Viswanath Unnithan

University of the West of Scotland | UWS · School of Science and Sport

Age-related differences in twist may be mitigated with exercise training, although this remains inconclusive. Moreover, temporal left ventricular (LV) systolic twist mechanics, including early-systolic (twistearly), and beyond peak twist (twistpeak) alone, have not been considered. Therefore, further insights are required to ascertain the influence...

The question of how best to identify and develop youth soccer players has received considerable attention from the scientific community. Existing literature has, however, largely focused on male players, with comparatively little exploration of the specific approaches employed within women's soccer. Accordingly, we sought to investigate the key fac...

This study examined the relationships between the decision‐making performances of soccer referees and markers of physiological load. Following baseline measurements and habituation procedures, 13 national‐level male referees completed a novel Soccer Referee Simulation whilst simultaneously adjudicating on a series of video‐based decision‐making cli...

Aims Cardiac adaptations in elite, male adolescent youth soccer players have been demonstrated in relation to training status. The time course of these adaptations and the delineation of the influence of volatile growth phases from the training effect on these adaptations remain unclear. Consequently, the aims of the study were to evaluate the impa...

The transition of elite youth footballers through academy systems towards the first team is highly complex, competitive, and often unsuccessful. A myriad of factors including technical competence, physical prowess, and the development environment combine to determine youth player progression. Current research has focused on broad investigations of...

It has recently been identified that the assessment of peak periods of activity better considers the stochastic nature of match-play and the influence that contextual factors have on these peak periods. Limited research exists attempting to link the tactical and physical aspects of performance, especially in female players. Therefore, the current s...

Purpose: To gain knowledge on the beliefs and practices of football practitioners applying high-speed and sprint running exposure programming strategies. Methods: One hundred two football practitioners from 22 different countries participated in a study consisting of a survey including 5 domains: demographic and professional characteristics (Who...

Purpose: This study examined the interday reliability of a predetermined and a self-determined isometric-squat test among youth soccer players. Familiarization effects were evaluated to determine the minimum number of trials necessary to obtain consistent outputs. Finally, differences between protocols were evaluated. Methods: Thirty-one youth s...

Purpose This study explored the validity and reliability of the physiological and perceptual responses elicited during a novel treadmill-based Soccer Referee Simulation (SRS). Methods Following the collection of baseline measures and habituation procedures, eight sub-elite soccer referees completed a single trial of the SRS whereby measures of hea...

There is an increase in the prevalence of elite youth sports academies, whose sole aim is to develop future elite athletes. This involves the exposure of the child and adolescent athlete to high-volume training during a period of volatile growth. The large amount of data in this area has been garnered from the resting echocardiographic left ventric...

Background Sided games (i.e., small sided, medium sided, large sided) involve tactical, technical, physical, and psychological elements and are commonly implemented in soccer training. Although soccer sided-games research is plentiful, a meta-analytical synthesis of external load exposure during sided games is lacking. Objective The objective of t...

Purpose: This study explored the validity and reliability of the physiological and perceptual responses elicited during a novel treadmill-based Soccer Referee Simulation (SRS). Methods: Following the collection of baseline measures and habituation procedures, eight sub-elite soccer referees completed a single trial of the SRS whereby measures of he...

This study sought to: (1) document the multifaceted training practices of soccer officials in relation to their role and officiating category; and (2) explore the association between the officials’ training practices and perceptions of the attributes pertinent to optimal performance. Field referees and assistant referees at officiating categories 1...

Background: Sided-games (i.e., small- [SSG], medium- [MSG], large-sided [LSG]) involve tactical, technical, physical and psychological elements and are commonly implemented in soccer training. Although soccer sided-games research is plentiful, a meta-analytical synthesis of external load exposure during sided-games is lacking. Objective: The objec...

Background: The SARS-COV2 agent initiated a global pandemic. The initial response to the pandemic was severe disruption to the public and private sector including sports. The resultant was that soccer clubs had to prescribe that the players trained in isolation for a prolonged period of time in an attempt to maintain fitness. The aim of the presen...

