St. Mary’s University, San Antonio, TX 78228, USA
| | - Alexander T. Hutchison
- Department of Health and Human Performance, Laboratory of Integrated Physiology, University of Houston, Houston, TX 77204-6015, USA
- Department of Exercise and Sport Science, St. Mary’s University, San Antonio, TX 78228, USA
| | - Michael L. Kueht
- Department of Health and Human Performance, Laboratory of Integrated Physiology, University of Houston, Houston, TX 77204-6015, USA
- Department of Exercise and Sport Science, St. Mary’s University, San Antonio, TX 78228, USA
| |
Collapse
|
12
|
Riddell MC. The endocrine response and substrate utilization during exercise in children and adolescents. J Appl Physiol (1985) 2008; 105:725-33. [PMID: 18420724 DOI: 10.1152/japplphysiol.00031.2008] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Adolescence is a time of rapid growth caused by significant changes in hormone levels. For many, it is also a time of increased physical activity and sport that places a large demand on energy reserves. Exercise is known to cause perturbations in endocrine and metabolic systems in children and adolescents, yet careful characterization of these responses is only now being conducted. It does not appear that prepubertal youth have a different muscle composition than adults. However, these youth do have a lower anaerobic capacity and a greater reliance on aerobic metabolism during activity. Prepubertal adolescents may have an immature glucose regulatory system that influences glycemic regulation at the onset of moderate exercise. During heavy exercise, muscle and blood lactate levels are lower in children than in adults and there is a greater reliance on fat as fuel. The exercise intensity that causes maximal fat oxidation rate and the relative rate of fat oxidation decreases as adolescents develop through puberty. The mechanism for the attenuated lipid utilization with the advancement of puberty, and the impact that this may have on body composition, are unknown. Surprisingly, prepubertal adolescents have relatively high rates of exogenous glucose oxidation, perhaps because of their smaller endogenous carbohydrate reserves. Further study is needed to determine the optimal exogenous carbohydrate feeding regimen for peak performance in adolescence. Studies are also needed to determine whether physical activity, at an intensity targeted to maximize fat oxidation, help to lower body adiposity in overweight youth.
Collapse
Affiliation(s)
- Michael C Riddell
- School of Kinesiology and Health Science, Faculty of Health York University, Toronto, ON, Canada M3J 1P3.
| |
Collapse
|
13
|
Sundström Y, Nilsson C, Lilja G, Kärre K, Troye-Blomberg M, Berg L. The expression of human natural killer cell receptors in early life. Scand J Immunol 2007; 66:335-44. [PMID: 17635811 DOI: 10.1111/j.1365-3083.2007.01980.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Natural killer (NK) cells play an important role in tumour immunosurveillance and the early defence against viral infections. Recognition of altered cells (i.e. infected- or tumour-cells) is achieved through a multiple receptor recognition strategy which gives the NK cells inhibitory or activating signals depending on the ligands present on the target cell. NK cells originate from the bone marrow where they develop and proliferate. However, further maturation processes and homeostasis of NK cells in peripheral blood are not well understood. To determine the proportions of cells and the expression of NK cell receptors, mononuclear cells from children at three time points during early childhood were compared, i.e. cord blood (CB), 2 and 5 years of age. The proportion of NK cells was high in CB, but the interferon-gamma (IFN-gamma) production low compared to later in life. In contrast, the proportion of T cells was low in CB. This may indicate a deviation of the regulatory function of NK cells in CB compared to later in life, implying an importance of innate immunity in early life before the adaptive immune system matures. Additionally, we found that the proportion of LIR-1(+) NK cells increased with increasing age while CD94(+)NKG2C(-) (NKG2A(+)) NK cells and the level of expression of NKG2D, NKp30 and NKp46 decreased with age. These age related changes in NK cell populations defined by the expression of activating and inhibitory receptors may be the result of pathogen exposure and/or a continuation of the maturation process that begins in the bone marrow.
