Nicholas B. Tiller

Lundquist Institute at Harbor-UCLA Medical Center · Institute of Respiratory Medicine and Exercise Physiology

Purpose Diaphragm and abdominal muscles are susceptible to contractile fatigue in response to high-intensity, whole-body exercise. This study assessed whether the ventilatory and mechanical loads imposed by high-intensity, upper-body exercise would be sufficient to elicit respiratory muscle fatigue. Methods Seven healthy men (mean ± SD; age = 24 ±...

New findings: What is the central question of this study? To what extent are the mechanical-ventilatory responses to upper-body exercise influenced by task-specific locomotor mechanics? What is the main finding and its importance? When compared with lower-body exercise performed at similar ventilations, upper-body exercise was characterized by tid...

In this Position Statement, the International Society of Sports Nutrition (ISSN) provides an objective and critical review of the literature pertinent to nutritional considerations for training and racing in single-stage ultra-marathon. Recommendations for Training. i) Ultra-marathon runners should aim to meet the caloric demands of training by fol...

Ultra-endurance has been defined as any exercise bout that exceeds 6 h. A number of exceptional, record-breaking performances by female athletes in ultra-endurance sport has roused speculation that they might be predisposed to success in such events. Indeed, while the male-to-female performance gap in traditional endurance sport (e.g., marathon) re...

The global health and wellness industry has an estimated value of US$4 trillion. Profits derive from heath club memberships, exercise classes, diets, supplements, alternative ‘therapies’, and thousands of other products and services that are purported to improve health, recovery, and/or sports performance. The industry has expanded at an alarming r...

The literature on high-intensity interval training (HIIT) contains claims that, if true, could revolutionize the science and practice of exercise. This critical analysis examines two varieties of claims: (i) HIIT is effective in improving various indices of fitness and health, and (ii) HIIT is as effective as more time-consuming moderate-intensity...

Increasing transparency and openness in science is an ongoing endeavor, one that has stimulated self-reflection and reform in many fields. However, kinesiology and its related disciplines are among those exhibiting an "ostrich effect" and a reluctance to acknowledge their methodological shortcomings. Notwithstanding several high-profile cases of sc...

Respiratory function has become a global health priority. Not only is chronic respiratory disease a leading cause of worldwide morbidity and mortality, but the COVID-19 pandemic has heightened attention on respiratory health and the means of enhancing it. Subsequently, and inevitably, the respiratory system has become a target of the multi-trillion...

A routine clinical assessment in a 39-year-old male revealed liver function tests at 1.4-2.3 times the normal limit. He was asymptomatic, had no personal/family history of liver disease, and did not drink or use recreational drugs. He was in good physical condition and engaged in regular running and resistance exercise. Negative workup included tes...

Introduction: Several studies report that pulmonary oxygen uptake (V̇O2) at the respiratory compensation point (RCP) is equivalent to the V̇O2 at critical power (CP), suggesting that the variables can be used interchangeably to demarcate the threshold between heavy and severe intensity domains. But if RCP is a valid surrogate for CP, their values...

Introduction: Severe chronic obstructive pulmonary disease (COPD) is partly characterized by diminished skeletal muscle oxidative capacity and concurrent dyslipidemia. It is unknown whether such metabolic derangements increase the risk of cardiovascular disease. This study explored associations among physical activity (PA), muscle oxidative capaci...

Purpose: Despite a growing body of literature on the physiological responses to ultramarathon, there is a paucity of data in females. This study assessed the female physiological response to ultramarathon and compared the frequency of perturbations to a group of race- and time-matched males. Methods: Data were collected from 53 contestants of an...

It is well established that physical activity reduces all-cause mortality and can prolong life. Ultra-endurance running (UER) is an extreme sport that is becoming increasingly popular, and comprises running races above marathon distance, exceeding 6-hours, and/or running fixed distances on multiple days. Serious acute adverse events are rare but th...

Background Lower heart rate (HR) increases during exercise and slower HR recovery (HRR) after exercise are markers of worse autonomic function that may be associated with risk of acute respiratory events (ARE). Methods Data from 6-min walk testing (6MWT) in COPDGene were used to calculate the chronotropic index (CI) [(HR immediately post 6MWT – re...