It is unclear what the effect of long‐term, high‐volume soccer training has on left ventricular (LV) function during exercise in youth soccer players. This study evaluated changes in LV function during submaximal exercise in a group of highly‐trained male soccer players (SP) as they transitioned over a three‐year period from pre‐adolescent to adole...

Introduction The aims of this study were 1) to assess if talented players can be identified within possession-based small-sided games (SSG), and 2) to determine if, decision making, physical, and time-motion characteristics correlated to success in a possession-based SSG. Methods Eight, highly-trained U10 soccer players (Mean ± SD; age: 10.3 ± 0.2...

INTRODUCTION: Simulation protocols that mimic match play are often utilised to circumvent the challenges of conducting research in the actual performance setting (1). In addition to negating the contextual variables and large levels of variability that confound match play data (2), simulation protocols enable physiological responses to be monitored...

Cardiac modifications to training are a product of the genetic pre-disposition for adaptation and the repetitive haemodynamic loads that are placed on the myocardium. Elite pre-adolescent athletes are exposed to high-intensity training at a young age with little understanding of the physiological and clinical consequences. It is unclear how right v...

Female soccer has seen a substantial rise in participation, as well as increased financial support from governing bodies over the last decade. Thus, there is an onus on researchers and medical departments to develop a better understanding of the physical characteristics and demands, and the health and performance needs of female soccer players. In...

We quantified on pitch external loading of English Premier League (EPL) academy soccer players (n=76; U12-U18 age groups) over an entire competitive season. Mean accumulative weekly duration and total distance, respectively, was similar in the U12 (329±29 min; 19.9±2.2 km), U13 (323±29 min; 20.0±2.0 km) and U14 (339±25 min; 21.7±2.0 km; P>0.05 for...

Considering the perceived benefit of early recruitment and the time and resources spent developing youth players, individuals released from talent development programmes are often re-recruited by rival academies. However, due to the contractual nature of many talent development programmes, limited empirical data exists on players deselected from (o...

Significant structural, developmental, and financial constraints exist in Scottish soccer that may predicate a different approach to talent identification and development. To our knowledge, no published reports exist evaluating the prevalence of the relative age effect (RAE) in Scottish soccer players. Consequently, the aim of this study was to inv...

The aim of this study was to compare internal and external load profiles of different game profile-based training (GPBT) formats among elite young football players. Twenty-one participants (age: 18.7 ± 0.6 years) performed three sessions of three GPBT formats, which were matched for training volume but structured with different high-speed running a...

To evaluate changes achieved in whole-body and regional (upper limbs, lower limbs, and trunk) estimates of body composition, twenty professional male soccer players (7 defenders, 7 midfielders, 6 forwards) underwent dual-energy x-ray absorptiometry (DXA) analysis at the beginning and end of pre-season. Measures included: mass, fat mass (FM), fat-fr...

PurposeThe interaction of ageing and exercise training status on left-ventricular (LV) peak strain is unclear. Additionally, strain analysis across the entire cardiac cycle facilitates a more detailed assessment of deformation, yet this has not been implemented to characterize the ageing LV and in association with training status. This study invest...

We investigated the cardiorespiratory responses to semi-supine exercise with (SS+45°) and without (SS-0°) a left-lateral tilt in 15 adults at fixed power output (70 W) and matched heart rates. At 70 W, oxygen uptake and heart rate reduced from upright to SS-0° then increased to SS+45° (p < 0.05). At matched heart rates, oxygen uptake and efficiency...

To develop and assess the validity of the Referee Training Activity Questionnaire (RTAQ), a systematic process was employed: 1) item generation; 2) assessments of content and face validity; and 3) assessments of criterion validity. In stage 1, items were generated following semi-structured interviews with an expert panel (n = 8). Following content...

FC Barcelona is a multi-sport organization that adopts a talent identification approach that emphasizes the technical, psychological, and perceptual–cognitive attributes. It is unclear within this type of sporting selection model whether the relative age effect (RAE) exists. Consequently, the aim of the study was to evaluate the RAE across multiple...

Purpose: To inform the energy requirements of highly trained adolescent soccer players, total energy expenditure (TEE) was quantified in academy soccer players from the English Premier League (EPL). Methods: Twenty-four male adolescent soccer players from an EPL academy (n=8 U12/13; n=8 U15; n=8 U18) were assessed for baseline maturity (maturity...

