Paul Laursen

Auckland University of Technology | AUT · Sports Performance Research Institute New Zealand (SPRINZ)

Background: Elite sport is continuously evolving. World records keep falling and athletes from a longer list of countries are involved. Purpose: This commentary was designed to provide insights into present and future trends associated with world-class endurance training based on the perspectives, experience, and knowledge of an expert panel of...

Muscle glycogen state and carbohydrate (CHO) supplementation before and during exercise may impact responses to high-intensity interval training (HIIT). This study determined cardiorespiratory, substrate metabolism, muscle oxygenation, and performance when completing HIIT with or without CHO supplementation in a muscle glycogen depleted state. On t...

Completing selected training sessions with reduced glycogen availability is associated with greater signalling and improved muscle oxidative capacity, although it may impact the overall quality of the session. We examined the effects of low carbohydrate availability on high intensity exercise performance, running economy, critical speed, and substr...

Purpose This randomized controlled parallel-group study examined the effects of a very low-carbohydrate high-fat (VLCHF) diet and high-intensity interval training (HIIT) program over 12-weeks on cardiometabolic risk factors in individuals with overfat constitution. Methods Ninety-one participants out of 109 completed the study. The participants we...

In a relatively short timeframe, millions of deaths and illnesses associated with COVID-19 have been reported, accompanied by substantial economic losses, and overall, negatively impacting society. This experience should serve as a wakeup call to those in public health and healthcare, along with politicians and citizens: COVID-19 is considered a pr...

Purpose: This randomized controlled parallel-group study examined the effects of a very low-carbohydrate high-fat (VLCHF) diet and high-intensity interval training (HIIT) program over 12 weeks on visceral adipose tissue (VAT) and cardiorespiratory fitness (CRF) level in overfat individuals. Methods: Ninety-one participants were randomly allocated t...

Many individual and team sport events require extended periods of exercise above the speed or power associated with maximal oxygen uptake (i.e., maximal aerobic speed/power, MAS/MAP). In the absence of valid and reliable measures of anaerobic metabolism, the anaerobic speed/power reserve (ASR/APR) concept, defined as the difference between an athle...

A methodology to study bike handling of cyclists during individual time trials (ITT) is presented. Lateral and longitudinal accelerations were estimated from GPS data of professional cyclists (n=53) racing in two ITT of different length and technical content. Acceleration points were plotted on a plot (g-g diagram) and they were enclosed in an elli...

This study aimed to investigate the effect of a 12-week very low-carbohydrate, high-fat (VLCHF) diet and exercise on biomarkers of inflammation in healthy individuals. Since the anti-inflammatory effects of a ketogenic diet have been established, we hypothesized that the VLCHF diet, along with exercise, would have an additional favorable effect on...

The earliest humans relied on large quantities of metabolic energy from the oxidation of fatty acids to develop larger brains and bodies, prevent and reduce disease risk, extend longevity, in addition to other benefits. This was enabled through the consumption of a high fat and low-carbohydrate diet (LCD). Increased fat oxidation also supported dai...

Measurement of oxygen uptake during exercise (V˙O2) is currently non-accessible to most individuals without expensive and invasive equipment. The goal of this pilot study was to estimate cycling V˙O2 from easy-to-obtain inputs, such as heart rate, mechanical power output, cadence and respiratory frequency. To this end, a recurrent neural network wa...

The previously described overfat pandemic, estimated to be 62–76% worldwide, is comprised of individuals with excess body fat sufficient to impair health. The overfat condition is common in those who are overweight and obese, and can also occur in significant numbers of normal-weight non-obese individuals. Being overfat increases the risk for a wid...

Background It is commonly assumed that increased dietary fat and/or caloric excess induces chronic inflammatory processes, since the association between obesity and chronic adipose tissue with systemic inflammation has been shown previously. As far as we know, the reported health benefits of a VLCHF or ketogenic diet have not adequately involved an...

Purpose Bioenergetic models are used in cycling to estimate the acute physiological response in terms of oxygen consumption (\({\dot{\text{V}}}\)O2) and lactate concentration ([La]). First, our aim is to review the bioenergetic modelling literature, presenting historical evolution of concepts, techniques and related limitations. Second, our aim is...

Purpose: The aim of this non-randomized parallel group study was to examine the 12 week effects of a very low-carbohydrate high-fat diet (VLCHF) on maximal cardiorespiratory capacity, high-intensity interval training (HIIT) performance, and cardiac autonomic regulation. Methods: Twenty-four recreationally trained participants allocated to either...

Recent evidence indicates that the modern-day men’s 800 m runner requires a speed capability beyond that of previous eras. In addition, the appreciation of different athlete subgroups (400–800, 800, 800–1500 m) implies a complex interplay between the mechanical (aerial or terrestrial) and physiological characteristics that enable success in any ind...