Collapse
Affiliation(s)
- Y Sundström
- Department of Immunology, Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
| | | | | | | | | | | |
Collapse
|
14
|
Timmons BW, Bar-Or O. Evidence of sex-based differences in natural killer cell responses to exercise and carbohydrate intake in children. Eur J Appl Physiol 2007; 101:233-40. [PMID: 17551749 DOI: 10.1007/s00421-007-0495-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2007] [Indexed: 11/26/2022]
Abstract
Distinct natural killer (NK) cell subsets (CD56bright and CD56dim) are mobilized with exercise and these cells may serve adaptive functions. We determined the distribution of NK cell subsets in response to exercise and carbohydrate (CHO) intake in young girls and compared these responses with previous findings in young boys of the same age. Twelve girls (12 years old) cycled for 60 min at 70% VO2max while drinking 6% CHO or flavoured water. Blood was collected at rest, during (30 and 60 min) and following (30 and 60 min) exercise to identify NK cells as CD3-CD56bright or CD3-CD56dim. CD69 expression on total CD3-CD56+ cells was also determined. A trend (P=0.07) was found for a trial x time interaction in CD56dim cell counts, with values lower with CHO than with water. CHO intake did not influence CD56bright responses (P>or=0.39). The CD56bright:CD56dim ratio increased during recovery from exercise (P<0.001), compared to rest, with no effect of CHO intake (P=0.48). CD69 expression was not different between exercise or recovery and rest. Like young boys, girls experience an elevated CD56bright:CD56dim ratio during recovery from exercise and CHO intake attenuates the exercise-induced CD56dim but not CD56bright cell response. Unlike young boys, girls do not experience a CHO-induced increase in the CD56bright:CD56dim ratio during recovery and CD69 expression does not increase on CD3-CD56+ cells during recovery. We conclude that even in young children sex-based differences exist in the NK cell response to exercise and CHO intake.
Collapse
Affiliation(s)
- Brian W Timmons
- Children's Exercise and Nutrition Centre, Departments of Pediatrics, McMaster University, Hamilton, ON, Canada.
| | | |
Collapse
|
15
|
Devries MC, Hamadeh MJ, Phillips SM, Tarnopolsky MA. Menstrual cycle phase and sex influence muscle glycogen utilization and glucose turnover during moderate-intensity endurance exercise. Am J Physiol Regul Integr Comp Physiol 2006; 291:R1120-8. [PMID: 16690766 DOI: 10.1152/ajpregu.00700.2005] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Numerous studies from our and other laboratories have shown that women have a lower respiratory exchange ratio (RER) during exercise than equally trained men, indicating a greater reliance on fat oxidation. Differences in estrogen concentration between men and women likely play a role in this sex difference. Differing estrogen and progesterone concentrations during the follicular (FP) and luteal (LP) phases of the female menstrual cycle suggest that fuel use may also vary between phases. The purpose of the current study was to determine the effect of menstrual cycle phase and sex upon glucose turnover and muscle glycogen utilization during endurance exercise. Healthy, recreationally active young women (n = 13) and men (n = 11) underwent a primed constant infusion of [6,6-2H]glucose with muscle biopsies taken before and after a 90-min cycling bout at 65% peak O2 consumption. LP women had lower glucose rate of appearance (Ra, P = 0.03), rate of disappearance (Rd, P = 0.03), and metabolic clearance rate (MCR, P = 0.04) at 90 min of exercise and lower proglycogen (P = 0.04), macroglycogen (P = 0.04), and total glycogen (P = 0.02) utilization during exercise compared with FP women. Men had a higher RER (P = 0.02), glucose Ra (P = 0.03), Rd (P = 0.03), and MCR (P = 0.01) during exercise compared with FP women, and men had a higher RER at 75 and 90 min of exercise (P = 0.04), glucose Ra (P = 0.01), Rd (P = 0.01), and MCR (P = 0.001) and a greater PG utilization (P = 0.05) compared with LP women. We conclude that sex, and to a lesser extent menstrual cycle, influence glucose turnover and glycogen utilization during moderate-intensity endurance exercise.
Collapse
Affiliation(s)
- Michaela C Devries
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada L8N 3Z5
| | | | | | | |
Collapse
|