Isokinetic strength screening is utilized in professional soccer. However, there has been little research on the interaction between seasonal changes in players' peak torque (PT) and injury incidence. Twenty-five (age 16.5 ± 0.68 years) professional youth soccer players participated in the study. Bilateral isokinetic concentric (CON) and eccentric...

For the first time we aimed to: (1) assess fat-free mass (FFM) and RMR in youth soccer players, (2) compare measured RMR to estimated RMR using previously published prediction equations, and (3) develop a novel population-specific prediction equation. In a cross-sectional design, 99 males from a Premier League academy underwent assessments of body...

Aims: This study aimed to evaluate left ventricular (LV) structure, function and mechanics, in highly-trained, pre-adolescent soccer players (SP) compared to age- and sex-matched controls (CON). Design: The study design was a prospective, cross-sectional comparison of LV structure, function and mechanics. Methods: Twenty-two male SP from two profes...

The present study was designed to investigate and compare the effects of game profile-based (GPBT) and small-sided games (SSGs) training on physical performances of elite youth soccer players during the in-season period. Twenty young soccer players (18.6 ± 0.6) were randomly assigned to either GPBT or SSGs protocols performed twice a week for 8 wee...

Purpose: To examine the impact of environmental heat stress conditions on physical and technical football match-play characteristics. Method: Data from 42 matches of 9 outfields, professional football players were collected in temperatures ranging from 13°C to 37°C and relative humidity ranging from 11% to 83%. Individual player data were only incl...

It is unclear, what the underlying cardiovascular mechanisms are that give rise to the high level of aerobic fitness seen in youth soccer players. The aim of the study was to evaluate global and regional markers of systolic and diastolic function in a group of pre‐adolescent soccer players during an incremental exercise test. Twenty‐two, male socce...

Purpose: To examine the reliability of heart rate (HR) measures obtained during a 6-min Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1), and following a 3-min passive recovery, within a group of highly trained youth soccer players Methods: Eight players completed three separate 6-min Yo-Yo IR1 tests, with a passive recovery, over a 2-week peri...

Background The objective of this study was to investigate left ventricular (LV) circumferential strain responses to incremental cycling and isometric knee extension exercises. Methods Twenty‐six healthy male participants (age = 30 ± 6 years) were used to study LV global (GCS) and regional circumferential strain at the apex (ACS) and base (BCS) dur...

Purpose: The purpose of the study was to assess the validity, objectivity, and reliability of a Soccer-Specific Behaviour Measurement Tool (S-SBMT) in relation to the soccer philosophy of a Category One Premier League soccer academy. Methods: A 30 minute, 8 vs. 8 small-sided game (SSG), played by the U12 squad of the participating academy was used...

Purpose: The purpose of the study was to examine differences in measures of cardiorespiratory fitness and determinants of running economy with respect to maturity status in a group of highly trained youth soccer players. Methods: A total of 21 highly trained youth soccer players participated in this study. On separate visits, players' peak oxyge...

To assess the between-game variation in measures of physical performance during 11 v 11 soccer match-play, over a short period of time, in highly trained youth soccer players. A single cohort observational study design was employed. Physical match performance data were collected from 17 male, highly trained youth soccer players (age: 13.3 ± 0.4 y)...

There were two aims of this study: first, to investigate physical fitness and match performance differences between under-16 (U16) and under-18 (U18) female basketball players, and second, to evaluate the relationship between physical fitness and game-related performances. Twenty-three young, female, elite Spanish basketball players (16.2 1.2 years...

Purpose: To examine the relationship between oxygen uptake kinetics (VO2 kinetics) and physical measures associated with soccer match play, within a group of highly trained youth soccer players. Methods: Seventeen highly trained youth soccer players (age: 13.3 ± 0.4 year, self-assessed Tanner stage: 3 ± 1) volunteered for the study. Players init...

The aim of this study was to evaluate physiological and technical attributes of prepubertal soccer players during multiple small-sided games (SSGs), and determine if SSGs can act as a talent identification tool. Sixteen highly trained U10 soccer players participated and separated into two groups of eight. Each group played six small-sided (4 vs. 4)...

