Kazunori Nosaka

Kazunori Nosaka
Edith Cowan University · Centre for Exercise and Sports Science Research (CESSR), School of Medical and Health Sciences

Doctor of Philosophy

About

319
Publications
173,397
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
16,408
Citations

Publications

Publications (319)
Article
Full-text available
Purpose: Eccentric contractions induce muscle damage, but less is known about the effects of preceding concentric contractions to eccentric contractions on muscle damage. We compared eccentric-only (ECC) and coupled concentric and eccentric contractions (CON-ECC) of the knee extensors for parameters of neuromuscular fatigue and muscle damage. Met...
Article
Full-text available
Purpose This study compared concentric–eccentric coupled (CON-ECC), concentric-only (CON), and eccentric-only (ECC) resistance training of the elbow flexors for their effects on muscle strength and hypertrophy. Methods Non-resistance-trained young adults were assigned to one of the four groups: CON-ECC (n = 14), CON (n = 14) and ECC (n = 14) train...
Conference Paper
Full-text available
Book of Abstracts - INTRODUCTION: Children have become less physically active in the last decade, and their muscle force and power levels are lower when compared with the children in ~40 years ago (1). The decrease in physical activity levels seems to have been accentuated due to the COVID-19 pandemic (2), and dynapenia (i.e., loss of muscle force...
Article
Purpose: We examined whether the magnitude of muscle damage indicated by changes in maximal voluntary isometric contraction (MVIC) strength 1 to 3 d after unaccustomed eccentric exercise (ECC) was correlated with changes in central and peripheral neuromuscular parameters immediately post-ECC. Methods: Twenty participants (19–36 yr) performed six se...
Article
Full-text available
The COVID-19 outbreak has led to the implementation of strict restrictions in Australia, which have severely impacted sporting activities. Tennis is played by 6.2% of the population within the Oceania region, and is a valuable sport for maintaining social, mental and physical health. Current literature indicates the COVID-19 pandemic has negatively...
Article
Full-text available
Purpose: This study compared the effects of contralateral eccentric-only (ECC) and concentric-eccentric coupled resistance training (CON-ECC) of the elbow flexors on immobilized arm. Methods: Thirty healthy participants (18-34 y) were randomly allocated to immobilization only (CTRL; n=10), immobilization and ECC (n=10) or immobilization and CON-ECC...
Article
Short-interval intracortical inhibition (SICI) is often assessed to investigate inhibitory responses in the primary motor cortex representation of the quadriceps. However, determining appropriate paired-pulse transcranial magnetic stimulation (TMS) parameters to optimise SICI measurement can be impractical and time-consuming. This study investigate...
Article
Full-text available
Purpose: This study compared the effects of velocity-based training (VBT) and one-repetition maximum (1RM) percent-based training (PBT) on changes in strength, loaded countermovement jump (CMJ) and sprint performance. Methods: Twenty-four resistance-trained males performed 6-weeks of full-depth free-weight back squats 3-times/week in a daily undula...
Article
Full-text available
Purpose We compared high- and low-intensity eccentric cycling (ECC) with the same mechanical work for changes in muscle function and muscle soreness, and examined the changes after subsequent high-intensity ECC. Methods Twenty men performed either high-intensity ECC (1 min × 5 at 20% of peak power output: PPO) for two bouts separated by 2 weeks (H...
Poster
Introduction & Aims: Tensiomyography (TMG) is a non-invasive tool to assess muscle contraction characteristics by recording displacement of the muscle belly (Dm) in evoked twitches. Multiple formulas have been used to estimate TMG-derived contraction velocity (Vc), but the most suitable method is yet to be established. In this study, previously rep...
Article
Full-text available
An emerging field of research is starting to examine the association of infectious pathogens with type 2 diabetes mellitus (T2DM). An understudied parasite of interest is Toxoplasma gondii. Globally, very few studies have been conducted to investigate this association. Additionally, very little data exists on the prevalence of T. gondii in the gene...
Article
Introduction Despite being identified as one of the top neglected parasitic infections, Toxoplasma gondii has received little recognition in Australia with no previously published prevalence data from the general human population. The objectives of the current study were to: determine the prevalence of evidence of exposure to T. gondii infection in...