Dear Editor, We really appreciate the Letter to the Editor by Jouffroy and colleagues [1], which added valuable information and discussion to our narrative review titled “Potential Long- Term Health Problems Associated with Ultra-Endurance Running” [2]. One of the primary aims of the paper was to “stimulate more open debate about the potential impl...

Dishman challenged kinesiologists to seek a compromise between “the ideal physiological prescription and a manageable behavioral prescription.” High-intensity interval training (HIIT) is the first exercise modality that has been claimed to meet this challenge, combining substantial benefits for fitness and health with pleasure and enjoyment. If tru...

Background: Slow heart rate recovery (HRR) after exercise is associated with autonomic dysfunction and increased mortality. What HRR criterion at 1-minute after a 6-minute walk test (6MWT) best defines pulmonary impairment?. Study design and methods: A total of 5008 phase 2 COPDGene (NCT00608764) participants with smoking history were included....

Objectives Compliant surfaces beneath a casualty diminish the quality of cardiopulmonary resuscitation (CPR) in clinical environments. To examine this issue in a sporting environment, we assessed chest compression quality and rescuer exertion upon compliant sports safety matting. Methods Twenty-seven advanced life support providers volunteered (13...

Introduction: Assessing airway function during exercise provides useful information regarding mechanical properties of the airways and extent of ventilatory limitation in COPD. The primary aim of this study was to use impulse oscillometry (IOS) to assess dynamic changes in airway impedance across a range of exercise intensities in GOLD 1-4 patient...

Physical exertion was once crucial for survival because energy (food) was derived predominantly from hunting and foraging; this, in turn, shaped the genome of modern man. In contemporary society, human genes and human lives are incongruent; physical activity is no longer a prerequisite for securing calories, our jobs are largely sedentary, and scar...

Introduction Drinking cold water evokes decreases in spirometric indices of lung function. We studied whether this could be explained by changes in exhaled-breath temperature (EBT), airflow dynamics, and spirometer measurement sensitivity. Methods In a randomized/crossover design, 10 healthy adults consumed 1000 mL refrigerated water (2.1 ± 0.64 °...

Rock climbing has become a mainstream sport, contested on the Olympic stage. The work/rest pattern of bouldering is unique among disciplines, and little is known about its physiological demands. This study characterised the cardiorespiratory responses to simulated competition. Eleven elite boulderers (7 male) volunteered to participate (age = 23.3...

Introduction: This paper assessed the blood pressure, heart rate, and mouth-pressure responses to indoor rock climbing (bouldering) and associated training exercises. Case presentation: Six well-trained male rock climbers (mean ± SD age = 27.7 ± 4.7 y; stature = 177.7 ± 7.3 cm; mass = 69.8 ± 12.1 kg) completed two boulder problems (6b and 7a+ on...

Regular physical activity decreases the risk of cardiovascular disease, type II diabetes, obesity, certain cancers, and all-cause mortality. Nevertheless, there is mounting evidence that extreme exercise behaviors may be detrimental to human health. This review collates several decades of literature on the physiology and pathophysiology of ultra-ma...

PURPOSE: Ingesting cold-water evokes decreases in spirometric indices of pulmonary function. However, given that most commercial spirometers assume an exhaled-breath temperature (EBT) of 37 °C, a cold-water-induced decrease in EBT may influence the accuracy of flow-volume measurements. Accordingly, the aims of this study were: i) to assess whether...

PURPOSE: Strenuous exercise performed at altitude increases cardiac output and pulmonary arterial and capillary pressures to levels that may exceed a tolerable alveolar-capillary load, thereby evoking fluid leakage into the interstitial space. Accordingly, this study aimed to determine whether running an ultramarathon at moderate altitude increases...

The physiological demands of marathon and ultra-marathon running are substantial, affecting multiple body systems. There have been several reviews on the physiological contraindications of participation; nevertheless, the respiratory implications have received relatively little attention. This paper provides an up-to-date review of the literature p...

PURPOSE: This case-report characterised the respiratory, cardiovascular, and nutritional/gastrointestinal (GI) responses of a trained individual to a novel ultra-endurance exercise challenge. METHODS: A male athlete (age 45 y, mass 80.7 kg, stature 1.71 m, V̇O2max 54.8 mL∙kg-1∙min-1) summited 100 mountains on foot (all elevations >600 m) in 25 con...