The primary objective of the present study was to evaluate the agreement between the dominant leg (DL) (determined subjectively) and the stronger leg (SL) (determined via a functional test) in a group of basketball and volleyball players. The secondary objective was to calculate lower limb neuromuscular asymmetry when comparing the DL vs the non-do...

Background: To evaluate whether physical performance characteristics could be a better predictor than technical skills in determining the technical level of county soccer players in a match situation. Methods: With institutional ethics approval, 25 male youth soccer players aged 16-18.5 years from a professional soccer academy in South East Asia...

Clinical exercise physiologists and physicians administering stress tests in the young have utilized oxygen pulse as a surrogate measure of stroke volume. It is important to recognize 1) the accuracy of O2 pulse in predicting maximal stroke volume during exercise, and 2) the normal pattern of O2 pulse during a progressive exercise test. This study...

Little evidence exists with regard to changes in cardiac strain that occur during submaximal exercise in young males. The aims of the study were to evaluate the changes that occur in longitudinal (L), radial (R), and endocardial circumferential (EC) strain during submaximal upright cycle ergometry and to examine the test–retest reproducibility of t...

There is a real possibility that physical activity endangers life, due to sports practice or a mismanaged disease, but is not always taken into account. Deaths while practicing sports and risk of a fatal outcome are low, and have been associated with cardiovascular problems. However, diseases of other biological systems, as well as an individual pr...

Unlabelled: Little evidence exists with regard to the effect that exercise training has upon oxygen uptake kinetics in adolescent females. Purpose: The aim of the study was to compare [Formula: see text] and muscle deoxygenation kinetics in a group of trained (Tr) and untrained (Utr) female adolescents. Method: Twelve trained (6.4 ± 0.9 years...

The effects of a short, high-intensity bout of exercise on cardiac systolic and diastolic function are not well understood in adolescent athletes. Consequently, the aims of the study were to evaluate global left ventricular (LV) systolic and diastolic function, as well as segmental wall motion responses (cardiac strain), prior to as well as 45 and...

A paucity of literature exists with regard to research on nutrition for the pediatric athlete. This lack of research makes the development of specific nutritional recommendations for young athletes problematic. This issue is made difficult by the macro- and micronutrient intake required for growth and development in conjunction with that required f...

Background and aim: Physical frailty has been regarded as a precursor state to disability and dependence on others for daily activities. Frail individuals are considered to be the group of patients that presents the most complex and challenging problems to health care professionals. The purpose of this study was to evaluate whether a 12-week funct...

Understanding cardiac responses to exercise in healthy subjects is important in the evaluation of youth with heart disease. This review article incorporates previously published original research from the authors' laboratory to examine changes in stroke volume during progressive exercise which are consistent with a model in which circulatory respon...

Assessment of myocardial contractile function during exercise is important in gaining an understanding of the normal mechanics of the cardiovascular responses to exercise stress. Such insights are important in identifying determinants of cardiovascular fitness in athletes as well as assessing patients with heart disease. While obtaining such measur...

Abstract The purpose of this review article was firstly to evaluate the traditional approach to talent identification in youth soccer and secondly present pilot data on a more holistic method for talent identification. Research evidence exists to suggest that talent identification mechanisms that are predicated upon the physical (anthropometric) at...

Objective: To compare the phase II oxygen uptake time constant (τV'O(2)) and V'O(2) mean response time (V'O(2)MRT) in overweight (OW) and non-OW (NO) children during moderate intensity exercise. Design: Between subjects where participants completed a maximal ramp exercise test on an electromagnetically braked cycle ergometer to determine peak V'...

Aim. To evaluate the effects of aquatic (AQ) compared to a land-based (LB) intervention programs on metabolic cost of walking (MCW), gross motor function and locomotor performance in children with cerebral palsy (CP). Methods. Eleven children with spastic diplegic CP completed this study, six in the AQ (5.2 ± 1.45 yrs) and five in the LB group (4.1...

Article Title: Orthostatic Effects on Echocardiographic Measures of Ventricular Function (Echocardiography 2012;29:522).

