John A Hawley

John A Hawley
Australian Catholic University | ACU · Exercise and Nutrition Research Program at the Mary MacKillop Institute for Health Research

BSc(Hons) CertEd MA PhD

About

464
Publications
279,885
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Citations
Introduction
John’s primary research focus includes the interaction of exercise and diet on the regulation of fat and carbohydrate metabolism, particularly within skeletal muscle, the molecular basis of exercise training adaptation and the cellular bases underlying exercise-induced improvements in insulin action.
Additional affiliations
November 2014 - present
Australian Catholic University
Position
  • Professor
November 2013 - December 2017
Liverpool John Moores University
Position
  • Professor
December 1999 - November 2013
RMIT University
Position
  • Head, Exercise Research Group
Education
January 1990 - December 1993
University of Cape Town
Field of study
  • Bioenergetics of Exercise Research Unit
January 1984 - December 1986
Ball State University
Field of study
  • The Human Performance Laboratory
December 1983 - January 1984
Loughborough University
Field of study
  • Department of Education

Publications

Publications (464)
Article
Full-text available
The AMP-activated protein kinase (AMPK) is a central regulator of cellular energy balance and metabolism and binds glycogen, the primary storage form of glucose in liver and skeletal muscle. The effects of disrupting whole-body AMPK-glycogen interactions on exercise capacity and substrate utilization during exercise in vivo remain unknown. We used...
Article
Time-restricted eating (TRE) is a popular dietary strategy that emphasises the timing of meals in alignment with diurnal circadian rhythms, permitting ad libitum energy intake during a restricted (∼8-10 h) eating window each day. Unlike energy-restricted diets or intermittent fasting interventions that focus on weight loss, many of the health-relat...
Article
Purpose: Exercise training is recommended to improve cardiometabolic health and fertility in women with polycystic ovary syndrome (PCOS), yet there are few randomized controlled trials on the effects of different exercise protocols on clinical reproductive outcomes. Our aim was to determine the effect of high-intensity interval training (HIT) on m...
Article
Full-text available
Introduction: Whether short-term, single-mode exercise training can improve physical fitness prior to a period of reduced physical activity (e.g. post-surgery recovery) is not well characterized in clinical populations nor middle-age adults. We investigated skeletal muscle adaptive responses following endurance exercise training (ENT), high-intens...
Article
Full-text available
The AMP-activated protein kinase (AMPK), a central regulator of cellular energy balance and metabolism, binds glycogen via its β subunit. However, the physiological effects of disrupting AMPK-glycogen interactions remain incompletely understood. To chronically disrupt AMPK-glycogen binding, AMPK β double knock-in (DKI) mice were generated with muta...
Article
Full-text available
Aims/hypothesis We determined whether the time of day of exercise training (morning vs evening) would modulate the effects of consumption of a high-fat diet (HFD) on glycaemic control, whole-body health markers and serum metabolomics. Methods In this three-armed parallel-group randomised trial undertaken at a university in Melbourne, Australia, ov...
Article
OBJECTIVE To determine whether interrupting prolonged sitting improves glycemic control and the metabolic profile of free-living adults with obesity. METHODS Sixteen sedentary individuals (10 women/6 men; median [IQR] age 50 [44-53] years, BMI 32 [32-35.8] kg/m ² ) were fitted with continuous glucose and activity monitors for 4 weeks. After a 1-wee...
Article
Exercise training can induce robust changes in mitochondria that are beneficial for a range of metabolic health outcomes. However, a recent study suggests there might be an upper limit to the amount of high-intensity training that can be tolerated before disruptions to mitochondrial function and whole-body metabolic homeostasis occur.
Article
Full-text available
Exercise training in combination with optimal nutritional support is an effective strategy to maintain or increase skeletal muscle mass. A single bout of resistance exercise undertaken with adequate protein availability increases rates of muscle protein synthesis and, when repeated over weeks and months, leads to increased muscle fiber size. While...
Article
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The past decade has witnessed growing scientific and commercial interest in the identification of bioactive oral compounds that mimic or potentiate the effects of exercise, so‐called “exercise pills” or “exercise mimetics.” These compounds have, to date, typically targeted skeletal muscle in an attempt to stimulate some of the adapations to exercis...
Article
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Introduction Overweight and obesity in reproductive-aged women is a global problem due to the increased risk of subfertility, pregnancy complications and cardiometabolic diseases. High-intensity interval training and time-restricted eating are two primary lifestyle interventions that, independently, have positive effects on a range of health outcom...
Article
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Background & aims Guidelines for reducing postprandial blood glucose concentrations include avoiding high glycemic index (GI) foods, such as white potatoes. However, GI testing is often undertaken in the morning with foods consumed in isolation by non-clinical cohorts. We investigated the impact of potato preparation and consumption as part of a mi...
Article
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The proliferation in the rate of diagnosis of obesity and type 2 diabetes mellitus continues unabated, with current recommendations for primary lifestyle changes (i.e. modification to dietary patterns) having a limited impact in reducing the incidence of these metabolic diseases. Part of the reason for the failure to alter nutritional practices is...
