Kazunori Nosaka

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

- ABSTRACT - Background: A significant decline in physical activity levels of children and adolescents has been reported over the last decades, and it appears that the magnitude of decrease in physical activity levels was accentuated during and after the COVID-19 pandemic. This has resulted in children having health problems that were traditionall...

INTRODUCTION: Eccentric (ECC) cycling allows greater mechanical load to be achieved despite lower metabolic demand [1] and induces different acute cardiorespiratory and neuromuscular responses than those observed during conventional concentric (CON) cycling [2-3]. The present study aimed to determine how pedal cadence and blood flow restriction (BF...

The purpose of this article is to introduce the Brief Emotional Experience Scale (BEES) as a measure for mood monitoring. To assess the utility of the BEES as a measure for mood monitoring, 95 participants filled out the BEES three times per day for seven consecutive days while also indicating if they had experienced positive and/or negative events...

Many individuals do not participate in resistance exercise, with perceived lack of time being a key barrier. Minimal dose strategies, which generally reduce weekly exercise volumes to less than recommended guidelines, might improve muscle strength with minimal time investment. However, minimal dose strategies and their effects on muscle strength ar...

Purpose Many modern-day children are at risk of pediatric dynapenia (muscle weakness). We examined the effects of a 12-week resistance training (RT) program on neuromuscular function and body composition parameters in pubertal children with a risk of dynapenia. Methods Twelve children (13.4 ± 0.9 y) with dynapenia performed a progressive RT progra...

Aims Eccentric exercise (ECC) is a potentially effective exercise therapy modality during cancer, due to its effectiveness at improving muscle mass and architecture, body composition, and metabolic markers which are often impaired during cancer disease and treatments, at lower efforts and cardiovascular demands compared to conventional exercises (...

Different methods can be used to assess muscle hypertrophy, but the effects of training on regional changes in muscle size can be detected only using direct muscle measurementssuch as muscle thickness, cross-sectional area, or volume. Importantly, muscle size increases vary across regions both within and between muscles following resistance trainin...

The maximal number of repetitions that can be completed at various percentages of the one repetition maximum (1RM) [REPS ~ %1RM relationship] is foundational knowledge in resistance exercise programming. The current REPS ~ %1RM relationship is based on few studies and has not incorporated uncertainty into estimations or accounted for between-indivi...

INTRODUCTION: Eccentric cycling training has been reported to increase muscle mass and function at low efforts [1], but the optimal protocols for eccentric cycling training are yet to be established. Previous studies prescribed eccentric cycling based on heart rate, oxygen consumption, or perceived effort [1-3]. However, a protocol based on maximal...

Introduction: Eccentric-overload (EO) resistance training emerges as an alternative to more optimally prescribe intensity relative to the force generation capabilities of the eccentric muscle contraction. Given the difficulties to individually prescribe absolute eccentric loads relative to each person’s eccentric ability, setting the load relative...

PURPOSE: The study compared the efficacy of commencing supervised exercise in men with prostate cancer before (Prehab) and after (Rehab) prostatectomy on objective and patient-reported outcomes, hospital length of stay (LOS), and urinary incontinence (UI). METHODS: Forty-one men were randomised to a 6-week Prehab or Rehab exercise programme. Prehab...

Since the 1970s, researchers have studied a potential difference in muscle fatigue (acute strength loss) between maximal eccentric (ECCmax) and concentric (CONmax) resistance exercise. However, a clear answer to whether such a difference exists has not been established. Therefore, the aim of our paper was to overview methods and results of studies...

Kotani, Y, Lake, J, Guppy, SN, Poon, W, Nosaka, K, and Haff, GG. Agreement in squat jump force-time characteristics between Smith machine and free-weight squat jump force-time characteristics. J Strength Cond Res XX(X): 000-000, 2023-The purpose of this study was to determine whether squat jump (SJ) force-velocity (FV) and load-velocity (LV) profil...

The maximal number of repetitions that can be completed at various percentages of the one repetition maximum (1RM) (REPS~%1RM relationship) is foundational knowledge in resistance exercise programming. The current REPS~%1RM relationship is based on few studies and has not incorporated uncertainty into estimations or accounted for between-individual...

For decades, researchers have observed that eccentric (ECC) muscle strength is greater than concentric (CON) muscle strength. However, knowledge of the ECC:CON strength ratio is incomplete and might inform resistance exercise prescriptions. Our purposes were to determine the magnitude of the ECC:CON ratio of human skeletal muscle in vivo and explor...

