21 results on '"Paul T Morgan"'
Search Results
2. Short-term step reduction reduces citrate synthase activity without altering skeletal muscle markers of oxidative metabolism or insulin-mediated signaling in young males
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Leigh Breen, Paul T. Morgan, Brandon J. Shad, Gareth A. Wallis, Sophie J Edwards, and Ryan N. Marshall
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Male ,medicine.medical_specialty ,Oxidative metabolism ,Physiology ,Chemistry ,Insulin ,medicine.medical_treatment ,Cell Respiration ,Skeletal muscle ,Citrate (si)-Synthase ,Mitochondrion ,Oxidative Stress ,Young Adult ,Endocrinology ,medicine.anatomical_structure ,Signalling ,Physiology (medical) ,Internal medicine ,medicine ,Humans ,Muscle, Skeletal ,Young male ,Function (biology) ,Metabolic health - Abstract
Mitochondria are critical to skeletal muscle contractile function and metabolic health. Short-term periods of step reduction (SR) are associated with alterations in muscle protein turnover and mass. However, the effects of SR on mitochondrial metabolism/muscle oxidative metabolism and insulin-mediated signaling are unclear. We tested the hypothesis that the total and/or phosphorylated protein content of key skeletal muscle markers of mitochondrial/oxidative metabolism, and insulin-mediated signaling would be altered over 7 days of SR in young healthy males. Eleven, healthy, recreationally active males (means ± SE, age: 22 ± 1 yr, BMI: 23.4 ± 0.7 kg·m
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- 2021
3. No effect of five days of bed rest or short‐term resistance exercise prehabilitation on markers of skeletal muscle mitochondrial content and dynamics in older adults
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Ryan N. Marshall, Benoit Smeuninx, Alex P. Seabright, Paul T. Morgan, Philip J. Atherton, Andrew Philp, and Leigh Breen
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Male ,Mitochondrial Proteins ,Physiology ,Physiology (medical) ,Humans ,Preoperative Exercise ,Resistance Training ,Citrate (si)-Synthase ,Muscle, Skeletal ,Bed Rest ,Aged - Abstract
Bed rest (BR) results in significant impairments in skeletal muscle metabolism. Mitochondrial metabolism is reportedly highly sensitive to disuse, with dysregulated fission-fusion events and impaired oxidative function previously reported. The effects of clinically relevant short-term BR (≤5 days) on mitochondrial protein expression are presently unclear, as are the effects of exercise prehabilitation as a potential counteractive intervention. The present study examined the effects of a 5-day period of BR and short-term resistance exercise prehabilitation (ST-REP) on mitochondrial-protein content. Ten older men (71 ± 4 years) underwent 5 days of BR, completing four sessions of high-volume unilateral resistance exercise prehabilitation over 7 days beforehand. Muscle biopsies were obtained from the vastus lateralis in the non-exercised control and exercised legs, both pre- and post-prehabilitation and pre- and post-BR, to determine changes in citrate synthase enzyme activity and the expression of key proteins in the mitochondrial electron transport chain and molecular regulators of fission-fusion dynamics, biosynthesis, and mitophagy. We observed no significant effect of either BR or ST-REP on citrate synthase protein content, enzyme activity, or ETC complex I-V protein content. Moreover, we observed no significant changes in markers of mitochondrial fission and fusion (p-DRP1
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- 2022
4. The effect of short‐term exercise prehabilitation on skeletal muscle protein synthesis and atrophy during bed rest in older men
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Sophie J Edwards, Matthew S. Brook, Leigh Breen, Konstantinos N. Manolopoulos, Nima Gharahdaghi, Alison Rushton, Paul T. Morgan, Andrew Philp, Yasir S Elhassan, Kenneth Smith, Philip J. Atherton, Benoit Smeuninx, and Elizabeth Sapey
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Male ,0301 basic medicine ,Sarcopenia ,medicine.medical_specialty ,lcsh:Diseases of the musculoskeletal system ,Prehabilitation ,medicine.medical_treatment ,Blood lipids ,Bed rest ,lcsh:QM1-695 ,03 medical and health sciences ,0302 clinical medicine ,Atrophy ,Physiology (medical) ,Internal medicine ,medicine ,Humans ,Orthopedics and Sports Medicine ,Muscle, Skeletal ,Exercise ,Aged ,Aged, 80 and over ,business.industry ,Preoperative Exercise ,Skeletal muscle ,Original Articles ,lcsh:Human anatomy ,medicine.disease ,Muscular Atrophy ,030104 developmental biology ,Postprandial ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Cardiology ,Muscle ,Original Article ,lcsh:RC925-935 ,Protein synthesis ,Myofibril ,business - Abstract
Background Poor recovery from periods of disuse accelerates age‐related muscle loss, predisposing individuals to the development of secondary adverse health outcomes. Exercise prior to disuse (prehabilitation) may prevent muscle deterioration during subsequent unloading. The present study aimed to investigate the effect of short‐term resistance exercise training (RET) prehabilitation on muscle morphology and regulatory mechanisms during 5 days of bed rest in older men. Methods Ten healthy older men aged 65–80 years underwent four bouts of high‐volume unilateral leg RET over 7 days prior to 5 days of inpatient bed rest. Physical activity and step‐count were monitored over the course of RET prehabilitation and bed rest, whilst dietary intake was recorded throughout. Prior to and following bed rest, quadriceps cross‐sectional area (CSA), and hormone/lipid profiles were determined. Serial muscle biopsies and dual‐stable isotope tracers were used to determine integrated myofibrillar protein synthesis (iMyoPS) over RET prehabilitation and bed rest phases, and acute postabsorptive and postprandial myofibrillar protein synthesis (aMyoPS) rates at the end of bed rest. Results During bed rest, daily step‐count and light and moderate physical activity time decreased, whilst sedentary time increased when compared with habitual levels (P