First and second ventilatory thresholds (VT1 and VT2) represent the boundaries of the moderate-heavy and heavy-severe exercise intensity. Currently, VTs are primarily detected visually from cardiopulmonary exercise test (CPET) data, beginning with an initial data screening followed by data processing and statistical analysis. Automated VT detection...

Purpose: To investigate the effects of short-term, high-intensity interval-training (HIIT) heat acclimation (HA). Methods: Male cyclists/triathletes were assigned into either an HA (n = 13) or a comparison (COMP, n = 10) group. HA completed 3 cycling heat stress tests (HSTs) to exhaustion (60% Wmax; HST1, pre-HA; HST2, post-HA; HST3, 7 d post-HA...

Purpose The anaerobic speed reserve (ASR) defined as the speed range from vVO 2 max to maximal sprint speed (MSS) has recently been shown to be an important tool for middle-distance coaches to meet event surge demands and inform on the complexity of athlete profiles. To enable field application of ASR, the relationship between gun-to tape 1500 m av...

This study investigated the effect of the racemic β-hydroxybutyrate (βHB) precursor, R,S-1,3-butanediol (BD), on time-trial (TT) performance and tolerability. A repeated-measures, randomized, crossover study was conducted in nine trained male cyclists (age, 26.7 ± 5.2 years; body mass, 69.6 ± 8.4 kg; height, 1.82 ± 0.09 m; body mass index, 21.2 ± 1...

The popularity of high-intensity interval training (HIIT), which consists primarily of repeated bursts of high-intensity exercise, continues to soar because its effectiveness and efficiency have been proven in use by both elite athletes and general fitness enthusiasts. Surprisingly, few resources have attempted to explain both the science behind th...

The popularity of high-intensity interval training (HIIT), which consists primarily of repeated bursts of high-intensity exercise, continues to soar because its effectiveness and efficiency have been proven in use by both elite athletes and general fitness enthusiasts. Surprisingly, few resources have attempted to explain both the science behind th...

The popularity of high-intensity interval training (HIIT), which consists primarily of repeated bursts of high-intensity exercise, continues to soar because its effectiveness and efficiency have been proven in use by both elite athletes and general fitness enthusiasts. Surprisingly, few resources have attempted to explain both the science behind th...

The popularity of high-intensity interval training (HIIT), which consists primarily of repeated bursts of high-intensity exercise, continues to soar because its effectiveness and efficiency have been proven in use by both elite athletes and general fitness enthusiasts. Surprisingly, few resources have attempted to explain both the science behind th...

The popularity of high-intensity interval training (HIIT), which consists primarily of repeated bursts of high-intensity exercise, continues to soar because its effectiveness and efficiency have been proven in use by both elite athletes and general fitness enthusiasts. Surprisingly, few resources have attempted to explain both the science behind th...

The popularity of high-intensity interval training (HIIT), which consists primarily of repeated bursts of high-intensity exercise, continues to soar because its effectiveness and efficiency have been proven in use by both elite athletes and general fitness enthusiasts. Surprisingly, few resources have attempted to explain both the science behind th...

The popularity of high-intensity interval training (HIIT), which consists primarily of repeated bursts of high-intensity exercise, continues to soar because its effectiveness and efficiency have been proven in use by both elite athletes and general fitness enthusiasts. Surprisingly, few resources have attempted to explain both the science behind th...

The popularity of high-intensity interval training (HIIT), which consists primarily of repeated bursts of high-intensity exercise, continues to soar because its effectiveness and efficiency have been proven in use by both elite athletes and general fitness enthusiasts. Surprisingly, few resources have attempted to explain both the science behind th...

The popularity of high-intensity interval training (HIIT), which consists primarily of repeated bursts of high-intensity exercise, continues to soar because its effectiveness and efficiency have been proven in use by both elite athletes and general fitness enthusiasts. Surprisingly, few resources have attempted to explain both the science behind th...

The popularity of high-intensity interval training (HIIT), which consists primarily of repeated bursts of high-intensity exercise, continues to soar because its effectiveness and efficiency have been proven in use by both elite athletes and general fitness enthusiasts. Surprisingly, few resources have attempted to explain both the science behind th...

The popularity of high-intensity interval training (HIIT), which consists primarily of repeated bursts of high-intensity exercise, continues to soar because its effectiveness and efficiency have been proven in use by both elite athletes and general fitness enthusiasts. Surprisingly, few resources have attempted to explain both the science behind th...

Objectives Ingested ketogenic agents offer the potential to enhance endurance performance via the provision of an alternative exogenous, metabolically efficient, glycogen-sparing fuel (i.e. ketone bodies). This study aimed to assess the impact of combined carbohydrate and 1,3-butanediol (CHO-BD) supplementation on endurance performance, blood beta-...