Eccentric resistance exercise emphasizes active muscle lengthening against resistance. In the past 15 years, researchers and practitioners have expressed considerable interest in accentuated eccentric (i.e., eccentric overload) and eccentric-only resistance exercise as strategies for enhancing performance and preventing and rehabilitating injuries....

Oobsolete paper withdrawn

Muscle contraction velocity (Vc) assessed by tensiomyography is a promising measure for athlete profiling. Multiple formulas are used to estimate Vc, but the most suitable method is yet to be established. Fifteen adults (2 female subjects) underwent tensiomyography assessment of biceps brachii muscle at 10, 45 and 90˚of elbow flexion on 2 separate...

Purpose Changes in elbow flexion torque and biceps brachii electromyogram (EMG) activity over 30 repetitive maximal voluntary concentric-only (CON-only), eccentric-only (ECC-only), and alternative concentric and eccentric (CON-ECC, 30 concentric + 30 eccentric) contractions were examined to compare their muscle fatigue profiles. Methods Fifteen he...

Purpose Connected adaptive resistance exercise (CARE) machines are new equipment purported to adjust resistances within and between repetitions to make eccentric (ECC) overload and drop sets more feasible. Here, we examined muscle strength, endurance, electromyographic activity (EMG), and perceptions of fatigue during unilateral bicep curl exercise...

The present study investigated the effects of a far-infrared radiation (FIR) lamp therapy on changes in muscle damage and proprioception markers after maximal eccentric exercise of the elbow flexors (EF: Study 1) and the knee flexors (KF: Study 2) in comparison to a sham treatment condition. In each study, 24 healthy sedentary women were assigned t...

Introduction: The present study tested the hypothesis that eccentric training (ET) of non-immobilized arm would attenuate negative effects of immobilization and provide greater protective effects against muscle damage induced by eccentric exercise after immobilization, when compared with concentric training (CT). Methods: Sedentary young men wer...

Connected adaptive resistance exercise (CARE) machines are new technology purported to adjust resistance exercise loads in response to muscle fatigue. The present study examined muscle fatigue (strength loss, fatigue perceptions) during maximal eccentric-only (ECCmax -only), concentric-only (CONmax -only), and coupled ECC-CON (ECCmax -CONmax ) bice...

The aim of this study was to examine the validity and reliability of an Inertial Measurement System integrated into a secondary pulley (IMS) for determining linear velocity during flywheel squat exercises. Thirty-one male participants who were highly experienced in a flywheel resistance exercise training performed flywheel squat exercises with thre...

Purpose To understand muscle damage in badminton, changes in neuromuscular function were investigated after simulated badminton singles matches performed by ten state-level male players. Methods Each participant played eight matches and measurements were taken before, immediately after, and 1 and 24 h after each match. Maximal voluntary isometric...

Wing, C, Hart, NH, Ma'ayah, F, and Nosaka, K. Replicating maximum periods of play in Australian football matches through position-specific drills. J Strength Cond Res XX(X): 000-000, 2022-This study evaluated whether a position-specific drill replicates the running intensities of maximum ball in play (BiP) phases in competitive matches of Australia...

Shibata, K, Yamaguchi, T, Takizawa, K, and Nosaka, K. Comparison in repetitions to failure between concentric-only and eccentric-only dumbbell arm curl exercise at four different relative intensities. J Strength Cond Res XX(X): 000-000, 2022-The repetitions to failure (RF) were compared between concentric-only (CON) and eccentric-only (ECC) arm cur...

Cross-education is the phenomenon where training of one limb can cause neuromuscular adaptations in the opposite untrained limb. This effect has been reported to be greater after eccentric (ECC) than concentric (CON) strength training; however, the underpinning neurophysiological mechanisms remain unclear. Thus, we compared responses to transcrania...

The present study investigated the effects of a 3‐week immobilization (IM) on muscle damage induced by maximal eccentric exercise (MaxEC) to test the hypothesis that the IM would make muscles prone to muscle damage. Young healthy sedentary men were pseudo‐randomly assigned to IM or control group (n=12/group). Non‐dominant arms of the IM group parti...

Background The extramuscular connective tissue (ECT) has been shown to play a significant role in mechanical force transmission between musculoskeletal structures. Due to this and owing to its tight connection with the underlying muscle, the ECT may be vulnerable to excessive loading. The present study aimed to investigate the effect of eccentric e...

