17 results on '"Paul T Morgan"'
Search Results
2. 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
3. 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
4. Contralateral fatigue during severe-intensity single-leg exercise: influence of acute acetaminophen ingestion
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Stephen J. Bailey, Andrew M. Jones, Jonathan Fulford, Paul T. Morgan, Rhys Banks, and Anni Vanhatalo
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Adult ,Male ,Knee Joint ,Physiology ,nonlocal muscle fatigue ,03 medical and health sciences ,Eating ,0302 clinical medicine ,Physiology (medical) ,31P-magnetic resonance spectroscopy ,medicine ,Ingestion ,Humans ,Knee ,Muscle, Skeletal ,Exercise ,Fatigue ,Acetaminophen ,intramuscular metabolites ,business.industry ,Electromyography ,030229 sport sciences ,Intensity (physics) ,Exercise Therapy ,body regions ,Paracetamol ,Anesthesia ,Leg exercise ,Muscle Fatigue ,intramuscular substrates ,business ,030217 neurology & neurosurgery ,medicine.drug ,Research Article ,Muscle Contraction - Abstract
Exhaustive single-leg exercise has been suggested to reduce time to task failure (Tlim) during subsequent exercise in the contralateral leg by exacerbating central fatigue development. We investigated the influence of acetaminophen (ACT), an analgesic that may blunt central fatigue development, on Tlim during single-leg exercise completed with and without prior fatiguing exercise of the contralateral leg. Fourteen recreationally active men performed single-leg severe-intensity knee-extensor exercise to Tlim on the left (Leg1) and right (Leg2) legs without prior contralateral fatigue and on Leg2 immediately following Leg1 (Leg2-CONTRA). The tests were completed following ingestion of 1-g ACT or maltodextrin [placebo (PL)] capsules. Intramuscular phosphorus-containing metabolites and substrates and muscle activation were assessed using 31P-MRS and electromyography, respectively. Tlim was not different between Leg1ACT and Leg1PL conditions (402 ± 101 vs. 390 ± 106 s, P = 0.11). There was also no difference in Tlim between Leg2ACT-CONTRA and Leg2PL-CONTRA (324 ± 85 vs. 311 ± 92 s, P = 0.10), but Tlim was shorter in Leg2ACT-CONTRA and Leg2PL-CONTRA than in Leg2CON (385 ± 104 s, both P < 0.05). There were no differences in intramuscular phosphorus-containing metabolites and substrates or muscle activation between Leg1ACT and Leg1PL and between Leg2ACT-CONTRA and Leg2PL-CONTRA (all P > 0.05). These findings suggest that levels of metabolic perturbation and muscle activation at Tlim are not different during single-leg severe-intensity knee-extensor exercise completed with or without prior fatiguing exercise of the contralateral leg. Despite contralateral fatigue, ACT ingestion did not alter neuromuscular responses, muscle metabolites, or exercise performance.
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- 2019
5. The role of protein hydrolysates for exercise-induced skeletal muscle recovery and adaptation: a current perspective
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Leigh Breen and Paul T. Morgan
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medicine.medical_specialty ,RC620-627 ,Anabolism ,030309 nutrition & dietetics ,Supplementation ,Endocrinology, Diabetes and Metabolism ,Medicine (miscellaneous) ,030209 endocrinology & metabolism ,Clinical nutrition ,Review ,Isolates ,Hydrolysate ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Protein biosynthesis ,TX341-641 ,Protein hydrolysates ,Nutritional diseases. Deficiency diseases ,chemistry.chemical_classification ,0303 health sciences ,Nutrition and Dietetics ,Chemistry ,Nutrition. Foods and food supply ,Skeletal muscle ,Hydrolysates ,Muscle protein anabolism ,Amino acid ,Endocrinology ,medicine.anatomical_structure ,Concentrates ,Adaptation ,Protein synthesis - Abstract
The protein supplement industry is expanding rapidly and estimated to have a multi-billion market worth. Recent research has centred on understanding how the manufacturing processes of protein supplements may impact muscle recovery and remodeling. The hydrolysed forms of protein undergo a further heating extraction process during production which may contribute to amino acids (AA) appearing in circulation at a slightly quicker rate, or greater amplitude, than the intact form. Whilst the relative significance of the rate of aminoacidemia to muscle protein synthesis is debated, it has been suggested that protein hydrolysates, potentially through the more rapid delivery and higher proportion of di-, tri- and smaller oligo-peptides into circulation, are superior to intact non-hydrolysed proteins and free AAs in promoting skeletal muscle protein remodeling and recovery. However, despite these claims, there is currently insufficient evidence to support superior muscle anabolic properties compared with intact non-hydrolysed proteins and/or free AA controls. Further research is warranted with appropriate protein controls, particularly in populations consuming insufficient amounts of protein, to support and/or refute an important muscle anabolic role of protein hydrolysates. The primary purpose of this review is to provide the reader with a current perspective on the potential anabolic effects of protein hydrolysates in individuals wishing to optimise recovery from, and maximise adaptation to, exercise training.