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- 2020
5. Influence of muscle oxygenation and nitrate-rich beetroot juice supplementation on O2 uptake kinetics and exercise tolerance
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Brynmor C. Breese, Andrew M. Jones, Stuart P. Cocksedge, Leonardo Nogueira, Paul T. Morgan, Christopher Thompson, Lee J. Wylie, and Stephen J. Bailey
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0301 basic medicine ,Hyperoxia ,Cancer Research ,medicine.medical_specialty ,Physiology ,Chemistry ,Clinical Biochemistry ,Skeletal muscle ,Oxygenation ,030204 cardiovascular system & hematology ,Beetroot Juice ,Hypoxia (medical) ,Biochemistry ,Nitric oxide ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,Endocrinology ,Fraction of inspired oxygen ,Internal medicine ,medicine ,medicine.symptom ,Nitrite - Abstract
We tested the hypothesis that acute supplementation with nitrate (NO3−)-rich beetroot juice (BR) would improve quadriceps muscle oxygenation, pulmonary oxygen uptake ( V ˙ O 2 ) kinetics and exercise tolerance (Tlim) in normoxia and that these improvements would be augmented in hypoxia and attenuated in hyperoxia. In a randomised, double-blind, cross-over study, ten healthy males completed two-step cycle tests to Tlim following acute consumption of 210 mL BR (18.6 mmol NO3−) or NO3−-depleted beetroot juice placebo (PL; 0.12 mmol NO3−). These tests were completed in normobaric normoxia [fraction of inspired oxygen (FIO2): 21%], hypoxia (FIO2: 15%) and hyperoxia (FIO2: 40%). Pulmonary V ˙ O 2 and quadriceps tissue oxygenation index (TOI), derived from multi-channel near-infrared spectroscopy, were measured during all trials. Plasma [nitrite] was higher in all BR compared to all PL trials (P V ˙ O 2 in hypoxia (P 0.05). These findings indicate that BR supplementation is more likely to improve Tlim and peak V ˙ O 2 in situations when skeletal muscle is more hypoxic.
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- 2020
6. A longitudinal investigation into the relative age effect in an English professional football club: exploring the ‘underdog hypothesis’
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Adam L. Kelly, Mark R. Wilson, Matthew Cole, Lewis A. Gough, Craig A. Williams, Harry Knapman, Daniel T. Jackson, and Paul T. Morgan
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biology ,Athletes ,business.industry ,Distribution (economics) ,Physical Therapy, Sports Therapy and Rehabilitation ,Relative age effect ,biology.organism_classification ,Developmental psychology ,Football club ,Talent development ,Tourism, Leisure and Hospitality Management ,Orthopedics and Sports Medicine ,Psychology ,business ,Selection (genetic algorithm) - Abstract
Purpose: The relative age effect (RAE) refers to the bias influence of birthdate distribution, with athletes born later in the selection year being under-represented in talent development systems. ...
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- 2019
7. (-)-Epicatechin and its colonic metabolite hippuric acid protect against dexamethasone-induced atrophy in skeletal muscle cells
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Sophie J Edwards, Steven Carter, Thomas Nicholson, Sophie Louise Allen, Paul T Morgan, Simon Wyn Jones, Catarina Rendeiro, and Leigh Breen
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Muscular Atrophy ,Nutrition and Dietetics ,Endocrinology, Diabetes and Metabolism ,Muscle Fibers, Skeletal ,Clinical Biochemistry ,Humans ,Muscle, Skeletal ,Molecular Biology ,Biochemistry ,Catechin ,Dexamethasone - Abstract
Cocoa flavanols have been shown to improve muscle function and may offer a novel approach to protect against muscle atrophy. Hippuric acid (HA) is a colonic metabolite of (-)-epicatechin (EPI), the primary bioactive compound of cocoa, and may be responsible for the associations between cocoa supplementation and muscle metabolic alterations. Accordingly, we investigated the effects of EPI and HA upon skeletal muscle morphology and metabolism within an in vitro model of muscle atrophy. Under atrophy-like conditions (24h 100μM dexamethasone (DEX)), C2C12 myotube diameter was significantly greater following co-incubation with either 25μM HA (11.19±0.39μm) or 25μM EPI (11.01±0.21μm) compared to the vehicle control (VC; 7.61±0.16μm, both P.001). In basal and leucine-stimulated states, there was a significant reduction in myotube protein synthesis (MPS) rates following DEX treatment in VC (P = .024). Interestingly, co-incubation with EPI or HA abrogated the DEX-induced reductions in MPS rates, whereas no significant differences versus control treated myotubes (CTL) were noted. Furthermore, co-incubation with EPI or HA partially attenuated the increase in proteolysis seen in DEX-treated cells, preserving LC3 α/β II:I and caspase-3 protein expression in atrophy-like conditions. The protein content of PGC1α, ACC, and TFAM (regulators of mitochondrial function) were significantly lower in DEX-treated versus. CTL cells (all P.050). However, co-incubation with EPI or HA was unable to prevent these DEX-induced alterations. For the first time we demonstrate that EPI and HA exert anti-atrophic effects on C2C12 myotubes, providing novel insight into the association between flavanol supplementation and favourable effects on muscle health.
