Kevin Thomas

• PhD
• Lecturer at Northumbria University

Synaptic input to the motoneuron pool is altered during fatiguing muscle contractions. In humans, the corticospinal tract is often studied, with equivocal findings regarding its role in the reduction of force. To date, the involvement of the reticulospinal tract during states of fatigue has not been explored. Fourteen participants (28[6] years, nin...

Experimental studies showed improvement in physical performance following acute application of transcranial direct current stimulation (tDCS). This study examined the neuromuscular and neural response to a single training session (Part 1) and after a 3-week resistance training (Part 2) performed with the knee extensors, preceded by tDCS over the pr...

Unaccustomed eccentric exercise (EE) is protective against muscle damage following a subsequent bout of similar exercise. One hypothesis suggests the existence of an alteration in motor unit (MU) behaviour during the second bout, which might contribute to the adaptive response. Accordingly, the present study investigated MU changes during repeated...

Soccer match play and training have been documented to significantly impair players' physical function and affect their perceptual wellness, indicating the necessity of evaluating the response to mixed-content training across a soccer season (Deely et al., 2022, Front Physiol, 13, 911009; Brownstein et al., 2017, Front Physiol, 8, 831; Thomas et al...

Contraction intensity is a key factor determining the development of muscle fatigue and it has been shown to induce distinct changes along the motor pathway. The role of cortical and spinal inputs that regulate motor unit (MU) behaviour during fatiguing contractions is poorly understood. We studied the cortical, spinal, and neuromuscular response t...

This study examined the type, frequency, and severity of symptoms experienced by naturally menstruating women and combined, monophasic, oral contraceptive pill users and their perceived effects on exercise performance and recovery time posttraining. Forty-two recreationally active women; 21 naturally menstruating and 21 combined, monophasic, oral c...

This study investigated the validity and reliability of measuring patellar tendon (PT) cross-sectional area (CSA) using magnetic resonance imaging (MRI) and ultrasound (US) imaging. Nineteen healthy participants (10 women, 9 men) participated in three imaging sessions of the PT, once via MRI and twice via US, with image acquisition conducted by two...

Resistance training increases volitional force producing capacity, and it is widely accepted that such an increase is partly underpinned by adaptations in the central nervous system, particularly in the early phases of training. Despite this, the neural substrate(s) responsible for mediating adaptation remains largely unknown. Most studies have foc...

Elite youth soccer training elicits substantial decrements in neuromuscular function, which are still present 72 h post-strenuous exercise • It is the restitution of muscular function (peripheral mechanisms) that predominantly explains recovery from strenuous training in academy soccer players • It is prudent to use both objective and subjective me...

Aim: To profile the etiology and recovery time-course of neuromuscular function in response to a mixed-content, standard training week in professional academy soccer players. We concurrently examined physical performance, cognitive function, and perceptual measures of mood and wellness states to identify a range of simple tests applied practitioner...

Purpose: To assess the association between the W' and measures of neuromuscular function relating to the capacity of skeletal muscle to produce force in a group of elite cyclists. Methods: Twenty-two athletes specializing in a range of disciplines and competing internationally volunteered to participate. Athletes completed assessments of maximum...

Our aim was to determine the demands and consequences of a single session of continuous (CONT) or interval (INT) eccentric cycling. Fourteen healthy males performed ‘work-matched’ CONT and INT eccentric cycling in a cross over design. Measures of maximal voluntary contraction (MVC), resting twitch force, voluntary activation (VA), muscle soreness,...

New findings: What is the topic of this review? We review sex differences within physiological systems implicated in exercise performance; specifically, how they integrate to determine metabolic thresholds and fatigability. Thereafter, we discuss the implications that these sex differences might have for long-term adaptation to exercise. What adva...

Background Concentrations of endogenous sex hormones fluctuate across the menstrual cycle (MC), which could have implications for exercise performance in women. At present, data are conflicting, with no consensus on whether exercise performance is affected by MC phase.Objective To determine the effects of the MC on exercise performance and provide...