Purpose:: In recent years (2011-2016), men's 800m championship running performances have required greater speed than previous eras (2000-2009). The "Anaerobic speed reserve" (ASR) may be a key differentiator of this performance, but profiles of elite 800m runners and its relationship to performance time have yet to be determined. Methods:: The A...

This investigation assessed performance, physiological and perceptual responses to wearing additional clothing during endurance training for two-weeks in temperate environments, to determine if this approach could be used as a practical, alternative, heat acclimation strategy for athletes. Fifteen trained male triathletes assigned to performance-ma...

Performance in motorcycle road racing is typically considered as the summation of interactions between rider, motorcycle, tires, and environment. Despite the substantial investments made towards the development of motorcycle technology and the business interests of manufacturers, published research focusing on the riders is relatively sparse, and a...

The purpose of the study was to examine the effects of altering from habitual mixed Western-based (HD) to a very low-carbohydrate high-fat (VLCHF) diet over a 4-week timecourse on performance and physiological responses during high-intensity interval training (HIIT). Eighteen moderately trained males (age 23.8 ± 2.1 years) consuming their HD (48 ±...

Commentaries on Viewpoint: Resistance training and exercise tolerance during high-intensity exercise: moving beyond just running economy and muscle strength

The overfat condition is defined as excess body fat sufficient to impair health. The problem exists in most overweight and obese individuals and can also occur in those who are normal-weight and non-obese, often due to excess abdominal fat. Despite previous indications that the prevalence overweight and obesity is leveling, these conditions are cur...

Purpose: To determine the effects of heated resistance exercise on thermal strain, neuromuscular function and hormonal responses in power athletes. Methods: Sixteen (n = 8 female; 8 male) highly trained power athletes completed a combined strength and power resistance exercise session in hot (HOT ~30 °C) and temperate (CON ~20 °C) conditions. Hu...

Aim: Machine-learning technologies like Multi Layer Perceptron (MLP) can help to estimate physiological variables that typically require exotic hardware [1]. For instance, direct measurement of oxygen uptake (VO 2) is practically unattainable during outdoor cycling exercise. Using an Artificial Intelligence approach, the aim of our project was to p...

The purpose of this study was to compare the training intensity distribution (TID) of the undefeated world champion male rowing New Zealand (kiwi) pair over a four-year Olympic cycle, across training phases, training years, and between individuals. Training data, including heart rate and boat speed, were recorded in the athletes rowing in the same...

This investigation assessed the acute physiological and perceptual responses to wearing additional clothing during outdoor cycling to determine if this strategy could increase the heat load while training in temperate environments. Seven male cyclists (age: 32 ± 13 y, height: 179 ± 10 cm, body mass: 74 ± 10 kg, body fat percentage: 10.3 ± 1.0%) com...

The Boston Marathon course is deemed ineligible for world record status due to its unidirectional nature and excessive negative elevation change, yet performance times across the World Marathon Majors (WMM) races have not been compared. Purpose To compare finish times across WMM races for Boston, London, Berlin, Chicago and New York Marathons. Me...

Editorial-The Boston Marathon: Time to be record-eligible. (DOCX)

Data underlying results, analysis, and figures. (ZIP)

As major sporting events are often held in hot environments, increased interest in ways of optimally heat acclimating athletes to maximise performance has emerged. Heat acclimation involves repeated exercise sessions in hot conditions that induce physiological and thermoregulatory adaptations that attenuate heat-induced performance impairments. Cur...

While most endurance athletes and coaches recommend higher training loads and high-carbohydrate low-fat diets, some studies report benefits of lower intensity training for performance improvements and a low-carbohydrate high-fat eating plan. We present the case of a 38-year-old female professional/elite Ironman triathlete who presented with decreas...

The global overfat pandemic is a serious public health crisis that places a substantial burden on economic resources in developed countries. The term overfat refers to the presence of excess body fat that can impair health, even for normal weight non-obese individuals. Excess body fat is associated with cardiometabolic dysfunction, a clinical situa...

Manoeuvring a motorcycle at high-speed in official competition has been shown to expose riders to substantial and complex physiological and psychological demands, however few studies have analysed the physical load experienced by professional racers. This study aimed to quantify the physical stress experienced by riders and explore relationships be...

The purpose of the present study was to examine the effects of an oral β-hydroxybutyrate (BHB) supplement on cycling performance. Using a double-blind, placebo-controlled, crossover design, 12 highly-trained cyclists (mean ± SD: age; 35 ± 8 y, mass; 74.5 ± 7.6 kg, VO2peak; 68.0 ± 6.7 ml.min-1kg-1) were supplemented with two 30 ml servings of an ora...

Purpose: To assess the longitudinal evolution of tactical behaviours used to medal in Men's 800m (M800) Olympic Games (OG) or World Championship (WC) events in the recent competition era (2000-2016). Methods: Thirteen OG and WC events were characterised for first and second lap splits using available footage from YouTube. Positive pacing strateg...