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- 2022
8. Montmorency cherry supplementation improves 15-km cycling time-trial performance
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Matthew J Barton, Joanna L. Bowtell, and Paul T. Morgan
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Adult ,Male ,Adolescent ,Physiology ,Ergogenic Effects ,Athletic Performance ,Antioxidants ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Time trial ,Animal science ,Physiology (medical) ,Vasoactive ,Exercise performance ,Humans ,Orthopedics and Sports Medicine ,Muscle, Skeletal ,Exercise ,Morning ,Flavonoids ,Inflammation ,Chemistry ,Public Health, Environmental and Occupational Health ,Polyphenols ,030229 sport sciences ,General Medicine ,Vascular function ,Muscle oxygenation ,Oxidative Stress ,C-Reactive Protein ,Dietary Supplements ,Original Article ,Completion time ,Cycling ,Montmorency cherry ,030217 neurology & neurosurgery - Abstract
Aim Montmorency cherries are rich in polyphenols that possess antioxidant, anti-inflammatory and vasoactive properties. We investigated whether 7-day Montmorency cherry powder supplementation improved cycling time-trial (TT) performance. Methods 8 trained male cyclists (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot {V}{{\text{O}}_{2{\text{peak}}}}$$\end{document}V˙O2peak: 62.3 ± 10.1 ml kg−1 min−1) completed 10-min steady-state (SS) cycling at ~ 65% \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot {V}{{\text{O}}_{2{\text{peak}}}}$$\end{document}V˙O2peak followed by a 15-km TT on two occasions. Participants consumed 6 pills per day (Montmorency cherry powder, MC; anthocyanin 257 mg day−1 or dextrose powder, PL) for a 7-day period, 3 pills in the morning and evening. Capillary blood [lactate] was measured at baseline, post SS and post TT. Pulmonary gas exchange and tissue oxygenation index (TOI) of m. vastus lateralis via near-infrared spectroscopy, were measured throughout. Results TT completion time was 4.6 ± 2.9% faster following MC (1506 ± 86 s) supplementation compared to PL (1580 ± 102 s; P = 0.004). Blood [lactate] was significantly higher in MC after SS (PL: 4.4 ± 2.1 vs. MC: 6.7 ± 3.3 mM, P = 0.017) alongside an elevated baseline TOI (PL: 68.7 ± 2.1 vs. MC: 70.4 ± 2.3%, P = 0.018). Discussion Montmorency cherry supplementation improved 15-km cycling TT performance. This improvement in exercise performance was accompanied by enhanced muscle oxygenation suggesting that the vasoactive properties of the Montmorency cherry polyphenols may underpin the ergogenic effects.
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- 2019
9. Road cycle TT performance: Relationship to the power-duration model and association with FTP
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Matthew I. Black, Anni Vanhatalo, Stephen J. Bailey, Paul T. Morgan, and Andrew M. Jones
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Adult ,Male ,Time Factors ,File Transfer Protocol ,030209 endocrinology & metabolism ,Physical Therapy, Sports Therapy and Rehabilitation ,Athletic Performance ,Curvature ,Sports Equipment ,03 medical and health sciences ,Oxygen Consumption ,0302 clinical medicine ,Time trial ,Statistics ,Humans ,Orthopedics and Sports Medicine ,Duration (project management) ,Mathematics ,sports equipment ,Pulmonary Gas Exchange ,030229 sport sciences ,Bicycling ,Power (physics) ,Critical power ,Exercise Test ,Constant (mathematics) - Abstract
To determine the accuracy of critical power (CP) and W' (the curvature constant of the power-duration relationship) derived from self-paced time-trial (TT) prediction trials using mobile power meters to predict 16.1-km road cycling TT performance. This study also aimed to assess the agreement between functional threshold power (FTP) and CP.Twelve competitive male cyclists completed an incremental test to exhaustion, a FTP test and 4-5 self-paced TT bouts on a stationary bike within the lab, and a 16.1 km road TT, using mobile power meters.CP and W' derived from the power-duration relationship closely predicted TT performance. The 16.1-km road TT completion time (26.7 ± 2.2 min) was not significantly different from and was significantly correlated with the predicted time-to-completion (27.5 ± 3.3 min, r = 0.89, P 0.01). CP and FTP were not significantly different (275 ± 40 W vs. 278 ± 42 W, P 0.05); however, the limits of agreement between CP and FTP were 30 to -36 W.The findings of this study indicate that CP and W' determined using mobile power meters during maximal, self-paced TT prediction trials can be used to accurately predict 16.1-km cycling performance, supporting the application of the CP and W' for performance prediction. However, the limits of agreement were too large to consider FTP and CP interchangeable.