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- 2021
6. 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
7. 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
8. Quadriceps muscle electromyography activity during physical activities and resistance exercise modes in younger and older adults
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Eduardo Martinez-Valdes, Ryan N. Marshall, Leigh Breen, and Paul T. Morgan
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0301 basic medicine ,Aging ,medicine.medical_specialty ,Activities of daily living ,endocrine system diseases ,Electromyography ,Biochemistry ,Article ,Quadriceps Muscle ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,Physical medicine and rehabilitation ,Activities of Daily Living ,Genetics ,medicine ,Humans ,Muscle, Skeletal ,Molecular Biology ,Exercise ,Aged ,medicine.diagnostic_test ,Knee extensors ,business.industry ,Resistance exercise training ,Stair climbing ,Quadriceps muscle ,Resistance training ,Resistance Training ,Cell Biology ,medicine.disease ,Ageing ,030104 developmental biology ,Younger adults ,Sarcopenia ,Muscle ,business ,human activities ,030217 neurology & neurosurgery ,Muscle Contraction - Abstract
Background Understanding the root cause of the age-related impairment in muscle adaptive remodelling with resistance exercise training (RET) and developing pragmatic and accessible resistance exercise for older adults, are essential research directives. Methods We sought to determine whether indices of quadriceps muscle EMG activity in response to different modes of RET and activities of daily living (ADL), differed between 15 healthy younger (25 ± 3 years) and 15 older (70 ± 5 years) adults. On four separate days, participants completed a maximal voluntary contraction (MVC) of the knee extensors, followed by a 15 m walking task, stair climbing task (i.e. ADL) and lower-limb RET through body-weight squats (BW-RET) and seated knee extensions on a machine (MN-RET) or via elastic bands (EB-RET). Surface quadriceps electromyography (EMG) was measured throughout all tasks to provide indirect estimates of changes in muscle activity. Results MVC was significantly greater in young vs. older adults (Young: 256 ± 72 vs. Old: 137 ± 48 N·m, P 0.05). Conclusions In conclusion, relative quadriceps muscle EMG activity was higher across a range of activities/exercise modes in older vs. younger adults. The similar quadriceps muscle EMG activity between EB-RET and MN-RET provides a platform for detailed investigation of the neuromuscular and muscle metabolic responses to such pragmatic forms of RET to strengthen the evidence-base for this mode of RET as a potential countermeasure to sarcopenia., Highlights • Ageing results in severe declines of neuromuscular function and strength. • Activities of daily living require greater relative muscle activity in older compared with younger adults. • Elastic band resistance exercise produces comparable quadriceps muscle EMG activity compared with traditional machine-based exercise, irrespective of age. • Elastic band resistance exercise may represent a novel exercise modality in facilitating muscular adaptation in older adults. • Bodyweight resistance exercise evokes lower muscle activity compared with elastic based and machine-based exercise, however, may still provide a potent resistance exercise stimulus for older adults.