Orthostatic‐induced alterations in Doppler echocardiographic measures of ventricular function have not been well‐defined. Identifying such changes may provide useful insights regarding the responses of these measures to variations in ventricular loading conditions. Standard assessment of mitral inflow velocity and tissue Doppler imaging (TDI) of le...

A recent report indicated that variations in myocardial functional (systolic and diastolic) responses to exercise do not contribute to inter-individual differences in aerobic fitness (peak VO(2)) among young males. This study was designed to investigate the same question among adolescent females. Thirteen highly fit adolescent football (soccer) pla...

This study was designed to examine time-of-day effects on markers of cardiac functional capacity during a standard progressive cycle exercise test. Fourteen healthy, untrained young males (mean ± SD: 17.9 ± 0.7 yrs of age) performed identical maximal cycle tests in the morning (08:00-11:00 h) and late afternoon (16:00-19:00 h) in random order. Card...

The relationship between physical activity in school children, academic performance and their perceptual-motor skills is unclear. The aim of this study was to look at the relationship between perceptual-motor and cognitive skills. 487 subjects (249 girls, 238 boys) from 6 public centres of primary and secondary schools in the Barcelona area (Spain)...

Inspiratory muscle training (IMT) has been shown to improve inspiratory muscle function, lung volumes (vital capacity [VC] and total lung capacity [TLC]), work capacity, and power output in people who are healthy; however, no data exist that demonstrate the effect of varying intensities of IMT to produce these outcomes. The purpose of this study wa...

Previous studies have demonstrated faster pulmonary oxygen uptake (VO2) kinetics in the trained state during the transition to and from moderate-intensity exercise in adults. Whilst a similar effect of training status has previously been observed during the on-transition in adolescents, whether this is also observed during recovery from exercise is...

Evidence-based recommendations regarding which exercise tests to use in children and adolescents with cerebral palsy (CP) are lacking. This makes it very difficult for therapists and researchers to choose the appropriate exercise-related outcome measures for this group. This study aimed to identify a core set of exercise tests for children and adol...

The purpose of this study was to evaluate whether a 12-wk functional circuit-training program (FCT) could alter markers of physical frailty in a group of frail community-dwelling adults. Fifty-one individuals (31 women, 20 men), mean age (± SD) 84 (± 2.9) yr, met frailty criteria and were randomly assigned into groups (FCT = 26, control group [CG]...

Ventricular systolic functional response to exercise has been reported to be superior in adult men compared to women. This study explored myocardial responses to maximal upright progressive exercise in late pubertal males and females. Doppler echocardiographic techniques were utilized to estimate myocardial function response to a bout of progressiv...

The purpose of this study was to evaluate whether a 12-wk functional circuit-training program (FCT) could alter markers of physical frailty in a group of frail community-dwelling adults. Fifty-one individuals (31 women, 20 men), mean age (± SD) 84 (± 2.9) yr, met frailty criteria and were randomly assigned into groups (FCT = 26, control group [CG]...

Whilst endothelial dysfunction is associated with a sedentary lifestyle, enhanced endothelial function has been documented in the skin of trained individuals. The purpose of this study was to investigate whether highly trained adolescent males possess enhanced skin microvascular endothelial function compared to their untrained peers. Seventeen high...

Exercise training results in a speeding of pulmonary oxygen uptake (VO2) kinetics at the onset of exercise in adults; however, only limited research has been conducted with children and adolescents. The aim of the present study was to examine VO2 and muscle deoxygenation kinetics in trained and untrained male adolescents. Sixteen trained (15 +/- 0....

The purpose of the study was to determine the degree to which scores of a modified version of the 'Timed Get Up and Go' test (TGUG) were associated with other measures of functional performance. Thirty-seven community-dwelling older women (72.3+/-5.5 years) volunteered to participate. Subjects were assessed when performing the modified TGUG test. C...

The extent that enhanced ventricular function contributes to superior aerobic fitness of trained athletes is unclear. This study compared cardiovascular responses to progressive cycle exercise in 12 adolescent soccer players and 10 untrained boys with assessment of ventricular inotropic and relaxation properties by Doppler ultrasound techniques. Re...