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- 2018
10. Protein Source and Quality for Skeletal Muscle Anabolism in Young and Older Adults: A Systematic Review and Meta-Analysis
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Paul T. Morgan, Sophie J Edwards, Sophie L Allen, Jonathan I. Quinlan, Ryan N. Marshall, Dane O Harris, and Leigh Breen
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0301 basic medicine ,medicine.medical_specialty ,Low protein ,Anabolism ,Medicine (miscellaneous) ,030209 endocrinology & metabolism ,Gastroenterology ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Humans ,Muscle Strength ,Muscle, Skeletal ,Aged ,030109 nutrition & dietetics ,Nutrition and Dietetics ,business.industry ,Skeletal muscle ,Resistance Training ,medicine.disease ,Postprandial ,medicine.anatomical_structure ,Strictly standardized mean difference ,Sarcopenia ,Meta-analysis ,Lean body mass ,Body Composition ,Dietary Proteins ,business - Abstract
BACKGROUND There is much debate regarding the source/quality of dietary proteins in supporting indices of skeletal muscle anabolism. OBJECTIVE We performed a systematic review and meta-analysis to determine the effect of protein source/quality on acute muscle protein synthesis (MPS) and changes in lean body mass (LBM) and strength, when combined with resistance exercise (RE). METHODS A systematic search of the literature was conducted to identify studies that compared the effects of ≥2 dose-matched, predominantly isolated protein sources of varying "quality." Three separate models were employed as follows: 1) protein feeding alone on MPS, 2) protein feeding combined with a bout of RE on MPS, and 3) protein feeding combined with longer-term resistance exercise training (RET) on LBM and strength. Further subgroup analyses were performed to compare the effects of protein source/quality between young and older adults. A total of 27 studies in young (18-35 y) and older (≥60 y) adults were included. RESULTS Analysis revealed an effect favoring higher-quality protein for postprandial MPS at rest [mean difference (MD): 0.014%/h; 95% CI: 0.006, 0.021; P
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- 2020
11. Successful treatment of COVID-19 with remdesivir in the absence of humoral immunity
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Estee Torok, Rainer Doffinger, Ane Ogbe, Caoimhe Nic Fhogartaig, Carl-Philipp Hackstein, Nicholas J. Loman, Jimstan Periselneris, Paul Klenerman, Matthew Buckland, James Thaventhiran, Peter Nelson, Vinicius A Vieira, Stuart Bloor, Frederica Mescia, Tanya I. Coulter, Wioleta M. Zelek, John Bradley, Paul J. Lehner, Lorinda Turner, Lourdes Ceron-Gutierrez, Nicholas M. Provine, Luke W. Meredith, Heli Harvala Simmonds, Paul T. Morgan, Michael Hunter, Paul A. Lyons, James Galloway, Anna Yakovleva, Ian B. Wilkinson, Sara Lear, Ken R. Smith, Joanne D. Stockton, William L Hamilton, Lise J Estcourt, Laura Bergamaschi, Sofia Grigoriadou, Anna Smielewska, Nicholas Screaton, Dave Roberts, Lisa Devlin, Tiffeney Mann, Josh Quick, Willem H. Ouwehand, Erik J M Toonen, Ian Goodfellow, Devan Vaghela, Nick Matheson, Hossain Delowar Akther, and Sorena Kiani-Alikhan
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Text mining ,Coronavirus disease 2019 (COVID-19) ,business.industry ,Humoral immunity ,Immunology ,Biology ,business - Abstract
The response to the coronavirus disease 2019 (COVID-19) pandemic has been hampered by lack of an effective severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antiviral therapy. Here we report the successful use of remdesivir in a patient with COVID-19 and the prototypic genetic antibody deficiency X-linked agammaglobulinaemia (XLA). Despite evidence of complement activation and a robust T cell response, the patient developed persistent SARS-CoV-2 pneumonitis, without progressing to multi-organ involvement. His unusual clinical course identifies a key role for SARS-CoV-2 antibodies in both viral clearance and progression to severe disease. In the absence of these confounders, we took an experimental medicine approach to examine the in vivoutility of remdesivir. Over two independent courses of treatment, we observed a dramatic, temporally correlated clinical and virological response, leading to clinical resolution and viral clearance, with no evidence of acquired drug resistance. We therefore provide unambiguous evidence for the antiviral efficacy of remdesivir in vivo, and its potential benefit in selected patients.
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- 2020
12. Exploring the Impact of Obesity on Skeletal Muscle Function in Older Age
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Leigh Breen, Paul T. Morgan, and Benoit Smeuninx
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0301 basic medicine ,Gerontology ,Anabolism ,intramuscular lipids ,Endocrinology, Diabetes and Metabolism ,Adipose tissue ,lcsh:TX341-641 ,030209 endocrinology & metabolism ,Review ,metabolic syndrome ,sarcopenia ,03 medical and health sciences ,0302 clinical medicine ,Medicine ,Sarcopenic obesity ,Nutrition ,Nutrition and Dietetics ,muscle function ,business.industry ,Skeletal muscle ,sarcopenic-obesity ,medicine.disease ,Obesity ,anabolic resistance ,obesity paradox ,030104 developmental biology ,medicine.anatomical_structure ,Sarcopenia ,Metabolic syndrome ,business ,lcsh:Nutrition. Foods and food supply ,Obesity paradox ,Food Science - Abstract
Sarcopenia is of important clinical relevance for loss of independence in older adults. The prevalence of obesity in combination with sarcopenia (“sarcopenic-obesity”) is increasing at a rapid rate. However, whilst the development of sarcopenia is understood to be multi-factorial and harmful to health, the role of obesity from a protective and damaging perspective on skeletal muscle in aging, is poorly understood. Specifically, the presence of obesity in older age may be accompanied by a greater volume of skeletal muscle mass in weight-bearing muscles compared with lean older individuals, despite impaired physical function and resistance to anabolic stimuli. Collectively, these findings support a potential paradox in which obesity may protect skeletal muscle mass in older age. One explanation for these paradoxical findings may be that the anabolic response to weight-bearing activity could be greater in obese vs. lean older individuals due to a larger mechanical stimulus, compensating for the heightened muscle anabolic resistance. However, it is likely that there is a complex interplay between muscle, adipose, and external influences in the aging process that are ultimately harmful to health in the long-term. This narrative briefly explores some of the potential mechanisms regulating changes in skeletal muscle mass and function in aging combined with obesity and the interplay with sarcopenia, with a particular focus on muscle morphology and the regulation of muscle proteostasis. In addition, whilst highly complex, we attempt to provide an updated summary for the role of obesity from a protective and damaging perspective on muscle mass and function in older age. We conclude with a brief discussion on treatment of sarcopenia and obesity and a summary of future directions for this research field.