Conference Paper
Full-text available
Introduction: Short-interval intracortical inhibition (SICI) can be assessed using paired-pulse transcranial magnetic stimulation (TMS), and is thought to provide indices of gaba-amino-butryic-acid (GABAa) mediated inhibition. The present study investigated the reliability and variability across days of SICI measured in the quadriceps. Methods: Fi...
Article
Full-text available
Our group sought to determine the global status of T. gondii infection and to evaluate any continental and geographical trends by systematically examining the currently available epidemiological data on the prevalence of T. gondii infection. A comprehensive literature search was conducted from 10 electronic databases (Google Scholar, Science Direct...
Article
Full-text available
Purpose We examined the effect of muscle stretching on the ability to produce rapid torque and the mechanisms underpinning the changes. Methods Eighteen men performed three conditions: (1) continuous stretch (1 set of 5 min), (2) intermittent stretch (5 sets of 1 min with 15-s inter-stretch interval), and (3) control. Isometric plantar flexor rate...
Article
New findings: What is the central question of this study? Do neural and/or mechanical factors determine the extent of muscle damage induced by eccentric contractions? What is the main finding and its importance? The extent of muscle damage induced by eccentric contractions is related to both mechanical strain and corticospinal excitability measure...
Article
Full-text available
Delgado, J, Drinkwater, EJ, Banyard, HG, Haff, GG, and Nosaka, K. Comparison between back squat, romanian deadlift, and barbell hip thrust for leg and hip muscle activities during hip extension. J Strength Cond Res XX(X): 000-000, 2019-This study compared muscle activities of vastus lateralis (VL), biceps femoris (BF), and gluteus maximus (GM) duri...
Article
Full-text available
Abstract Objective No previous study has compared water and oral rehydration solution (ORS) intake after dehydration induced by exercise in the heat for the effect on muscle cramps. The present study tested the hypothesis that water ingestion after dehydration would increase muscle cramp susceptibility, but this would be prevented by ORS ingestion....
Article
Full-text available
Differences in the neural mechanisms underpinning eccentric (ECC) and concentric (CON) contractions exist; however, the acute effects of fatiguing muscle contractions on intracortical and corticospinal excitability are not well understood. Therefore, we compared maximal ECC and CON contractions of the right biceps brachii (BB) muscle for changes in...
Poster
Full-text available
The modulation of intracortical brain networks following concentric or eccentric contractions in the biceps brachii.
Article
Full-text available
Objectives An emerging field of research is examining the association of infectious and environmental pathogens with type 2 diabetes mellitus (T2DM). An understudied pathogen of interest is the protozoan parasite Toxoplasma gondii ( T. gondii ). The objective of this study was to investigate the possible correlation between T. gondii infection and...
Article
Full-text available
It has been reported that eccentric training of knee extensors is effective for improving blood insulin sensitivity and lipid profiles to a greater extent than concentric training in young women. However, it is not known whether this is also the case for elderly individuals. Thus, the present study tested the hypothesis that eccentric training of t...
Article
Evidence-based guidelines recommend exercise therapy for patients with chronic heart failure (CHF). Such patients have increased atherothrombotic risk. Exercise can transiently increase platelet activation and reactivity and decrease vascular function in healthy participants, although data in CHF is scant. Eccentric (ECC) cycling is a novel exercis...
Article
Full-text available
Purpose Mountain trekking involves level, uphill, and downhill walking (DW). Prolonged DW induces damage to leg muscles, reducing force generating ability and muscle coordination. These increase risks for more serious injuries and accidents in mountain trekking, thus a strategy to minimize muscle damage is warranted. It has been shown that low-inte...
Article
Purpose Mountain trekking involves level, uphill, and downhill walking (DW). Prolonged DW induces damage to leg muscles, reducing force generating ability and muscle coordination. These increase risks for more serious injuries and accidents in mountain trekking, thus a strategy to minimize muscle damage is warranted. It has been shown that low-inte...
Article
Purpose: Eccentric exercise training produces positive fitness and health outcomes, but whether this is also the case for descending stair walking (DSW) is unknown. This study investigated the hypothesis that DSW would improve insulin sensitivity, lipid profiles and physical fitness better than ascending stair walking (ASW). Methods: Elderly (≥6...
