The influence of caffeine on lymphocyte activation after prolonged high-intensity exercise

Many athletes consume caffeine for its known ergogenic effects. Since being legitimised by its 2004 removal from the World Anti-Doping Agency prohibited list of substances, caffeine s ability to enhance performance has led to its widespread use amongst the athletic population. However, despite caffe...

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Main Author:	Deborah K. Fletcher
Format:	Default Thesis
Published:	2019
Subjects:	Other health sciences not elsewhere classified untagged Medical and Health Sciences not elsewhere classified
Online Access:	https://hdl.handle.net/2134/7047
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spelling	rr-article-96075472019-08-14T08:41:08Z The influence of caffeine on lymphocyte activation after prolonged high-intensity exercise Deborah K. Fletcher (7237067) Other health sciences not elsewhere classified untagged Medical and Health Sciences not elsewhere classified Many athletes consume caffeine for its known ergogenic effects. Since being legitimised by its 2004 removal from the World Anti-Doping Agency prohibited list of substances, caffeine s ability to enhance performance has led to its widespread use amongst the athletic population. However, despite caffeine s prevalence, little research has focused on the effect of caffeine ingestion on immune function both at rest and in response to exercise in humans. Therefore, the aim of this thesis was to investigate the influence of typically-used doses of caffeine (typical daily intake in training and competition doses) on aspects of innate and acquired immunity in response to prolonged exercise. At rest both a high (6 mg kg-1) and low dose (2 mg kg-1) of caffeine had little effect on antigen-stimulated T (CD4+ and CD8+) or natural killer (NK) lymphocyte activation, while a high dose of caffeine only increased the number of antigen-stimulated NK cells expressing CD69 1 h following caffeine ingestion (Chapter 4). In response to prolonged high intensity continuous cycling both high and low doses of caffeine increased the natural state of activation as well as the antigen-stimulated activation of NK cells 1 h after exercise cessation (Chapters 5 and 6). However, at the same time-point a high dose of caffeine decreased CD4+ and CD8+ cell activation (Chapter 5). One hour after high intensity intermittent shuttle running, a high dose of caffeine attenuated the exercise-induced increase in NK cell activation both in terms of the number of cells expressing CD69 and their geometric mean fluorescence intensity expression of CD69 (Chapter 7). These effects did not occur in response to intermittent exercise when 2 mg kg-1 caffeine was instead ingested in 3 repeated doses throughout the day (Chapter 7). In conclusion, the findings of this thesis demonstrate the complex actions of caffeine on antigen-stimulated T and NK lymphocyte activation 1 h after prolonged intensive exercise. However, the biological significance of these findings in terms of caffeine s potential to alter an individuals susceptibility to infection following prolonged high intensity exercise are yet to be determined. 2019-08-14T08:41:08Z Text Thesis 2134/7047 https://figshare.com/articles/thesis/The_influence_of_caffeine_on_lymphocyte_activation_after_prolonged_high_intensity_exercise/9607547 CC BY-NC-ND 4.0
institution	Loughborough University
collection	Figshare
topic	Other health sciences not elsewhere classified untagged Medical and Health Sciences not elsewhere classified
spellingShingle	Other health sciences not elsewhere classified untagged Medical and Health Sciences not elsewhere classified Deborah K. Fletcher The influence of caffeine on lymphocyte activation after prolonged high-intensity exercise
description	Many athletes consume caffeine for its known ergogenic effects. Since being legitimised by its 2004 removal from the World Anti-Doping Agency prohibited list of substances, caffeine s ability to enhance performance has led to its widespread use amongst the athletic population. However, despite caffeine s prevalence, little research has focused on the effect of caffeine ingestion on immune function both at rest and in response to exercise in humans. Therefore, the aim of this thesis was to investigate the influence of typically-used doses of caffeine (typical daily intake in training and competition doses) on aspects of innate and acquired immunity in response to prolonged exercise. At rest both a high (6 mg kg-1) and low dose (2 mg kg-1) of caffeine had little effect on antigen-stimulated T (CD4+ and CD8+) or natural killer (NK) lymphocyte activation, while a high dose of caffeine only increased the number of antigen-stimulated NK cells expressing CD69 1 h following caffeine ingestion (Chapter 4). In response to prolonged high intensity continuous cycling both high and low doses of caffeine increased the natural state of activation as well as the antigen-stimulated activation of NK cells 1 h after exercise cessation (Chapters 5 and 6). However, at the same time-point a high dose of caffeine decreased CD4+ and CD8+ cell activation (Chapter 5). One hour after high intensity intermittent shuttle running, a high dose of caffeine attenuated the exercise-induced increase in NK cell activation both in terms of the number of cells expressing CD69 and their geometric mean fluorescence intensity expression of CD69 (Chapter 7). These effects did not occur in response to intermittent exercise when 2 mg kg-1 caffeine was instead ingested in 3 repeated doses throughout the day (Chapter 7). In conclusion, the findings of this thesis demonstrate the complex actions of caffeine on antigen-stimulated T and NK lymphocyte activation 1 h after prolonged intensive exercise. However, the biological significance of these findings in terms of caffeine s potential to alter an individuals susceptibility to infection following prolonged high intensity exercise are yet to be determined.
format	Default Thesis
author	Deborah K. Fletcher
author_facet	Deborah K. Fletcher
author_sort	Deborah K. Fletcher (7237067)
title	The influence of caffeine on lymphocyte activation after prolonged high-intensity exercise
title_short	The influence of caffeine on lymphocyte activation after prolonged high-intensity exercise
title_full	The influence of caffeine on lymphocyte activation after prolonged high-intensity exercise
title_fullStr	The influence of caffeine on lymphocyte activation after prolonged high-intensity exercise
title_full_unstemmed	The influence of caffeine on lymphocyte activation after prolonged high-intensity exercise
title_sort	influence of caffeine on lymphocyte activation after prolonged high-intensity exercise
publishDate	2019
url	https://hdl.handle.net/2134/7047
_version_	1797731631289597952

The influence of caffeine on lymphocyte activation after prolonged high-intensity exercise

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