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- 2020
13. Influence of muscle oxygenation and nitrate-rich beetroot juice supplementation on O
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Stuart P, Cocksedge, Brynmor C, Breese, Paul T, Morgan, Leonardo, Nogueira, Christopher, Thompson, Lee J, Wylie, Andrew M, Jones, and Stephen J, Bailey
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Adult ,Male ,Cross-Over Studies ,Exercise Tolerance ,Nitrates ,Administration, Oral ,Quadriceps Muscle ,Fruit and Vegetable Juices ,Oxygen ,Kinetics ,Young Adult ,Oxygen Consumption ,Double-Blind Method ,Humans ,Beta vulgaris ,Hypoxia ,Nitrites - Abstract
We tested the hypothesis that acute supplementation with nitrate (NO
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- 2019
14. Acute acetaminophen ingestion improves performance and muscle activation during maximal intermittent knee extensor exercise
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Stephen J. Bailey, Joanna L. Bowtell, Anni Vanhatalo, Paul T. Morgan, Andrew M. Jones, Human Physiology and Sports Physiotherapy Research Group, and Physiotherapy, Human Physiology and Anatomy
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Adult ,Male ,medicine.medical_specialty ,Neuromuscular fatigue ,Sports medicine ,Physiology ,Analgesic ,Administration, Oral ,Electromyography ,Placebo ,Drug Administration Schedule ,03 medical and health sciences ,0302 clinical medicine ,Single-leg exercise ,Endurance training ,Physiology (medical) ,medicine ,Humans ,Ingestion ,Knee ,Orthopedics and Sports Medicine ,Muscle, Skeletal ,Exercise ,Acetaminophen ,Muscle fatigue ,medicine.diagnostic_test ,business.industry ,digestive, oral, and skin physiology ,Public Health, Environmental and Occupational Health ,030229 sport sciences ,General Medicine ,Analgesics, Non-Narcotic ,Critical torque ,Torque ,Anesthesia ,Muscle Fatigue ,Original Article ,business ,030217 neurology & neurosurgery ,Muscle Contraction ,medicine.drug - Abstract
Aim Acetaminophen is a commonly used medicine for pain relief and emerging evidence suggests that it may improve endurance exercise performance. This study investigated some of the physiological mechanisms by which acute acetaminophen ingestion might blunt muscle fatigue development. Methods Thirteen active males completed 60 × 3 s maximum voluntary contractions (MVC) of the knee extensors with each contraction separated by a 2 s passive recovery period. This protocol was completed 60 min after ingesting 1 g of maltodextrin (placebo) or 1 g of acetaminophen on two separate visits. Peripheral nerve stimulation was administered every 6th contraction for assessment of neuromuscular fatigue development, with the critical torque (CT), which reflects the maximal sustainable rate of oxidative metabolism, taken as the mean torque over the last 12 contractions. Surface electromyography was recorded continuously as a measure of muscle activation. Results Mean torque (61 ± 11 vs. 58 ± 14% pre-exercise MVC) and CT (44 ± 13 vs. 40 ± 15% pre-exercise MVC) were greater in the acetaminophen trial compared to placebo (both P 0.05). However, the decline in electromyography amplitude was attenuated in the acetaminophen trial, with electromyography amplitude being greater compared to placebo from 210 s onwards (P
- Published
- 2018
15. Enhanced Cycling Time-Trial Performance During Multiday Exercise With Higher-Pressure Compression Garment Wear
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Paul T. Morgan, Leigh Breen, James McKendry, and Ewan R Williams
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Male ,Physical Therapy, Sports Therapy and Rehabilitation ,030204 cardiovascular system & hematology ,Clothing ,03 medical and health sciences ,0302 clinical medicine ,Time trial ,Heart Rate ,Heart rate ,Medicine ,Humans ,Orthopedics and Sports Medicine ,Single-Blind Method ,Power output ,Cross-Over Studies ,biology ,business.industry ,030229 sport sciences ,Compression garment ,Crossover study ,Constriction ,Bicycling ,Blood pressure ,Anesthesia ,biology.protein ,Exercise Test ,Creatine kinase ,business ,Cycling - Abstract
Purpose: Compression garments are widely used as a tool to accelerate recovery from intense exercise and have also gained traction as a performance aid, particularly during periods of limited recovery. This study tested the hypothesis that increased pressure levels applied via high-pressure compression garments would enhance “multiday” exercise performance. Methods: A single-blind crossover design, incorporating 3 experimental conditions—loose-fitting gym attire (CON), low-compression (LC), and high-compression (HC) garments—was adopted. A total of 10 trained male cyclists reported to the laboratory on 6 occasions, collated into 3 blocks of 2 consecutive visits. Each “block” consisted of 3 parts, an initial high-intensity protocol, a 24-hour period of controlled rest while wearing the applied condition/garment (CON, LC, and HC), and a subsequent 8-km cycling time trial, while wearing the respective garment. Subjective discomfort questionnaires and blood pressure were assessed prior to each exercise bout. Power output, oxygen consumption, and heart rate were continuously measured throughout exercise, with plasma lactate, creatine kinase, and myoglobin concentrations assessed at baseline and the end of exercise, as well as 30 and 60 minutes postexercise. Results: Time-trial performance was significantly improved during HC compared with both CON and LC (HC = 277 [83], CON = 266 [89], and LC = 265 [77] W; P Conclusion: The pressure levels exerted via lower-limb compression garments influence their effectiveness for cycling performance, particularly in the face of limited recovery.