Article
Full-text available
Unaccustomed exercise consisting of eccentric (i.e., lengthening) muscle contractions often results in muscle damage characterized by ultrastructural alterations in muscle tissue, clinical signs and symptoms (e.g., reduced muscle strength and range of motion, increased muscle soreness and swelling, efflux of myocellular proteins). The time course o...
Article
Full-text available
PurposeThis study compared maximal eccentric (ECC) and concentric (CON) contractions of the elbow flexors for changes in transverse relaxation time (T2) and indirect markers of muscle damage. Methods Twelve young men performed five sets of six maximal isokinetic (30°/s) ECC with one arm followed by CON with the other arm. Magnetic resonance images...
Article
Full-text available
Type 2 diabetes mellitus (T2DM) continues to be a major challenge for public health authorities worldwide. While potential causes such as obesity, physical inactivity, and dietary patterns have been proposed to explain the growing epidemic, there may also be unidentified environmental determinants. An emerging field of research is starting to exami...
Article
Full-text available
Introduction: Chronic heart failure (CHF) is characterized by dyspnea and poor exercise tolerance, which decreases aerobic capacity (V˙O2peak), a measure strongly correlated with quality of life and mortality. In healthy populations, eccentric (ECC) cycling can be performed at a lower oxygen demand for matched workload, compared to concentric (CON...
Article
Full-text available
Purpose: The purpose of this study was to investigate the effect of three swim pacing profiles on subsequent performance during a sprint distance triathlon (SDT). Methods: Nine competitive/trained male triathletes completed five experimental sessions, including a graded running exhaustion test, a 750 m swim time-trial (STT), and three SDTs. The...
Article
Eccentric exercise training is effective for increasing muscle mass and strength, and improving insulin sensitivity and blood lipid profiles. However, potential muscle damage symptoms such as prolonged loss of muscle function and delayed onset of muscle soreness may restrict the use of eccentric exercise, especially in clinical populations. Therefo...
Article
Skeletal muscle adapts to exercise-induced damage by orchestrating several, but still poorly understood mechanisms that endow protection from subsequent damage. Known widely as the repeated bout effect, we propose that neural adaptations, alterations to muscle mechanical properties, structural remodeling of the extracellular matrix, and biochemical...
Article
This study examined the test-retest reliability of near-infrared spectroscopy (NIRS), laser Doppler flowmetry (LDF) and Doppler ultrasound to assess exercise-induced haemodynamics. Nine men completed two identical trials consisting of 25-min submaximal cycling at first ventilatory threshold followed by repeated 30-s bouts of high-intensity (90% of...
Article
Full-text available
Banyard, HG, Nosaka, K, and Haff, GG. Reliability and validity of the load-velocity relationship to predict the 1RM back squat. J Strength Cond Res 31(7): 1897-1904, 2017-This study investigated the reliability and validity of the load-velocity relationship to predict the free-weight back squat one repetition maximum (1RM). Seventeen strength-train...
Article
This study compared the effect of postexercise water immersion (WI) at different temperatures on common femoral artery blood flow (CFA), muscle (total haemoglobin; tHb) and skin perfusion (cutaneous vascular conductance; CVC), assessed by Doppler ultrasound, near-infrared spectroscopy (NIRS) and laser Doppler flowmetry, respectively. Given that hea...
Article
Purpose: This study compared the effects of isoload (IL) and isokinetic (IK) knee extensor eccentric exercises on changes in muscle damage and neuromuscular parameters to test the hypothesis that the changes would be different after IL and IK exercises. Methods: Twenty-two young men were paired based on their strength and placed to IL (N = 11) o...
Article
This study investigated whether maximal voluntary isometric contractions (MVIC) performed before maximal eccentric contractions (MaxEC) would attenuate muscle damage of the knee extensors. Untrained men were placed to an experimental group that performed 6 sets of 10 MVIC at 90° knee flexion 2 weeks before 6 sets of 10 MaxEC or a control group that...
Article
Background The current study investigated stretch variables and mechanical factors of lengthening contractions (LC) in the processes leading to muscular mechanical hyperalgesia in rats to understand mechanisms underpinning delayed onset muscle soreness (DOMS). Methods Under isoflurane anaesthesia, ankle extensor muscles were loaded with repetitive...