Background Oral contraceptive pills (OCPs) are double agents, which downregulate endogenous concentrations of oestradiol and progesterone whilst simultaneously providing daily supplementation of exogenous oestrogen and progestin during the OCP-taking days. This altered hormonal milieu differs significantly from that of eumenorrheic women and might...

Key points Knee‐extensors demonstrate greater fatigue resistance in females compared to males during single‐limb and whole‐body exercise. For single‐limb exercise, the intensity–duration relationship is different between sexes, with females sustaining a greater relative intensity of exercise. This study established the power–duration relationship d...

This study assessed the efficacy of strength training using augmented eccentric loading to provoke increases in leg strength in well-trained athletes, and sprint track cyclists, using a novel leg press device. Twelve well-trained athletes were randomly allocated traditional resistance training (TRAD, n = 6), or resistance training using augmented e...

Over the last two decades, an abundance of research has explored the impact of fatiguing locomotor exercise on the neuromuscular system. Neurostimulation techniques have been implemented prior to and following locomotor exercise tasks of a wide variety of intensities, durations, and modes. These techniques have allowed for the assessment of alterat...

Introduction This study aimed to assess the efficacy of a six‐week cycling‐specific, isometric resistance training programme on peak power output (PPO) in elite cyclists. Methods Twenty‐four elite track sprint cyclists were allocated to EXP (n=13, PPO, 1537 ± 307 W) and CON (n=11, PPO, 1541 ± 389 W) groups. All participants completed a six‐week tr...

New findings: What is the central question of the study? Neural adaptations to resistance training are known to be task-specific, however adaptation to resistance training using compound movements are typically assessed in a single-limb isometric task. This study aimed to assess whether corticospinal responses to acute and short-term squat resista...

Key points Females demonstrate greater fatigue resistance than males during contractions at intensities relative to maximum force. However, previous studies have not accounted for the influence of metabolic thresholds on fatigability. This study is the first to test whether sex differences in fatigability exist when exercise intensity is normalised...

Aim: Cryotherapy is commonly implemented following soccer match-play in an attempt to accelerate the natural time-course of recovery, but the effect of this intervention on neuromuscular function is unknown. The aim of the present study was to examine the effect of donning lower-body garments fitted with cooled phase change material (PCM) on recove...

Sex hormone concentrations of eumenorrheic females typically fluctuate across the menstrual cycle and can affect neural function such that oestrogen has neuro-excitatory effects, and progesterone induces inhibition. However, the effects of these changes on corticospinal and intracortical circuitry, and the motor performance of the knee-extensors, a...

Electrical stimulation over the mastoids or thoracic spinous processes has been used to assess subcortical contribution to corticospinal excitability, but responses are difficult to evoke in the resting lower limbs or are limited to only a few muscle groups. This might be mitigated by delivering the stimuli lower on the spinal column, where the des...

Cross-education describes the strength gain in the opposite, untrained limb following a unilateral strength training program. Since its discovery in 1894, several studies now confirm the existence of cross-education in contexts that involve voluntary dynamic contractions, eccentric contraction, electrical stimulation, whole-body vibration and, more...

The study aimed to determine the optimal application of single- and paired-pulse transcranial magnetic stimulation (TMS) in the rectus femoris. Twenty-nine male adults participated in the study, which involved 5 separate experiments. Experiments 1 to 3 assessed the effect of conditioning stimulus (CS) intensity (60, 70, 80 and 90% active motor thre...

The critical threshold hypothesis proposes that performance fatigability during high-intensity exercise is tightly regulated by negative-feedback signals from the active muscles. We propose that performance fatigability is simply dependent on the exercise mode and intensity; the consequent adjustments, in skeletal muscle and the other physiological...

Purpose: Training methods that require maximal intensity efforts against light- and heavy-resistance are commonly used for athletic development. Typically these sessions are separated by at least 48 hours recovery on the assumption that such efforts elicit marked fatigue of the central nervous system (CNS), but this posit has not been well-studied...