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- 2019
16. Nutritional Strategies to Offset Disuse-Induced Skeletal Muscle Atrophy and Anabolic Resistance in Older Adults: From Whole-Foods to Isolated Ingredients
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Ryan N. Marshall, Leigh Breen, Benoit Smeuninx, and Paul T. Morgan
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Male ,0301 basic medicine ,Aging ,Anabolism ,Muscle Proteins ,Nutritional Status ,Physiology ,lcsh:TX341-641 ,030209 endocrinology & metabolism ,Review ,03 medical and health sciences ,0302 clinical medicine ,Atrophy ,atrophy ,Fatty Acids, Omega-3 ,Valerates ,medicine ,Humans ,skeletal muscle ,Metabolic disease ,Muscle, Skeletal ,Exercise ,Aged ,030109 nutrition & dietetics ,Nutrition and Dietetics ,business.industry ,Resistance training ,Skeletal muscle ,Creatine ,medicine.disease ,Muscular Disorders, Atrophic ,Muscle atrophy ,Muscular Atrophy ,nutrition ,medicine.anatomical_structure ,inactivity ,ageing ,Ageing ,Dietary Supplements ,Diet, High-Protein ,Dietary Proteins ,disuse ,medicine.symptom ,protein ,business ,metabolism ,lcsh:Nutrition. Foods and food supply ,Food Science ,Skeletal muscle atrophy - Abstract
Preserving skeletal muscle mass and functional capacity is essential for healthy ageing. Transient periods of disuse and/or inactivity in combination with sub-optimal dietary intake have been shown to accelerate the age-related loss of muscle mass and strength, predisposing to disability and metabolic disease. Mechanisms underlying disuse and/or inactivity-related muscle deterioration in the older adults, whilst multifaceted, ultimately manifest in an imbalance between rates of muscle protein synthesis and breakdown, resulting in net muscle loss. To date, the most potent intervention to mitigate disuse-induced muscle deterioration is mechanical loading in the form of resistance exercise. However, the feasibility of older individuals performing resistance exercise during disuse and inactivity has been questioned, particularly as illness and injury may affect adherence and safety, as well as accessibility to appropriate equipment and physical therapists. Therefore, optimising nutritional intake during disuse events, through the introduction of protein-rich whole-foods, isolated proteins and nutrient compounds with purported pro-anabolic and anti-catabolic properties could offset impairments in muscle protein turnover and, ultimately, the degree of muscle atrophy and recovery upon re-ambulation. The current review therefore aims to provide an overview of nutritional countermeasures to disuse atrophy and anabolic resistance in older individuals.
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- 2020
17. Acetaminophen ingestion improves muscle activation and performance during a 3-min all-out cycling test
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Stephen J. Bailey, Paul T. Morgan, Joanna L. Bowtell, Anni Vanhatalo, and Andrew M. Jones
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Adult ,Male ,Time Factors ,Physiology ,Endocrinology, Diabetes and Metabolism ,Analgesic ,Electromyography ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Double-Blind Method ,Physiology (medical) ,Exercise performance ,Medicine ,Ingestion ,Humans ,Muscle Strength ,Muscle, Skeletal ,Acetaminophen ,Nutrition and Dietetics ,Cross-Over Studies ,medicine.diagnostic_test ,business.industry ,Muscle activation ,030229 sport sciences ,General Medicine ,Bicycling ,Anesthesia ,Critical power ,Muscle Fatigue ,Exercise Test ,Physical Endurance ,business ,Cycling ,030217 neurology & neurosurgery ,medicine.drug ,Muscle Contraction - Abstract
Acute acetaminophen (ACT) ingestion has been shown to enhance cycling time-trial performance. The purpose of this study was to assess whether ACT ingestion enhances muscle activation and critical power (CP) during maximal cycling exercise. Sixteen active male participants completed two 3-min all-out tests against a fixed resistance on an electronically braked cycle ergometer 60 min after ingestion of 1 g of ACT or placebo (maltodextrin, PL). CP was estimated as the mean power output over the final 30 s of the test and W′ (the curvature constant of the power–duration relationship) was estimated as the work done above CP. The femoral nerve was stimulated every 30 s to measure membrane excitability (M-wave) and surface electromyography (EMGRMS) was recorded continuously to infer muscle activation. Compared with PL, ACT ingestion increased CP (ACT: 297 ± 32 W vs. PL: 288 ± 31 W, P < 0.001) and total work done (ACT: 66.4 ± 6.5 kJ vs. PL: 65.4 ± 6.4 kJ, P = 0.03) without impacting W′ (ACT: 13.1 ± 2.9 kJ vs. PL: 13.6 ± 2.4 kJ, P = 0.19) or the M-wave amplitude (P = 0.66) during the 3-min all-out cycling test. Normalised EMGRMSamplitude declined throughout the 3-min protocol in both PL and ACT conditions; however, the decline in EMGRMSamplitude was attenuated in the ACT condition, such that the EMGRMSamplitude was greater in ACT compared with PL over the last 60 s of the test (P = 0.04). These findings indicate that acute ACT ingestion might increase performance and CP during maximal cycling exercise by enhancing muscle activation.