Article
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Individuals with type 2 diabetes (T2D) require a long-term dietary strategy for blood glucose management and may benefit from time-restricted eating (TRE, where the duration between the first and last energy intake is restricted to 8–10 h/day). We aimed to determine the feasibility of TRE for individuals with T2D. Participants with T2D (HbA1c >6.5...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Full-text available
Time-restricted feeding (TRF) improves metabolism independent of dietary macronutrient composition or energy restriction. To elucidate mechanisms underpinning the effects of short-term TRF, we investigated skeletal muscle and serum metabolic and transcriptomic profiles from 11 men with overweight/obesity after TRF (8 h day-1) and extended feeding (...
Article
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MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression post-transcriptionally. In women with polycystic ovary syndrome (PCOS), several miRNAs are differentially expressed compared to women without PCOS, suggesting that miRNAs may underpin the pathophysiology of this condition. Exercise training modulates miRNA abundance and is r...
Article
Full-text available
The ongoing global pandemic brought on by the spread of the novel coronavirus SARS-CoV-2 is having profound effects on human health and well-being. With no viable vaccine presently available and the virus being rapidly transmitted, governments and national health authorities have acted swiftly, recommending ‘lockdown’ policies and/or various levels...
Article
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Accumulation of excess saturated free fatty acids such as palmitate (PAL) in skeletal muscle leads to reductions in mitochondrial integrity, cell viability and differentiation. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) counteract PAL-induced lipid accumulation. EPA and DHA, as...
Article
Full-text available
Objective Glycogen is a major energy reserve in liver and skeletal muscle. The master metabolic regulator AMP-activated protein kinase (AMPK) associates with glycogen via its regulatory β subunit carbohydrate-binding module (CBM). However, the physiological role of AMPK-glycogen binding in energy homeostasis has not been investigated in vivo. This...
Article
Full-text available
About one-third of women of reproductive age are obese, predisposing both mother and baby to unfavourable pregnancy outcomes and initiating an intergenerational cycle of chronic metabolic disorders. Here we summarise recent research on the influence of maternal metabolic health on offspring susceptibility to future cardiometabolic diseases. Current...
Article
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Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) originated in China in late 2019 and has since spread rapidly to every continent in the world. This pandemic continues to cause widespread personal suffering, along with severe pressure on medical and health care providers. The symtoms of SARS‐CoV‐2 and the subsequent prognosis is worsene...
Article
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We determined the effects of time-restricted feeding (TRF; 8 h/d) versus extended feeding (EXF; 15 h/d) on 24-h and postprandial metabolism and subjective opinions of TRF in men with overweight/obesity. In a randomized crossover design, 11 sedentary males (age 38 ± 5 y; BMI: 32.2 ± 2.0 kg/m2) completed two isoenergetic diet protocols for 5 days, co...
Article
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Estrogen (E2) and polyunsaturated fatty acids (n-3PUFA) supplements independently support general wellbeing and enhance muscle regeneration in-vivo and myotube formation in-vitro. However, the combined effect of E2 and n-3PUFA on myoblast differentiation is not known. The purpose of the study was to identify whether E2 and n-3PUFA possess a synergi...
Article
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Objectives: To investigate diet-exercise interactions related to bone markers in elite endurance athletes after a 3.5-week ketogenic low-carbohydrate, high-fat (LCHF) diet and subsequent restoration of carbohydrate (CHO) feeding. Methods: World-class race walkers (25 male, 5 female) completed 3.5-weeks of energy-matched (220 kJ·kg·d−1) high CHO (HC...
Article
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This Perspectives for Progress provide a synopsis for the potential of time-restricted eating (TRE) to rescue some of the deleterious effects on circadian biology induced by our modern-day lifestyle. We provide novel insights into the comparative and potential complementary effects of TRE and exercise training on metabolic health.
Article
Exercise is a potent modulator of intestinal microbiota composition and function. In 2019, several studies uncovered biologically important links between skeletal muscle and the gut microbiota, revealing how the gut bacteria respond to an exercise challenge and have reciprocal roles in fuel availability, muscle function and endurance performance. D...
Article
Background & aims: Chronic overconsumption of sugar-sweetened beverages (SSBs) is associated with unfavourable health effects, including promotion of obesity. However, the acute effects of consuming SSBs on glucose and lipid metabolism remain to be characterized in a real-world, post-prandial context of prolonged sitting. We quantified the acute e...
Article
Full-text available
Climate change is a major contributor to annual winter peaks in cardiovascular events across the globe. However, given the paradoxical observation that cardiovascular seasonality is observed in relatively mild as well as cold climates, global warming may not be as positive for the syndrome of heart failure (HF) as some predict. In this article, we...
Article
Background: Peaks and troughs in cardiovascular events correlated with seasonal change is well established from an epidemiological perspective but not a clinical one. Methods: Retrospective analysis of the recruitment, baseline characteristics and outcomes during minimum 12-month exposure to all four seasons in 1598 disease-management trial pati...