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- 2020
9. Pre-Sleep Casein Protein Ingestion Does Not Impact Next-Day Appetite, Energy Intake and Metabolism in Older Individuals
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Benoit Smeuninx, Molly Perkins, Leigh Breen, Paul T. Morgan, and Stephen Morehen
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Blood Glucose ,Leptin ,Male ,0301 basic medicine ,Time Factors ,medicine.medical_treatment ,media_common.quotation_subject ,Appetite ,Physiology ,pre-sleep protein ,030209 endocrinology & metabolism ,lcsh:TX341-641 ,Placebo ,Article ,Beverages ,sarcopenia ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Insulin ,Single-Blind Method ,Aged ,Breakfast ,media_common ,Cross-Over Studies ,030109 nutrition & dietetics ,Nutrition and Dietetics ,business.industry ,Caseins ,Feeding Behavior ,medicine.disease ,Ghrelin ,Before Bedtime ,Ageing ,ageing ,Sarcopenia ,Basal metabolic rate ,Female ,Basal Metabolism ,Energy Intake ,Energy Metabolism ,Sleep ,business ,lcsh:Nutrition. Foods and food supply ,Food Science - Abstract
Maintaining adequate daily protein intake is important to maintain muscle mass throughout the lifespan. In this regard, the overnight period has been identified as a window of opportunity to increase protein intake in the elderly. However, it is unknown whether pre-sleep protein intake affects next-morning appetite and, consequently, protein intake. Therefore, the purpose of the current study was to investigate the effects of a pre-sleep protein drink on next-morning appetite, energy intake and metabolism. Twelve older individuals (eight males, four females, age: 71.3 ±, 4.2 years) took part in a single-blind randomised cross-over study. After a standardised dinner, participants consumed either a 40-g protein drink, isocaloric maltodextrin drink, or placebo water control before bedtime. Next-morning appetite, energy intake, resting metabolic rate (RMR), respiratory exchange rate (RER), and plasma acylated ghrelin, leptin, glucose, and insulin concentrations were assessed. No between-group differences were observed for appetite and energy intake at breakfast. Furthermore, RMR, RER, and assessed blood markers were not significantly different between any of the treatment groups. Pre-sleep protein intake does not affect next-morning appetite and energy intake and is therefore a viable strategy to increase daily protein intake in an older population.
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- 2019
10. 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
11. 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
12. 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
13. 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
14. 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.
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- 2018
15. Acute ibuprofen ingestion does not attenuate fatigue during maximal intermittent knee extensor or all-out cycling exercise
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Stephen J. Bailey, Andrew M. Jones, Anni Vanhatalo, Joanna L. Bowtell, and Paul T. Morgan
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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.
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- 2018
16. The Effects of β-Alanine Supplementation on Muscle pH and the Power-Duration Relationship during High-Intensity Exercise
- Author
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Anni Vanhatalo, Andrew M. Jones, Matthew I. Black, Stephen J. Bailey, Paul T. Morgan, and Jonathan Fulford
- Subjects
0301 basic medicine ,medicine.medical_specialty ,muscle pH ,Physiology ,Carnosine ,beta-Alanine ,power-duration relationship ,Muscle carnosine ,lcsh:Physiology ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Internal medicine ,Physiology (medical) ,Exercise performance ,medicine ,beta-alanine ,Original Research ,Alanine ,lcsh:QP1-981 ,High intensity ,INT ,030229 sport sciences ,carnosine ,030104 developmental biology ,Endocrinology ,chemistry ,Critical power ,critical power - Abstract
Purpose: To investigate the influence of β-alanine (BA) supplementation on muscle carnosine content, muscle pH and the power-duration relationship (i.e., critical power and W′).Methods: In a double-blind, randomized, placebo-controlled study, 20 recreationally-active males (22 ± 3 y, V°O2peak 3.73 ± 0.44 L·min−1) ingested either BA (6.4 g/d for 28 d) or placebo (PL) (6.4 g/d) for 28 d. Subjects completed an incremental test and two 3-min all-out tests separated by 1-min on a cycle ergometer pre- and post-supplementation. Muscle pH was assessed using 31P-magnetic resonance spectroscopy (MRS) during incremental (INC KEE) and intermittent knee-extension exercise (INT KEE). Muscle carnosine content was determined using 1H-MRS.Results: There were no differences in the change in muscle carnosine content from pre- to post-intervention (PL: 1 ± 16% vs. BA: −4 ± 25%) or in muscle pH during INC KEE or INT KEE (P > 0.05) between PL and BA, but blood pH (PL: −0.06 ± 0.10 vs. BA: 0.09 ± 0.13) during the incremental test was elevated post-supplementation in the BA group only (P < 0.05). The changes from pre- to post-supplementation in critical power (PL: −8 ± 18 W vs. BA: −6 ± 17 W) and W′ (PL: 1.8 ± 3.3 kJ vs. BA: 1.5 ± 1.7 kJ) were not different between groups. No relationships were detected between muscle carnosine content and indices of exercise performance.Conclusions: BA supplementation had no significant effect on muscle carnosine content and no influence on intramuscular pH during incremental or high-intensity intermittent knee-extension exercise. The small increase in blood pH following BA supplementation was not sufficient to significantly alter the power-duration relationship or exercise performance.
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- 2018
- Full Text
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17. 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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