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- 2018
18. A randomised controlled trial exploring the effects of different beverages consumed alongside a nitrate-rich meal on systemic blood pressure
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Sinead T. J. McDonagh, Andrew M. Jones, Anni Vanhatalo, Paul T. Morgan, and Lee J. Wylie
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0301 basic medicine ,Adult ,Male ,Mediterranean diet ,Medicine (miscellaneous) ,Alcohol ,Blood Pressure ,Wine ,030204 cardiovascular system & hematology ,Nitric Oxide ,Nitric oxide ,Beverages ,03 medical and health sciences ,chemistry.chemical_compound ,Young Adult ,0302 clinical medicine ,Pharmacokinetics ,Nitrate ,Reference Values ,Vegetables ,Ingestion ,Medicine ,Humans ,Food science ,Meals ,Nitrites ,Meal ,Nutrition and Dietetics ,Cross-Over Studies ,Nitrates ,Ethanol ,business.industry ,Alcoholic Beverages ,Polyphenols ,General Medicine ,030104 developmental biology ,Blood pressure ,chemistry ,Female ,Nitrogen Oxides ,business - Abstract
Background: Ingestion of nitrate (NO3-)-containing vegetables, alcohol and polyphenols, separately, can reduce blood pressure (BP). However, the pharmacokinetic response to the combined ingestion of NO3- and polyphenol-rich or low polyphenol alcoholic beverages is unknown. Aim: The aim of this study was to investigate how the consumption of low and high polyphenolic alcoholic beverages combined with a NO3--rich meal can influence NO3- metabolism and systemic BP. Methods: In a randomised, crossover trial, 12 normotensive males (age 25 ± 5 years) ingested an acute dose of NO3- (∼6.05 mmol) in the form of a green leafy salad, in combination with either a polyphenol-rich red wine (NIT-RW), a low polyphenol alcoholic beverage (vodka; NIT-A) or water (NIT-CON). Participants also consumed a low NO3- salad and water as a control (CON; ∼0.69 mmol NO3-). BP and plasma, salivary and urinary [NO3-] and nitrite ([NO2-]) were determined before and up to 5 h post ingestion. Results: Each NO3--rich condition elevated nitric oxide (NO) biomarkers when compared with CON ( P < 0.05). The peak rise in plasma [NO2-] occurred 1 h after NIT-RW (292 ± 210 nM) and 2 h after NIT-A (318 ± 186 nM) and NIT-CON (367 ± 179 nM). Systolic BP was reduced 2 h post consumption of NIT-RW (-4 mmHg), NIT-A (-3 mmHg) and NIT-CON (-2 mmHg) compared with CON ( P < 0.05). Diastolic BP and mean arterial pressure were also lower in NIT-RW and NIT-A compared with NIT-CON ( P < 0.05). Conclusions: A NO3--rich meal, consumed with or without an alcoholic beverage, increases plasma [NO2-] and lowers systemic BP for 2–3 h post ingestion.
- Published
- 2018
19. Acute ibuprofen ingestion does not attenuate fatigue during maximal intermittent knee extensor or all-out cycling exercise
- Author
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Stephen J. Bailey, Andrew M. Jones, Anni Vanhatalo, Joanna L. Bowtell, and Paul T. Morgan
- Subjects
Adult ,Male ,Physiology ,Endocrinology, Diabetes and Metabolism ,Ibuprofen ,Electromyography ,Muscle Strength Dynamometer ,Placebo ,03 medical and health sciences ,0302 clinical medicine ,Physiology (medical) ,Exercise performance ,Medicine ,Ingestion ,Humans ,Knee ,Power output ,Peripheral Nerves ,Muscle, Skeletal ,Exercise ,Nutrition and Dietetics ,Knee extensors ,medicine.diagnostic_test ,business.industry ,Pulmonary Gas Exchange ,Anti-Inflammatory Agents, Non-Steroidal ,030229 sport sciences ,General Medicine ,Electric Stimulation ,Bicycling ,Anesthesia ,Muscle Fatigue ,business ,Cycling ,030217 neurology & neurosurgery ,medicine.drug ,Muscle Contraction - Abstract
Recent research suggests that acute consumption of pharmacological analgesics can improve exercise performance, but the ergogenic potential of ibuprofen (IBP) administration is poorly understood. This study tested the hypothesis that IBP administration would enhance maximal exercise performance. In one study, 13 physically active males completed 60 × 3-s maximal voluntary contractions (MVCs) of the knee extensors interspersed with 2-s passive recovery periods, on 2 occasions, with the critical torque (CT) estimated as the mean torque over the last 12 contractions (part A). In another study, 16 active males completed two 3-min all-out tests against a fixed resistance on an electronically braked cycle ergometer, with the critical power estimated from the mean power output over the final 30 s of the test (part B). All tests were completed 60 min after ingestion of maltodextrin (placebo, PL) or 400 mg of IBP. Peripheral nerve stimulation was administered at regular intervals and electromyography was measured throughout. For part A, mean torque (IBP: 60% ± 13% of pre-exercise MVC; PL: 58% ± 14% of pre-exercise MVC) and CT (IBP: 41% ± 16% of pre-exercise MVC; PL: 40% ± 15% of pre-exercise MVC) were not different between conditions (P > 0.05). For part B, end-test power output (IBP: 292 ± 28 W; PL: 288 ± 31 W) and work done (IBP: 65.9 ± 5.9 kJ; PL: 65.4 ± 6.4 kJ) during the 3-min all-out cycling tests were not different between conditions (all P > 0.05). For both studies, neuromuscular fatigue declined at a similar rate in both conditions (P > 0.05). In conclusion, acute ingestion of 400 mg of IBP does not improve single-leg or maximal cycling performance in healthy humans.