New findings: What is the central question of this study? In order to discern information about testing modalities when assessing neuroplastic responses to squat resistance training, the present study investigated whether corticospinal and intracortical function was different between a joint-angle matched isometric squat, and isometric knee extens...

Reduced maximal force capability of skeletal muscle, as a consequence of exercise, can be due to peripheral or central fatigue mechanisms. In upper-limb muscles, neuromuscular fatigue is concurrent with reduced corticospinal excitability and increased inhibition (lengthened corticospinal silent period [CSP]; reduced short-interval intracortical inh...

Females are less fatigable than males during isometric contractions across various muscles and intensities. However, sex differences in knee-extensor fatigability remain relatively unexplored Purpose To determine the sex difference in performance fatigability for intermittent, isometric contractions of the knee-extensor muscles. Methods Eighteen...

Purpose: To investigate the effects of feedback, in the form of a virtual avatar paced at 100 and 102% of baseline performance, on neuromuscular fatigue following a 4 km cycling time trial (TT). We hypothesised that improved cycling performance would occur due to participants exceeding a previously established critical threshold, and experiencing g...

Aim: Previous research into the etiology of neuromuscular fatigue following competitive soccer match-play has primarily focused on peripheral perturbations, with limited research assessing central nervous system function in the days post-match. The aim of the present study was to examine the contribution and time-course of recovery of central and p...

PurposeThis investigation examined the development of neuromuscular fatigue during a simulated soccer match incorporating a period of extra time (ET) and the reliability of these responses on repeated test occasions. Methods Ten male amateur football players completed a 120 min soccer match simulation (SMS). Before, at half time (HT), full time (FT...

Purpose The aim of the present study was to investigate whether a magnitude of deception of 5% in power output would lead to a greater reduction in the amount of time taken for participants to complete a 4000 m cycling TT than a magnitude of deception of 2% in power output, which we have previously shown can lead to a small change in 4000 m cycling...

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Purpose: We profiled the etiology and recovery of neuromuscular fatigue post-simulated-soccer-match-play. Methods: Fifteen semi-professional players completed a 90 min simulated soccer match. Pre-, immediately-post and at 24, 48 and 72 h participants completed a battery of neuromuscular, physical and perceptual tests. Perceived fatigue and muscl...

Aim: To determine if neuromuscular disturbances are modulated following a repeated bout of eccentric exercise METHODS: Following eccentric exercise performed with the elbow-flexors, we measured maximal voluntary force, resting twitch force, muscle soreness, creatine kinase and voluntary activation using motor point and motor cortex stimulation at...

The physiological and performance responses to 90 min of soccer-specific exercise are well known. However, the responses to 120 min of soccer-specific exercise (i.e., inclusion of an extra-time period; ET) are unclear. This is despite the importance of ET in determining match outcomes in tournament match-play. PURPOSE: To profile the performance a...

Purpose: We tested the hypothesis that central and peripheral fatigue after constant-load cycling exercise would vary with exercise intensity and duration. Methods: Twelve, well-trained male cyclists (V[Combining Dot Above]O2max, 4.49±0.35 L·min) completed three constant-load cycling trials to the limit of tolerance in a randomized, crossover de...

Maximal eccentric contractions induce an immediate strength loss that results from skeletal muscle damage, the symptoms of which can persist for several days after the exercise insult. The repeated bout effect (RBE) refers to the acute adaptive response precipitated from a single bout of eccentric contractions that result in an attenuated damage re...

Soccer matches are normally played over 90 minutes, however it is common for players to encounter a period of extra-time (ET; 30 min) during knockout competitions such as the FIFA World Cup. Despite the importance of ET in terms of deciding the match outcome, there is a paucity of data investigating responses to ET. Notably, no investigation has at...

This study investigated the test-retest reliability of physiological and performance responses to 120 min (90 min plus 30 min extra-time; ET) of the Soccer Match Simulation (SMS). Ten university-standard soccer players completed the SMS on two occasions under standardized conditions. Capillary and venous blood was taken pre-exercise, at half-time,...