Article
High-circulating lipid availability attenuates protein feeding-induced muscle protein synthesis (MPS). Whether the combined effects of exercise and protein ingestion can rescue this inhibition is unknown. In a parallel-groups design, middle-aged sedentary males ( n = 28) matched for fat-free mass and body mass index received a 5-h intravenous infus...
Article
Human physiological responses to heat, cold, hypoxia, microgravity, hyperbaria, hypobaria and fasting are well studied in isolation. However, in the natural world these stressors are often combined or experienced sequentially (Tipton, 2012). Studies examining human responses to these more realistic, yet relatively complex, circumstances remain spar...
Article
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Background We implemented a high-protein diet (2 g·kg⁻¹·d⁻¹) throughout 12 weeks of concurrent exercise training to determine whether interferences to adaptation in muscle hypertrophy, strength and power could be attenuated compared to resistance training alone. Methods Thirty-two recreationally active males (age: 25 ± 5 years, body mass index: 24...
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The exploits of elite athletes delight, frustrate, and confound us as they strive to reach their physiological, psychological, and biomechanical limits. We dissect nutritional approaches to optimal performance, showcasing the contribution of modern sports science to gold medals and world titles. Despite an enduring belief in a single, superior “ath...
Article
From the breakthrough studies of dietary carbohydrate and exercise capacity in the 1960s through to the more recent studies of cellular signaling and the adaptive response to exercise in muscle, it has become apparent that manipulations of dietary fat and carbohydrate within training phases, or in the immediate preparation for competition, can prof...
Article
We provide an overview of groundbreaking studies that laid the foundation for our current understanding of exercise-induced mitochondrial biogenesis and its contribution to human skeletal muscle fitness. We highlight the mechanisms by which skeletal muscle responds to the acute perturbations in cellular energy homeostasis evoked by a single bout of...
Data
List of significant gradient serum metabolites under HFD.
Data
List of significant gradient muscle metabolites under HCD.
Data
List of significantly changed serum metabolites in the morning by nutritional challenges.
Data
List of significant gradient muscle metabolites under HFD.
Data
Figure S1: Experimental overview of human morning-evening metabolomics study. (A and B) Overview of the experimental design. (A) Each participant (n = 8) completed the experimental conditions in a random order. Human subjects consumed HFD and HCD in a randomized, crossover study with a 7-day washout between each dietary challenge. (B) Serum and mus...
Data
List of significant gradient serum metabolites under HCD.
Data
List of significantly changed serum metabolites in the evening by nutritional challenges.
Data
List of significantly changed muscle metabolites in the morning by nutritional challenges.
Data
Characteristics of study participants at baseline.
Data
List of significantly changed muscle metabolites in the evening by nutritional challenges.
Article
Full-text available
We compared the impact of a high versus low energy intake first meal on glucose and insulin responses during prolonged sitting in individuals with prediabetes. Thirteen adults with overweight/obesity and prediabetes (mean ± SD age: 60 ± 6 years, BMI: 33 ± 4 kg/m2; 2 h OGTT: 8.9 ± 1.1 mmol/L) completed two randomised trials: 10 h uninterrupted sitti...
Article
Full-text available
Human skeletal muscle satellite cells are activated in response to both resistance and endurance exercise. It was initially proposed that satellite cell proliferation and differentiation were only required to support resistance exercise-induced hypertrophy. However, satellite cells may also play a role in muscle fibre remodelling after endurance-ba...
Article
Objective Advances in the field of metabolomics and the concomitant development of bioinformatics tools constitute a promising avenue towards the development of precision medicine and personalized profiling for numerous disease states. Studies in animal models have strengthened this concept, but the application in human subjects is scarce. Methods...
Article
The application of molecular techniques to exercise biology has provided novel insight into the complexity and breadth of intracellular signaling networks involved in response to endurance-based exercise. Here we discuss several strategies that have high uptake by athletes and, on mechanistic grounds, have the potential to promote cellular adaptati...
Article
Full-text available
We determined the effects of altering meal timing and diet composition on temporal glucose homeostasis and physical activity measures. Eight sedentary, overweight/obese men (mean ± SD, age: 36 ± 4 years; BMI: 29.8 ± 1.8 kg/m2) completed two × 12-day (12-d) measurement periods, including a 7-d habitual period, and then 5 d of each diet (high-fat die...
Article
Full-text available
A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.
Article
Key points: Strategies to enhance the loss of fat while preserving muscle mass during energy restriction are of great importance to prevent sarcopenia in overweight older adults. We show for the first time that the integrated rate of synthesis of numerous individual contractile, cytosolic and mitochondrial skeletal muscle proteins was increased by...
Article
High-fat, low-carbohydrate (CHO) diets increase whole-body rates of fat oxidation and down-regulate CHO metabolism. We measured substrate utilization and skeletal muscle mitochondrial respiration to determine whether these adaptations are driven by high fat or low CHO availability. In a randomized crossover design, 8 male cyclists consumed 5 d of a...