- Published
- 2018
20. Lowering of blood pressure after nitrate-rich vegetable consumption is abolished with the co-ingestion of thiocyanate-rich vegetables in healthy normotensive males
- Author
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Lee J. Wylie, Andrew M. Jones, Adam Linoby, Christopher Thompson, Paul T. Morgan, Ida Clarke, Luke J Connolly, Rebecca Dewhurst-Trigg, Paul G. Winyard, Jamie R. Blackwell, Stephen J. Bailey, and Toby Yeates
- Subjects
0301 basic medicine ,Adult ,Male ,Cancer Research ,Physiology ,Clinical Biochemistry ,Blood Pressure ,030204 cardiovascular system & hematology ,Biochemistry ,Nitric oxide ,Vascular health ,03 medical and health sciences ,chemistry.chemical_compound ,Young Adult ,0302 clinical medicine ,Nitrate ,Vegetables ,Ingestion ,Humans ,Food science ,Nitrite ,Cross-Over Studies ,Nitrates ,Thiocyanate ,Crossover study ,Healthy Volunteers ,030104 developmental biology ,Blood pressure ,chemistry ,Thiocyanates - Abstract
A diet rich in vegetables is known to provide cardioprotection. However, it is unclear how the consumption of different vegetables might interact to influence vascular health. This study tested the hypothesis that nitrate-rich vegetable consumption would lower systolic blood pressure but that this effect would be abolished when nitrate-rich and thiocyanate-rich vegetables are co-ingested. On four separate occasions, and in a randomized cross-over design, eleven healthy males reported to the laboratory and consumed a 750 mL vegetable smoothie that was either: low in nitrate (∼0.3 mmol) and thiocyanate (∼5 μmol), low in nitrate and high in thiocyanate (∼72 μmol), high in nitrate (∼4 mmol) and low in thiocyanate and high in nitrate and thiocyanate. Blood pressure as well as plasma and salivary [thiocyanate], [nitrate] and [nitrite] were assessed before and 3 h after smoothie consumption. Plasma [nitrate] and [nitrite] and salivary [nitrate] were not different after consuming the two high-nitrate smoothies, but salivary [nitrite] was higher after consuming the high-nitrate low-thiocyanate smoothie (1183 ± 625 μM) compared to the high-nitrate high-thiocyanate smoothie (941 ± 532 μM; P < .001). Systolic blood pressure was only lowered after consuming the high-nitrate low-thiocyanate smoothie (-3 ± 5 mmHg; P < .05). The acute consumption of vegetables high in nitrate and low in thiocyanate lowered systolic blood pressure. However, when the same dose of nitrate-rich vegetables was co-ingested with thiocyanate-rich vegetables the increase in salivary [nitrite] was smaller and systolic blood pressure was not lowered. These findings might have implications for optimising dietary guidelines aimed at improving cardiovascular health.
- Published
- 2017
21. Flavanol-Rich Cacao Mucilage Juice Enhances Recovery of Power but Not Strength from Intensive Exercise in Healthy, Young Men
- Author
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Paola M Wollman, Paul T. Morgan, Sarah R. Jackman, and Joanna L. Bowtell
- Subjects
0301 basic medicine ,Physical Therapy, Sports Therapy and Rehabilitation ,Knee extension ,Muscle damage ,Article ,lcsh:GV557-1198.995 ,recovery ,03 medical and health sciences ,muscle damage ,0302 clinical medicine ,One-repetition maximum ,Post exercise ,Medicine ,Orthopedics and Sports Medicine ,Blood markers ,anti-inflammatory ,lcsh:Sports ,030109 nutrition & dietetics ,business.industry ,anti-oxidant ,030229 sport sciences ,Venous blood ,Functional recovery ,Mucilage ,cacao juice ,Anesthesia ,flavanols ,business - Abstract
(1) Background: Mucilage within cacao pods contains high levels of polyphenols. We investigated whether consumption of cacao juice enhances the recovery of muscle function following intensive knee extension exercise. (2) Methods: Ten recreationally active males completed two trials of 10 sets of 10 single leg knee extensions at ~80% one repetition maximum. Participants consumed each supplement (ZumoCacao®, juice, CJ or a dextrose drink, PL) for 7 days prior to and 48 h post exercise. Knee extension maximum voluntary contraction (MVC) and a counter movement jump (CMJ) were performed at baseline, immediately, 24 h, and 48 h post-exercise. Venous blood samples were collected at each time point and analyzed for indices of inflammation, oxidative damage, and muscle damage. (3) Results: CMJ height recovered faster with CJ at 24 h and 48 h post-exercise (p <, 0.05), but there was no effect of CJ on recovery of MVC (both p >, 0.05). There was also no effect of the trial on any blood markers (all p >, 0.05). (4) Conclusions: Supplementation with CJ for 7 days prior to and 2 days after intensive knee extensor exercise improved functional recovery as shown by an improved recovery of CMJ up to 48 h post-exercise. However, the precise mechanism of action is unclear and requires further investigation.
- Published
- 2018
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