Purpose: Unilateral strength training not only strengthens muscles on the trained side, but also the homologous muscles on the untrained side; however, the magnitude of this interlimb cross-education is modest. We tested the hypothesis that heightened sensory feedback by mirror-viewing the exercising hand would augment cross-education by modulatin...

Post-activation potentiation (PAP) is the increased involuntary muscle twitch response to stimulation following strong contraction. The enhancement to whole-body explosive muscular performance (PE) after heavy-resistance exercise is often attributed to modulations in neuromuscular function that are proposed to reflect PAP, but the evidence to suppo...

L-menthol stimulates cutaneous thermoreceptors and induces cool sensations improving thermal comfort, but has been linked to heat storage responses; this could increase risk of heat illness during self-paced exercise in the heat. Therefore, L-menthol application could lead to a discrepancy between behavioral and autonomic thermoregulatory drivers....

The development of central fatigue is prominent following exercise-induced hyperthermia, but the contribution of supraspinal fatigue is not well understood. Seven endurance-trained cyclists (mean ± SD peak O2 uptake, 62.0 ± 5.6 mL/kg/min) completed two high-intensity constant-load cycling trials (296 ± 34 W) to the limit of tolerance in a hot (34 °...

Exercise induced muscle damage (EIMD) is a well-investigated area, however there is a paucity of data surrounding the damage response in females. The aim of this study was to examine the damage responses from a sport-specific bout of repeated sprints in female athletes. Eleven well-trained females (mean ± SD; age 22 ± 3 y, height 166.6 ± 5.7 cm, ma...

Unaccustomed eccentric exercise using large muscle groups elicits soreness, decrements in physical function and impairs markers of whole-body insulin sensitivity; although these effects are attenuated with a repeated exposure. Eccentric exercise of a small muscle group (elbow flexors) displays similar soreness and damage profiles in response to rep...

Forceful, unilateral contractions modulate corticomotor paths targeting the resting, contralateral hand. However, it is unknown if mirror-viewing of a slowly moving but forcefully contracting hand would additionally affect these paths. Here we examined corticospinal excitability and short-interval intracortical inhibition (SICI) of the right-ipsila...

Background: The present study examined the agreement between fingertip-capillary and antecubital-venous measures of appetite-related peptides. Methods: Simultaneous fingertip-capillary and antecubital-venous blood samples were collected from 19 participants. Samples were obtained at baseline, 30, 60, 90 and 120 min following breakfast consumption f...

This study examined the reproducibility of fingertip-capillary derived appetite- and metabolism-related peptide expression following consumption of a light standardised breakfast meal. Eighteen healthy volunteers (age 23.1 ± 3.5 years, mass 69.3 ± 12.7 kg, BMI 23.1 ± 2.7 kg/m2) were studied on two occasions, separated by 7-days. Fingertip-capillary...

Purpose: Few studies have assessed neuromuscular fatigue after self-paced locomotor exercise; moreover, none have assessed the degree of supraspinal fatigue. This study assessed central and peripheral fatigue after self-paced exercise of different durations. Methods: Thirteen well-trained male cyclists completed 4-, 20-, and 40-km simulated time...

Purpose: This study aimed to determine the pattern of neuromuscular fatigability that manifests during repeated-sprint running exercise. Methods: Twelve male participants (mean ± SD: age, 25 ± 6 yr; stature, 180 ± 7 cm; body mass, 77 ± 7 kg), currently training and competing in intermittent sprint sports, performed a repeated maximal sprint runn...

Background / Purpose: The present study investigated the corticospinal and motor cortical responses to transcranial magnetic stimulation (TMS) in the left flexor carpi radialis (FCR) with and without viewing a mirror; 1) at rest, and 2) during a forceful shortening contraction of the right wrist flexors. Main conclusion: Viewing the mirror ima...