Article
Full-text available
Functional Muscle metabolic demand during contractions evoked by neuromuscular electrical stimulation (NMES) has been consistently documented to be greater than voluntary contractions (VOL) at the same force level (10-50% maximal voluntary contraction-MVC). However, we have shown using a near-infrared spectroscopy (NIRS) technique that local muscle...
Article
Full-text available
To understand the recovery of a top triathlete from Ironman distance triathlon races and the timing of training resumption, this study followed an elite male triathlete for 4 years and examined blood parameters after 6 Ironman triathlon races, in which he finished either first (3 races) or second (3 races), with finishing times of 8:00:21 to 8:49:3...
Article
Full-text available
Purpose: Eccentric contractions (ECCs) induce muscle damage that is indicated by prolonged loss of muscle function and delayed onset muscle soreness. It is possible that ECCs affect motor nerves, and this may contribute to the prolonged decreases in force generating capability. The present study investigated the hypothesis that M-wave latency of b...
Article
Purpose: This study compared the magnitude of the repeated bout effect for different time intervals between two bouts of eccentric exercise of the elbow flexors to better understand the contralateral repeated bout effect (CL-RBE). Methods: Untrained young men (22.0 ± 1.8 y) were allocated to either a control or one of seven CL-RBE groups (n=13/g...
Article
We investigated the responses of indirect markers of exercise-induced muscle damage (EIMD) among a large number of young men (N=286) stratified in clusters based on the largest decrease in maximal voluntary contraction torque (MVC) after an unaccustomed maximal eccentric exercise bout of the elbow flexors. Changes in MVC, muscle soreness (SOR), cre...
Chapter
Time under tension (TUT) is thought as an important mechanical stimulus for strength and hypertrophic adaptation. The purpose of this study was to determine if two training loads (35 and 70 % 1RM) equated by TUT, differed in terms of their kinematic and kinetic characteristics. Twelve recreationally trained men were recruited in this acute randomiz...
Article
Branched-chain amino acids promote muscle-protein synthesis, reduce protein oxidation and have positive effects on mitochondrial biogenesis and reactive oxygen species scavenging. The purpose of the study was to determine the potential benefits of branched-chain amino acids supplementation on changes in force capacities, plasma amino acids concentr...
Article
Full-text available
Background: Resistance exercise is emerging as a potential adjunct therapy to aid in the management of breast cancer-related lymphedema (BCRL). However, the mechanisms underlying the relationships between the acute and long-term benefits of resistance exercise on BCRL are not well understood. Purpose: To examine the acute inflammatory response t...
Article
Full-text available
Context: Delayed-onset muscle soreness (DOMS) is a common muscle pain that many people experience and is often used as a model of acute muscle pain. Researchers have reported the effects of various interventions on DOMS, but different DOMS assessment protocols used in these studies make it difficult to compare the effects. Objective: To investig...
Article
Full-text available
Cold water immersion (CWI) and active recovery (ACT) are frequently used as post-exercise recovery strategies. However, the physiological effects of CWI and ACT after resistance exercise are not well characterized. We examined the effects of CWI and ACT on cardiac output (Q), muscle oxygenation (SmO2) and blood volume (tHb), muscle temperature (Tmu...
Article
Full-text available
One bout of exercise consisting of fast velocity eccentric contractions has been shown to increase muscle protein degradation in rats. The present study tested the hypothesis that muscle atrophy would be induced after four bouts of fast velocity eccentric contractions, but not after four bouts of slow velocity eccentric contractions. Male Wistar ra...
Article
Introduction: In this study we examined changes in fascicle length and pennation of vastus intermedius (VI) and vastus lateralis (VL) from rest to isometric contraction. Methods: Fourteen healthy men performed submaximal (30% and 50% of maximal voluntary contraction; MVC) isometric knee extensions at 60° and 110° knee flexion (0° = full extensio...
Article
This study aimed to investigate the hypothesis that a repeated bout of eccentric exercise (ECC2) would result in smaller increase in the sensitivity of spinal nociceptive system, and smaller decrease in the local muscle blood oxygenation response in both the ipsilateral and the contralateral tibialis anterior muscle (TA) when compared with the init...