Saied Jalal Aboodarda

The University of Calgary | HBI · Faculty of Kinesiology

The present study investigated the effects of exercise-induced elbow flexor fatigue on voluntary force output, EMG activity and motoneurone excitability of the non-exercised knee extensor muscles. Eleven participants attended three testing sessions: i) control, ii) fatiguing unilateral elbow flexion (UniFlex) and iii) fatiguing bilateral elbow flex...

Exercise-induced fatigue can change motor performance in non-exercised muscles. The objective was to investigate unilateral elbow flexion (EF) fatigue effects on the maximal voluntary force (MVC) and corticospinal excitability of contralateral non-exercised biceps brachii (BB). Transcranial magnetic, transmastoid electrical and brachial plexus e...

Key points: Fatigue and muscle pain induced in a remote muscle group has been shown to alter neuromuscular performance in exercising muscles. Inhibitory neural feedback associated with activation of mechano- and metabo-sensitive muscle afferents has been implicated in this phenomenon. This study aimed to quantify and compare the effects of pre-ind...

Experiencing pain in one leg can alter exercise tolerance and neuromuscular fatigue (NMF) responses in the contralateral leg; however, the corticospinal modulations to nonlocal experimental pain induced by blood flow occlusion remain unknown. In three randomized visits, 13 male participants performed 25% of isometric maximal voluntary contraction (...

A comprehensive characterization of neuromuscular and perceptual mechanisms of fatigue at task failure following exercise across the entire intensity spectrum is lacking. This study evaluated the extent of peripheral and central fatigue, and corresponding perceptual attributes, at task failure following cycling within the moderate-(MOD), heavy-(HVY...

This study assessed the validity of the Entralpi force plate in the assessment of finger flexor performance in rock climbers. In addition to a static force evaluation, peak force, peak impulse, and total impulse were measured during 30 all-out performance trials by 15 participants, in which force during the trials was recorded simultaneously by the...

MacDougall, KB, McClean, ZJ, MacIntosh, BR, Fletcher, JR, and Aboodarda, SJ. Ischemic preconditioning, but not priming exercise, improves exercise performance in trained rock climbers. J Strength Cond Res XX(X): 000-000, 2023-To assess the effects of ischemic preconditioning (IPC) and priming exercise on exercise tolerance and performance fatigabil...

The purpose of this study was to assess the test-retest reliability of a 4-minute all-out critical force test in well-trained rock climbers. Thirteen rock climbers (n=4 females) completed a familiarization session and two all-out critical force tests on different days. During each trial, participants completed 24 repetitions of 7s right-handed, max...

Muscle pain is an important determinant of exercise tolerance, but its relationship with neurophysiological responses during a submaximal exercise trial is unclear. The purpose of this study was to determine the effect of persistent contralateral pain on neurophysiological function and perceptual responses during, ipsilateral isometric knee extensi...

Purpose Constant blood flow occlusion (BFO) superimposed on aerobic exercise can impair muscle function and exercise tolerance; however, no study has investigated the effect of intermittent BFO on the associated responses. Fourteen participants (n = 7 females) were recruited to compare neuromuscular, perceptual, and cardiorespiratory responses to s...

This study aimed to characterize neuromuscular, perceptual, and cardiorespiratory responses to high-intensity interval training (HIIT) with superimposed blood flow restriction in males and females. Twenty-four, healthy individuals (n=12 females) completed two cycling HIIT protocols to task failure (1-min work phases at 90% of peak power output inte...

Introduction: The intensity, duration, and distribution of work and recovery phases during high intensity interval training (HIIT) modulate metabolic perturbations during exercise, and subsequently influence the development of performance fatigability and exercise tolerance. This study aimed to characterize neuromuscular, perceptual, and cardiores...

While neuromuscular fatigability has been previously characterized after running and cycling, no study has investigated an ultra-endurance upper body task. In preparation for a world record attempt, three pacing strategies to perform 1980 pull-ups in 6 hrs were compared during independent sessions: fast pace, long recovery (FL), fast pace, multiple...

Whereas fatigue is recognized to be the main complaint of patients with multiple sclerosis (PwMS), its etiology, and particularly the role of resistance to fatigability and its interplay with disability level, remains unclear. The purposes of this review were to (i) clarify the relationship between fatigue/disability and neuromuscular performan...

Hypoxia negatively impacts aerobic exercise, but exercise testing in hypoxia has not been studied comprehensively. To determine the effects of simulated altitude on the gas exchange threshold (GET), respiratory compensation point (RCP), and maximal oxygen uptake (V̇O2max), 24 participants (mean [SD]; 26 [4] years; 171.6 [9.7] cm; 69.2 [11.9] kg) ac...