The purpose of the present study was to examine whether the expression of capillary-derived appetite peptides accurately reflects concentrations of their venous equivalents. Fingertip capillary (2×0.3 mL) and venous blood samples (2×4 mL) were collected simultaneously from 19 healthy adult volunteers [mean age 24.1 (SD 5.7) years, body mass 73.7 (S...

Previous research has suggested that the optimal pacing strategy for self-paced exercise lasting >4 min is a uniform distribution of work, but this posit is not well established for prolonged endurance events. This study examined the utility of even pacing during 20 km cycling time trials (TTs). Fifteen well-trained male cyclists ([Formula: see tex...

This study examined the effect of introducing either a male or female observer on the ratings of perceived exertion (RPE) and affect of male runners during a moderate intensity running task. 10 moderately active men completed three 20-min. moderate intensity running trials at 60% of their peak treadmill running speed. Each participant completed thr...

It has been proposed that an even-pacing strategy is optimal for events lasting <120 s, but this assertion is not well-established. This study tested the hypothesis that even-paced cycling is less challenging than self- or variable-paced cycling. Ten well-trained male cyclists (VO2max, 4.89 ± 0.32 L min(-1)) completed a self-paced (SP) 20-km time t...

The aim of this study was to investigate whether it was possible to reduce the time taken to complete a 4000-m cycling time trial by misleading participants into believing they were racing against a previous trial, when, in fact, the power output was 2% greater. Nine trained male cyclists each completed four 4000-m time trials. The first trial was...

Although pacing-related research is widely reported, no studies have described the consistency of pacing strategies or their associated energetic contributions. This study aimed to investigate the consistency of pacing and energetic outlay by establishing the typical within and between trial variations during simulated 4,000 m time trials. Fifteen...

The purpose of this study was to examine the relationship between fatigue-induced changes in running economy (RE) and muscular strength endurance (MSE). Ten well-trained male runners completed 2 runs of the same energy expenditure at 20%Δ VO(2) below LT. In the middle of the experimental condition (high intensity exercise [HIE]), there was a 4-minu...

The aim of the study was to assess the reproducibility of pacing strategy, physiological and perceptual responses during simulated 20-km cycling time trials. Seventeen well-trained male cyclists ([Formula: see text] = 4.70 ± 0.33 L min(-1)) completed three 20-km time trials on a Velotron Pro cycle ergometer within a maximum duration of 14 days. Dur...

The purpose of this study was to determine the reliability of an isokinetic endurance task. After habituation, 10 physically active males completed three trials of an isokinetic endurance task on nonconsecutive days. The task was performed on a Cybex Norm dynamometer. It consisted of 30 maximal, concentric and eccentric, contractions of the hip ext...

The aim of this study was to develop a laboratory-based treadmill simulation of the on-course physiological demands of an 18-hole round of golf and to identify the underlying physiological responses. Eight amateur golfers completed a round of golf during which heart rate (HR), steps taken, and global positioning system (GPS) data were assessed. The...

The glycemic index (GI) of dietary carbohydrates influences glycogen storage in skeletal muscle and circulating nonesterified fatty acid (NEFA) concentrations. We hypothesized that diets differing only in GI would alter intramuscular lipid oxidation and glycogen usage in skeletal muscle and liver during subsequent exercise. Endurance-trained indivi...

This study examined the effects of 3 recovery drinks on endurance performance following glycogen-depleting exercise. Nine trained male cyclists performed 3 experimental trials, in a randomized counter-balanced order, consisting of a glycogen-depleting trial, a 4-h recovery period, and a cycle to exhaustion at 70% power at maximal oxygen uptake. At...

The aim of this study was to compare the effects of two plyometric training techniques on power and agility in youth soccer players. Twelve males from a semiprofessional football club's academy (age = 17.3 +/- 0.4 years, stature = 177.9 +/- 5.1 cm, mass = 68.7 +/- 5.6 kg) were randomly assigned to 6 weeks of depth jump (DJ) or countermovement jump...