Cuong Le, C, Ma'ayah, F, Nosaka, K, Hiscock, D, and Latella, C. Effects of high-intensity position-specific drills on physical and technical skill performance in elite youth soccer players. J Strength Cond Res XX(X): 000-000, 2022-Soccer physical preparation has been extensively researched with previous emphasis on high-intensity interval running a...

The actual capacity to perform tasks, and actual fatigue, are concepts that have been thought of as inherently linked. These considerations also extend to their phenomenology, meaning the perception(s) of capacity or fatigue. The phenomenology of capacity or fatigue thus may be capturing the same underlying latent construct. Further, it is speculat...

Skeletal muscle extracellular matrix (ECM) is critical for muscle force production and the regulation of important physiological processes during growth, regeneration, and remodelling. ECM remodelling is a tightly orchestrated process, sensitive to multi-directional tensile and compressive stresses and damaging stimuli, and its assessment can conve...

This study investigated the impact of the 2020 COVID-19 lockdown on community-dwelling older adults attending a community-based exercise program to seek strategies to keep them active during self-isolated situations. A two-phase mixed methods approach included a survey followed by in-person focus groups. Forty-eight participants, with 32 starting a...

Purpose Ultrasound-derived echo intensity (EI) has been used as a physiological marker for changes in skeletal muscle ‘quality’ with physical training, disuse, ageing, and neuromuscular disorders. However, the methodological and physiological factors influencing EI and its longitudinal change are still unclear. Here, we performed two separate expe...

This study evaluated the physical demands and specificity of small-sided games (SSGs) compared to matches in Australian Football (AF). Global positioning system (GPS) data was collected on 48 AF players from 39 matches and 28 training sessions across two seasons. Match data was analysed using the ball in play (BiP) method with the maximum BiP perio...

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...

Eurycoma longifolia Jack (ELJ) is a herbal plant that has androgenic and antioxidant effects. We investigated the short-term effect of ELJ supplementation on muscle damage induced by eccentric exercise. Eighteen young (19–25 years), well-trained rugby 7s players were assigned to an ELJ or a placebo (PLA) group (n = 9/group). Each participant took f...

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...

This study investigated the effects of reduced quarter time due to COVID-19 pandemic rule changes, on running performance and injuries in Australian Football. Microsensor data for eight matches performed by the same 17 players were compared between the 2019 (standard) and 2020 (COVID-19) seasons using linear and generalised mixed models. Injury rat...

Tensiomyography is a non-invasive method to assess skeletal muscle contractile properties from the stimulated radial displacement. Many studies have used the rate of displacement (Vc) as an indirect measure of muscle contraction velocity. However, no standardised methodical approach exists to measure displacement and determine Vc. This review aimed...

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...

Our previous study found that one maximal voluntary eccentric contraction (MVC‐ECC) performed daily for five days a week for four weeks increased MVC‐ECC, isometric (MVC‐ISO), and concentric contraction (MVC‐CON) torque of the elbow flexors more than 10%. The present study investigated the effects of six maximal voluntary eccentric contractions on...

Purpose The aim of this review was to (1) characterize the time-course of markers of exercise-induced muscle damage (EIMD) based on the level of maximal voluntary contraction torque loss at 24-48h post-exercise (MVCloss24-48h), (2) identify factors (e.g., exercise and population characteristics) affecting the level of MVCloss24-48h, and (3) evaluat...

Purpose: The authors investigated whether far-infrared radiation (FIR) lamp therapy would reduce muscle damage and enhance recovery from multiple soccer-match-related running activities. Methods: Twenty-four elite female soccer players (20-24 y) were assigned into a FIR or a sham treatment group (n = 12/group). They performed a daily 90-minute L...

An acute bout of eccentric exercise affects insulin sensitivity and lipid profile, but how the magnitude of muscle damage affects them is not clear. We compared changes in blood insulin sensitivity and lipid markers after the first (EC1) and second (EC2) eccentric exercise bouts. Fifteen sedentary young men performed arm, leg and trunk muscle eccen...

Changes in biceps brachii muscle hardness assessed by a push-in meter (PM) and strain elastography (SE) were compared between eccentric (ECC) and concentric contractions (CON) of the elbow flexors to test the hypothesis that muscle hardness would increase greater after ECC. Ten men performed 5 sets of 10 ECC with their non-dominant arms and 5 sets...

This study examined the number of smashes and smash-lunge sequences in elite men’s singles matches. Semi-final and final match videos of the Olympic Games, Grand-Prix, and World-SuperSeries in 2016 were analysed. Points won from smashes and smash-lunge sequence in a game and an entire match were compared between the winners and losers, and whether...