Purpose: to investigate the time course and amplitude of performance fatigability during cycling at intensities around the maximal lactate steady state (MLSS) until task failure (TTF). Methods: 10 females and 11 males were evaluated in 8 visits: 1) ramp incremental test; 2-3) 30-min constant power output (PO) cycling for MLSS determination; 4-8)...

Neuromuscular (NM) fatigue can vary according to exercise intensity and duration; however, fatigue responses across the full spectrum of exercise intensities to task failure remain unclear. PURPOSE: To characterize the central and peripheral NM fatigue responses to cycling to task failure in different exercise intensity domains. METHODS: After a ra...

Neuromuscular (NM), cardiorespiratory, and perceptual responses to maximal graded exercise using different amounts of active muscle mass remain unclear. We hypothesized that during dynamic exercise, peripheral NM fatigue (declined twitch force) and muscle pain would be greater using smaller muscle mass, whereas central fatigue (declined voluntary a...

Non-local muscle fatigue (NLMF) studies have examined cross-over impairments of maximal voluntary force output in non-exercised , contralateral muscles as well as comparing upper and lower limb muscles. Since prior studies primarily investigated contrala-teral muscles, the purpose of this study was to compare NLMF effects on elbow flexors (EF) and...

It is unclear whether motor fatigability and perceived fatigue share a common pathophysiology in people with multiple sclerosis (PwMS). This cross-sectional investigation explored the relationship between the mechanisms of motor fatigability from cycling and fatigue severity in PwMS. Thirteen highly fatigued (HF) and thirteen non-fatigued (LF) PwMS...

Although it has been claimed that rolling massage (RM), may lead to improvements in skeletal muscle oxygenation, metabolism, blood flow, and vascular function, scientific evidence has not yet been provided. Thus, the current study investigated the effects of 30 s and 2 min of RM on forearm muscle oxygenation, and parameters associated with oxidativ...

To investigate the effects of one leg exercise-induced fatigue and pain on the contralateral leg exercise tolerance, NM and perceptual responses. METHODS: Nine healthy young men (age: 26±7 years) performed right leg sustained contraction at 25% of isometric maximal voluntary contraction (25%IMVC) to task failure. In three testing sessions, the 25%I...

Studies have suggested that older individuals are more fatigable than young adults when power loss, measured during single-joint contractions, is considered the fatigue index; however, age-related differences in fatigue considering power measurements during multi-joint movements (e.g., cycling) have not been fully elucidated yet. This study examine...

To investigate the influence of pre-induced fatigue in one leg on neuromuscular performance and corticospinal responses of the contralateral homologous muscles, three experiments were conducted with different exercise protocols; A (n = 12): a 60 s rest vs. time-matched sustained left leg knee extension maximum voluntary contraction (MVC), B (n = 12...

The majority of studies have routinely measured neuromuscular (NM) fatigue with a delay (~1–3 min) after cycling exercises. This is problematic since NM fatigue can massively recover within the first 1-2 minutes after exercise. This study investigated the etiology of knee extensors (KE) NM fatigue and recovery kinetics in response to cycling exerci...

While fatigue can be defined as an exercise-related decrease in the maximal power or isometric force, most studies have assessed only isometric force. The main purpose of this experiment was to compare dynamic measures of fatigue [maximal torque (Tmax), maximal velocity (Vmax) and maximal power (Pmax)] with measures associated with maximal isometri...

Background: The recovery of neurophysiological parameters at various time intervals following fatiguing exercise has been investigated previously. However, the repetition of neuromuscular assessments during the recovery period may have interfered with the true corticomotor excitability responses. In this experiment, fatiguing contractions were com...

Purpose The adaptations induced by endurance training on the neuromuscular function remain under investigation and, for methodological reasons, unclear. This study investigates the effects of cycling training on neuromuscular fatigue and its peripheral contribution measured during and immediately after cycling exercise. Methods Fourteen healthy me...

This study investigated the effects of 9-week endurance cycling training on central fatigability and corticomotor excitability of the locomotor muscles. Fourteen healthy participants undertook three incremental fatiguing cycling tests to volitional exhaustion (EXH): (i) before training (PRE), (ii) after training at the same absolute power output as...

Purpose: The assessment of power changes after fatiguing exercise provides important additional information about neuromuscular function compared to traditional isometric measurements, especially when exploring age-related changes in fatigability. Therefore, the aim of this review was to explore the effects of age on neuromuscular fatigue (NMF) wh...