Background: This case-report characterized the respiratory, cardiovascular, and nutritional/gastrointestinal (GI) responses of a trained individual to a novel ultra-endurance exercise challenge. Case Presentation: A male athlete (age 45 years; V ˙ O2max 54.0 mL⋅kg-1⋅min-1) summited 100 mountains on foot in 25 consecutive days (all elevations >60...

Purpose Marathon and ultramarathon provoke respiratory muscle fatigue and pulmonary dysfunction; nevertheless, it is unknown how the respiratory system responds to multiple, consecutive days of endurance exercise. Methods Nine trained individuals (six male) contested 10 marathons in 10 consecutive days. Respiratory muscle strength (maximum static...

Objective: Due to the high intra-thoracic pressures associated with forced vital capacity manoeuvres, spirometry is contraindicated for vulnerable patients. However, the typical pressure response to spirometry has not been reported. Eight healthy, recreationally-active men performed spirometry while oesophageal pressure was recorded using a latex...

Drawing on reflections from a collaborative autoethnography, this article argues that ultramarathon running is defined by a ‘dark’ ecological sensibility [Morton, Timothy. 2007. Ecology without Nature. London: Harvard University Press; Morton, Timothy. 2010. The Ecological Thought. London: Harvard University Press; Morton, Timothy. 2016. Dark Ecolo...

Background The purpose of this paper was to report normative data on regional sweat sweat-sodium concentrations of various professional male team-sport athletes, and to compare sweat-sodium concentrations among sports. Data to this effect would inform our understanding of athlete sodium requirements, thus allowing for the individualisation of sodiu...

Introduction: The aim of this case report was to determine whether maximal upper-body exercise was sufficient to induce diaphragm fatigue in a Paralympic champion adaptive rower with low-lesion spinal cord injury (SCI). Case presentation: An elite arms-only oarsman (age 28 y, stature 1.89 m, mass 90.4 kg) with motor-complete SCI (T12) performed...

IntroductionAsynchronous arm-cranking performed at high cadences elicits greater cardiorespiratory responses compared to low cadences. This has been attributed to increased postural demand and locomotor–respiratory coupling (LRC), and yet, this has not been empirically tested. This study aimed to assess the effects of cadence on cardiorespiratory r...

Numerous studies have examined the multifarious effects of music applied during exercise but few have assessed the efficacy of music as an aid to recovery. Music might facilitate physiological recovery via the entrainment of respiratory rhythms with music tempo. High-intensity exercise training is not typically associated with positive affective re...

Numerous studies have examined the multifarious effects of music applied during exercise but few have assessed the efficacy of music as an aid to recovery. Music might facilitate physiological recovery via the entrainment of respiratory rhythms with music tempo. High-intensity exercise training is not typically associated with positive affective re...

Introduction: The diaphragm and abdominal muscles exhibit contractile fatigue in response to sustained, high-intensity, whole-body exercise. We hypothesized that upper-body exercise would increase the contribution of the thoracic muscles to the control of trunk stability, and leave the diaphragm and abdominal muscles susceptible to contractile fati...

The aim of this case report was to determine whether maximal upper body exercise was sufficient to induce diaphragm fatigue in a Paralympic champion adaptive rower with low-lesion spinal cord injury (SCI). An elite arms-only oarsman (age: 28 yr; stature: 1.89 m; and mass: 90.4 kg) with motor-complete SCI (T12) performed a 1,000-m time trial on an a...

Introduction Asynchronous arm-cranking performed at high cadences elicits greater cardiorespiratory responses compared to low cadences. This has been attributed to increased postural demand and locomotor–respiratory coupling (LRC), and yet, this has not been empirically tested. This study aimed to assess the effects of cadence on cardiorespiratory...

Introduction: There are unequivocal differences in the cardiorespiratory response to exercise performed with the upper-limbs compared to the lower-limbs, but the mechanical-ventilatory responses to exercise have not been systematically studied. Aim: To assess mechanical-ventilatory and perceptual responses to upper- vs. lower-body exercise in healt...