Background Poorer sleep health outcomes have been documented in the general population during the COVID-19 outbreak. However, the impact of the COVID-19 outbreak on sleep health outcomes in specific population groups, including the sporting community, has not been extensively investigated. This study evaluated sleep health outcomes and their relati...

Effects of eccentric (ECC) versus concentric (CON) strength training of the upper body performed twice a week for 10 weeks followed by detraining for five weeks on maximal force, muscle activation, muscle mass and serum hormone concentrations were investigated in young women (n = 11 and n = 12). One-repetition bench press (1RM), maximal isometric f...

Mixed martial arts (MMA) is a combat sport encompassing multiple methods of victory, including knockout, submission, and decision. Although research exists investigating physical and physiological characteristics important to MMA success, there is no consensus on the characteristics essential to performance and best practice for the assessment of s...

Purpose: Explosive performance is increased right after performing loaded resistance exercise, which is known as post-activation performance enhancement (PAPE). Method: We investigated the effects of a plyometric exercise (PLYO) consisting of five sets of six drop-jumps from a 52-cm platform with a load corresponding to 20% body mass on changes in...

Background This study compared the physical demands and effect of field location for different phases of play (offence, defence and contested), and examined the physical and technical demands of successful and unsuccessful phases of play during Australian Football matches. Methods Global positioning system (GPS) and technical performance data were...

Nordic hamstring exercise is performed to prevent knee flexor muscle strain injuries and used to assess their injury risks. However, what exactly Nordic hamstring strength indicates is not clear. We investigated the relationship between Nordic hamstring strength and maximal voluntary contraction (MVC) torque of the knee flexors measured by an isoki...

The present study compared a 3‐second isometric maximal voluntary contraction (MVC), concentric MVC and eccentric MVC of the elbow flexors performed daily for 5 days a week for 4 weeks for changes in muscle strength and thickness. Young sedentary individuals were assigned to one of three training groups (n=13 per group) that performed either 3‐seco...

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...

PurposeThe present study compared the effects of eccentric cycling (ECC) and conventional concentric cycling (CONC) training on muscle function, body composition, functional performance, and quality of life (QOL) of patients with moderate chronic obstructive pulmonary disease (COPD).Methods Twenty patients (age: 69.6 ± 10.1 years, forced expiratory...

Abstract Background This study compares ball in play (BiP) analyses and both whole game (WG) and quarter averaged data for physical and technical demands of sub-elite Australian football (AF) players competing in the West Australian Football League across playing positions. Methods Microsensor data were collected from 33 male AF players in one club...

The present study compared the first (EC1) and second (EC2) bouts of whole-body eccentric exercises to examine the effects of the magnitude of muscle damage on changes in blood bone markers. Fifteen sedentary young men performed nine eccentric exercises of arm, leg and trunk muscles, and repeated them two weeks later. Blood samples were taken befor...

Kotani, Y, Lake, J, Guppy, SN, Poon, W, Nosaka, K, Hori, N, and Haff, GG. The reliability of the squat jump force-velocity and load-velocity profiles. J Strength Cond Res XX(X): 000-000, 2021-The purpose of this study was to investigate the between-session reliability of the squat jump force-velocity (FV) and load-velocity (LV) profiles. Eighteen s...

PurposeThe present study compared isometric, concentric and eccentric contractions at the same torque-time integral for changes in neuromuscular fatigue and muscle damage parameters.Method Healthy men (18–24 years) were placed to either isometric (ISO), concentric (CONC), or eccentric (ECC) group (n = 11/group) that performed corresponding contract...

Background The benefits of resistance training for patients with type 2 diabetes (T2D) are well documented; however, the effects of exercise with different muscle contraction types such as eccentric versus concentric contractions on physiological outcomes for this population are not clear. This study compared eccentric-only (ECC) and concentric-onl...

Background Australian Football is a fast paced, intermittent sport, played by both male and female populations. The aim of this systematic review was to compare male and female Australian Football players, competing at elite and sub-elite levels, for running performance during Australian Football matches based on the Preferred Reporting Items for S...

Purpose We investigated the effects of three different unilateral isoinertial resistance training protocols with eccentric-overload on changes in lean mass and muscle function of trained (TL) and contralateral non-trained (NTL) legs. Methods Physically-active university students were randomly assigned to one of three training groups or a control g...