Fatigue is the most common and often most disabling symptom experienced by people with MS, yet its etiology remains unclear. It is possible that some of the mechanisms of MS-related fatigue could concurrently affect neuromuscular function (ie. the processes involved in muscle contraction, from the motor cortex of the brain to the skeletal muscle),...

The aim of the present study was to investigate the alterations of corticospinal excitability (motor evoked potential, MEP) and inhibition (silent period, SP) following rolling massage of the quadriceps muscles. Transcranial magnetic and femoral nerve electrical stimuli were used to elicit MEPs and compound muscle action potential (Mmax) in the vas...

In this study, neuromuscular fatigue recovery was investigated in elbow flexors using transcranial magnetic stimulation (TMS) of the cerebral cortex in combination with transmastoid (TMES) and brachial plexus electrical stimulation (BPES).

The term fatigue is used to describe a distressing and persistent symptom of physical and/or mental tiredness in certain clinical populations, with distinct but ultimately complex, multifactorial and heterogenous pathophysiology. Chronic fatigue impacts on quality of life, reduces the capacity to perform activities of daily living, and is typically...

PURPOSE: The purpose of the present study was to examine the effects of unilateral fatigue of the knee extensors at different movement velocities on neuromuscular performance in the fatigued and non-fatigued leg. METHODS: Unilateral fatigue of the knee extensors was induced in 11 healthy young men (23.7 ± 3.8 years) at slower (60°/s; FAT60) and fas...

Introduction: Roller massage (RM) has been reported to reduce pain associated with exercise-induced muscle soreness and increase range of motion without force or activation impairments. The objective was to examine RM effects on evoked pain and contractile properties. Methods: Twelve men received three sets of 30-s RM at a perceived discomfort l...

Equivocal evidence indicates that high intensity muscle contractions can affect the corticospinal responses in muscles not directly involved in the task. In the present study, the responsiveness of corticomotor pathway innervating non-dominant biceps brachii was measured in eleven healthy participants before and after: i) two 100-s isometric unilat...

The objective of this study was to develop a standardized test to determine quadriceps and hamstrings muscle activation in a position emulating a non-contact anterior cruciate ligament injury. We assessed the intra- and inter-session reliability of surface electromyography (EMG) of the dominant leg following single-leg landing from a standardized h...

Foam rolling has been shown to increase range of motion without subsequent performance impairments of the rolled muscle, however, there are no studies examining rolling effects on antagonist muscles. The objective of this study was to determine whether foam rolling the hamstrings and/or quadriceps would affect hamstrings and quadriceps activation i...

Background: Elastic resistance has been commonly used in the therapeutic and fitness setting; however, the ability of elastic resistance to overload and activate muscles has been questioned because of linear increase in elastic resistance as the device is elongated. The purpose of this meta-analysis was to examine the available literature on muscl...

Exercise-induced fatigue affects muscle performance and modulates corticospinal excitability in non-exercised muscles. The purpose of this study was to investigate the effect of bilateral knee extensor fatigue on dominant elbow flexor (EF) maximal voluntary force production and corticospinal excitability. Transcranial magnetic, transmastoid electri...

Introduction: The initial rapid eccentric contraction of a stretch-shortening cycle (SSC) activity is typically reported to accentuate the subsequent concentric jump performance. Some researchers have rationalized that adding elastic resistance (ER) to explosive type activities (e.g. countermovement jumps and drop jumps) would increase excitatory s...

The purpose of the current study was to assess the effects of 5 brief (2s), intermittent, submaximal elbow flexors voluntary contractions at 50% of maximal voluntary contraction (MVC) on measures of central (i.e. supraspinal and spinal) excitability. Supraspinal and spinal excitability of the biceps brachii were assessed via transcranial magnetic s...

Background The aim of the present study was to determine the acute effect of rolling massage on pressure pain threshold (PPT) in individuals with tender spots in their plantar flexor muscles. Methods In a randomized control trial and single blinded study, tender spots were identified in 150 participants’ plantar flexor muscles (gastrocnemius or s...

The aim of this study was to examine the effects of an ankle compression garment (CG) on muscle performance and physiological variables associated with recovery from fatigue. Fifteen participants took part in a randomized, crossover study design with two experimental conditions (ankle CG and control). The dependent variables: skin temperature, evok...

Background: The aim of the present study was to determine the acute effect of rolling massage on pressure pain threshold (PPT) in individuals with tender spots in their plantar flexor muscles. Methods: In a randomized control trial and single blinded study, tender spots were identified in 150 participants’ plantar flexor muscles (gastrocnemius or s...