Purpose: The aim of this study was to determine the effect of NO3(-) consumption on measures of perception, thermoregulation and cycling performance in hot conditions. Methods: Using a randomised, double-blind, crossover-design, 8 well-trained cyclists (mean ± SD: age: 25 ± 8 y, V̇O2peak: 64 ± 5 ml·kg(-1)·min(-1)) performed 2 separate trials, in...

Purpose: To establish the validity of smartphone photoplethysmography (PPG) and heart rate sensor in the measurement of heart rate variability (HRV). Methods: 29 healthy subjects were measured at rest during 5 min of guided breathing (GB) and normal breathing (NB) using Smartphone PPG, heart rate chest strap and electrocardiography (ECG). The ro...

For the first time in human history, the number of obese people worldwide now exceeds those who are underweight. However, it is possible that there is an even more serious problem—an overfat pandemic comprised of people who exhibit metabolic health impairments associated with excess fat mass relative to lean body mass. Many overfat individuals, how...

Finally, the authoritative resource that serious cyclists have been waiting for has arrived. The perfect blend of science and application, Cycling Science takes you inside the sport, into the training room and research lab, and onto the course. A remarkable achievement, Cycling Science features the following: Contributions from 43 top cycling scien...

We aimed to compare the effects of two different dosing durations of dietary nitrate (NO3-) supplementation on 1- and 4km cycling time-trial performance in highly-trained cyclists. In a double-blind crossover-design, nine highly-trained cyclists ingested 140ml of NO3--rich beetroot juice containing ~8.0mmol [NO3-], or placebo, for seven days. Parti...

Purpose: Heart rate variability (HRV) is a popular tool for monitoring autonomic nervous system status and training adaptation in athletes. It is believed that increases in HRV indicate effective training adaptation, but these are not always apparent in elite athletes. Methods: Resting HRV was recorded in 4 elite rowers (Rower A, B, C and D) ove...

Purpose: To determine the effect of dietary nitrate (NO3(-)) supplementation on physiology and performance in well-trained cyclists following six to eight-days of NO3(-) supplementation. Methods: Eight competitive male cyclists (mean ± SD; age = 26 ± 8 y; body mass = 76.7 ± 6.9 kg; VO2peak = 63 ± 4 ml.kg(-1).min(-1)) participated in a double-bli...

While the words " fit " and " healthy " are often used synonymously in everyday language, the terms have entirely separate meanings. Fitness describes the ability to perform a given exercise task, and health explains a person's state of well-being, where physiological systems work in harmony. Although we typically view athletes as fit and healthy,...

Purpose : To examine the retention and re-acclimation responses during a periodized heat acclimation (HA) protocol in elite sailors preparing for the 2013 World Championships in Muscat, Oman (∼27-30°C, 40-60% RH). Methods : Two elite male Laser class sailors completed 5 consecutive days of HA (60 min per day in 35°C, 60% RH). Heat response tests (...

Purpose: To compare the physiological and performance effects of ad libitum cold fluid (CF) and ice slurry (IS) ingestion on cycling time-trial (TT) performance in the heat. Methods: Seven well-trained male triathletes and cyclists completed two maximal-effort 40-km cycling TT's in hot (35°C) and humid (60% rH) conditions. In randomised order, p...

Miners in Australia frequently perform physically demanding work under high ambient temperatures and humidity, often whilst wearing personal protective equipment, leading to heat-related illnesses. This study investigated effects of replacing 100% and 50% sweat losses with 5% carbohydrate liquid or ice-slurry solution on core temperature during sim...

The cardiorespiratory, cardiac autonomic (via heart rate variability (HRV)) and plasma volume responses to varying sequences of high-intensity interval training (HIT) of consistent external work were investigated. Twelve moderately trained males underwent three HIT bouts and one control session. The HIT trials consisted of warm-up, followed by 12 m...

Background: Although carbohydrate is the predominant fuel source supporting high-intensity exercise workloads, the role of fat oxidation, and the degree to which it may be altered by training status, is less certain. Methods: We compared substrate oxidation rates, using indirect calorimetry, during a high-intensity interval training (HIT) session i...

h2>Introduction The purpose of this investigation was to evaluate the physical characteristics of a group of West Australian male paramedics. Methods Data was collected from conventional (CO) (n=18) and special operations (SO) (n=11) officers undergoing occupational performance evaluations as contracted by St. John Ambulance Australia to an exte...

The oral presence of carbohydrate (CHO) and caffeine (CAF) may independently enhance exercise performance, but their influence on performance during prolonged exercise is less known. To determine the independent and combined effects of CHO and CAF administered in chewing gum during a cycling time-trial (TT) following prolonged exercise. Eleven male...