The purpose of this study was to investigate different intensities of unilateral fatiguing dynamic quadriceps contractions on non-exercised, contralateral quadriceps performance. In a randomized crossover study design with 12 recreationally trained male (1.78 ± 0.05 m, 84.5 ± 7.6 kg, 30.0 ± 8.5 yrs) participants, maximal voluntary contraction (MVC)...

Most studies have examined pacing strategies with cycli-cal activities (running and cycling). It has been demon-strated that males employ different pacing strategies dur-ing repeated maximal voluntary contractions (MVCs) dependent upon a known endpoint. Since different fatigu-ing mechanisms have been identified between the gen-ders, it is not known...

Aboodarda, SJ, Byrne, JM, Samson, M, Wilson, BD, Mokhtar, AH, and Behm, DG. Does performing drop jumps with additional eccentric loading improve jump performance? J Strength Cond Res 28(8): 2314-2323, 2014-Previous investigators have speculated that applying additional external load throughout the eccentric phase of the jumping movement could ampli...

Previous investigators have speculated that applying additional external load throughout the eccentric phase of the jumping movement could amplify the stretch shortening cycle mechanism and modulate jumping performance and jump exercise intensity. The aims of the present study therefore were to determine the effect of increased eccentric phase load...

Abstract Non-local muscle fatigue has been demonstrated with unilateral activities, where fatiguing one limb alters opposite limb forces. Fewer studies have examined if non-local fatigue occurs with unrelated muscles. The purpose of this study was to investigate if knee extensors fatigue alters elbow flexors force and electromyography (EMG) activit...

Pacing strategies have been reported to occur during continuous cyclical exercises. However, currently no studies have examined if pacing takes place during repeated maximal voluntary muscle contractions (MVCs). Accordingly, the purpose of this study was to examine if informing subjects on the number of MVCs they would perform would affect force an...

Limited dorsiflexion range of motion (ROM) has been linked to lower limb injuries. Improving limited ankle ROM may decrease injury rates. Static stretching (SS) is ubiquitously used to improve ROM but can lead to decreases in force and power if performed prior to the activity. Thus, alternatives to improve ROM without performance decrements are nee...

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Purpose: To identify the effect of additional elastic force on the kinetic and kinematic characteristics, as well as the magnitude of leg stiffness, during the performance of accentuated countermovement jumps (CMJs). Methods: Fifteen trained male subjects performed 3 types of CMJ including free CMJ (FCMJ; ie, body weight), ACMJ-20, and ACMJ-30 (...

Variable resistance training (VRT) such as that employed by equipment that utilizes asymmetrical cams or pulleys (ASYM CAM) (e.g., Nautilus Machines) and elastic resistance (ELASTIC) are commonly used by athletes and fitness enthusiasts. However, the use of ELASTIC in high intensity training protocols has been controversial due to the limitation of...

The purpose of the present study was to identify the effect of additional elastic force on the kinetic and kinematic characteristics as well as the magnitude of leg stiffness during the performance of accentuated CMJs. Fifteen trained male subjects performed three types of CMJ including FCMJ (i.e. body weight), ACMJ-20 and ACMJ-30 (i.e. accentuated...

Electromyographic Activity and Applied Load During High Intensity Elastic Resistance and Nautilus Machine Exercises This study was designed to quantify and compare Electromyographic activity (EMG) and applied load in quadriceps muscle within performing high intensity knee extension exercises by Elastic Resistance (ER) and Nautilus Machine (NM). Six...

Nautilus Machine (NM) and Elastic Resistance (ER) have gained considerable popularity among athletes and recreational lifters seeking to increase muscle strength. However, there is controversy concerning the use of ER for increasing muscle hypertrophy and strength among healthy-trained individuals. The aim of the study was to compare the effect of...

The purpose of this study was to quantify and compare Resultant Muscle Torque (RMT) and muscle activation (EMG) pattern, during resistance exercise comprising eight repetitions maximum (8 RM) biceps curl with elastic resistance and free weight exercise. Sixteen male and female recreationally active subjects completed 8 RM biceps curl by each of thr...

This investigation was conducted to quantify and compare Resultant Muscle Torque (RMT) pattern in quadriceps muscle using elastic resistance training device. Sixteen subjects completed 8-RM seated knee extension by elastic tubing with original length (E0) and elastic tubing with 30% decrement of original length (E30). Every repetition was partition...

The purpose of this study, therefore, was to quantify and compare Integrated Electromyography (I-EMG) within perfuming 8-RM seated knee extension in contribution of elastic resistance and nautilus machine exercises. All data were collected within one testing session. Subjects completed 8-RM seated knee extension by three modalities of resistance ex...