Santiago Zabaloy

University of Flores (U of F) · Facultad de Actividad físca y deportes

BACKGROUND: The use of force-velocity imbalance (Fvimb) has been proposed as an effective method for prescribing training loads aiming to enhance physical performance. OBJECTIVE: This study aimed to analyse the effects on lower body strength, jump and sprint performance of different indi-vidualised resistance training (RT) programmes based on Fvimb...

This study aimed to investigate the relationship between a specific isometric-strength sprint test (SIST) and unresisted maximum velocity (Vmax), sprint times across different loading conditions, and the velocity loss (Vloss) loads required to achieve each intended Vloss condition during resisted sprint training (RST) in rugby players. Additionally...

Purpose: We tested the differences in maximum strength and various parameters of sprint performance between youth backs and forwards. Additionally, we examined the associations among various strength-sprint measures, as well as between unresisted and heavy-resisted sprints. Methods: Thirty-two youth rugby players were assessed at the beginning of t...

Post-activation performance enhancement (PAPE) is a key objective following regular warm-up routines, especially in sports that rely heavily on sprinting speed and power. Rugby is a team sport characterized by a range of repeated high-intensity efforts, irrespective of positional roles or match demands. In this study, we examined and compared the e...

Zabaloy, S, Freitas, TT, Alcaraz, PE, Gálvez-González, J, Pereira, LA, Comyns, T, Loturco, I, and Healy, R. Relative acceleration and maximum velocity in rugby players according to age category and playing position. J Strength Cond Res XX(X): 000-000, 2024-This study aimed to (a) assess the intrasession reliability of the acceleration time constant...

This is the first study to assess longitudinal changes in anthropometric, physiological, and physical qualities of international women’s rugby league players. Thirteen forwards and 11 backs were tested three times over a 10-month period. Assessments included: standing height and body mass, body composition measured by dual x-ray absorptiometry (DXA...

We examined the effectiveness of two different jump-squat (JS) loading ranges on the physical performance of rugby players. Twenty-eight elite male rugby players were divided into two JS training groups: a light-load JS group (“LJS”; JS at 40% of the one-repetition maximum [1RM] in the half-squat (HS) exercise) and a heavy-load JS group (“HJS”; JS...

Purpose Soccer is a complex sport that depends on several physical performance and technical-tactical factors. Therefore, we aimed to: i) analyze the differences in physical, technical, and tactical performance of one international team when competing against opponents divided by their world ranking (i.e., higher ranked [HR] and lower ranked [LR])...

This is the first study to assess longitudinal changes in anthropometric, physiological, and physical qualities of international women’s rugby league players. Thirteen forwards and 11 backs were tested three times over a 10-month period. Assessments included: standing height and body mass, body composition measured by dual x-ray absorptiometry (DXA...

Objectives: To explore the differences and correlations in the Y-Balance Test (YBT) scores, ankle-dorsiflexion range of motion (ADFROM), single-leg drop jump (SLDJ) and single-leg hop for distance (SLHD) in amateur male rugby players by playing positions and limb dominance. Design: Cross-sectional study. Setting: Argentinian amateur rugby club. Par...

In the final part of this three-article collection on the training strategies of Brazilian Olympic sprint and jump coaches, we provide a detailed description of the resistance training methods and exercises most commonly employed by these speed experts. Always with the objective of maximizing the sprint and jump capabilities of their athletes, thes...

This study aimed to determine, through the use of a highly sensitive statistical tool, whether real changes in performance were present; and compare the rates of meaningful variations in strength, speed, and power parameters at different time-points during the competitive season in national team rugby players. Thirty-two players were assessed 5 tim...

Introduction: Warm-up is a primordial element to optimise sport performance in both training and competitions. The main objective of this study was to compare the acute effect of two warm-up protocols for physical and technical-decisional performance in U16 football players. Material and Methods: We applied an integrated warm-up protocol (IWP) of 5...

This is the second article in a three-article collection regarding the plyometric, speed, and resistance training practices of Brazilian Olympic sprint and jump coaches. Here, we list and describe six out of the ten speed training methods most commonly employed by these experts to enhance the sprinting capabilities of their athletes. Maximum speed...

Objective: To examine the associations between the Functional Movement Screening (FMS™) scores and asymmetries between limbs in the different tasks with non-contact injuries in senior amateur rugby union players. Method: The design was a prospective cohort study. Sixty-eight ( n = 68) male senior amateur rugby players completed the FMS™, which asse...

The maximum velocity achieved during sprinting is a crucial aspect in various sports. Therefore, practitioners utilize various devices, such as laser or radar guns, timing gates, and Global Positioning Systems (GPS), to assess sprint performance. While high speed cameras are considered the most accurate equipment for assessing maximum velocity (Vma...

Purpose: To investigate the relationships between a series of direct and indirect measures of linear and multidirectional speed performance in elite female rugby sevens players. Methods: Nineteen players from the Brazilian national team performed 40-m linear sprint and 505 change-of-direction (COD) tests on the same day. Based on the linear spri...

Purpose To examine the differences in body composition and physical performance in academy under-16 (U16) soccer players, born in the first (i.e., early born, EB) and second semester (i.e., late born, LB) of the year; and analyze the associations of relative age (RA) and biological maturation (peak height velocity [PHV]) with body composition and p...

This study aimed to compare body composition and physical performance between U-17 and U-19 rugby players (forwards and backs), and examine the correlations among body composition, relative strength, jump, and sprint performance in both playing positions. Fifty-two male adolescent rugby players (mean ± SD: age, U-17: 16.2 ± 0.6 and U-19: 18.09 ± 0....

(1) Objetive: Compare the internal load (ILO), external load (ELO) and wellness (WS) between official preparation friendly matches (FM) and France 2019 women world cup (WWC) matches in female soccer players. (2) Methods: Ten field players of the Chilean national football team (age 27 ± 3.4 years, height 162.8 ± 4.32 cm, weight 60.5 ± 4.6 kg, fat pe...

ABSTRACT Objectives: To analyse match and training injury incidence rates and burden from pre-(2019) and post- COVID-19 (2021) seasons; To analyse injury related variables as mechanisms, type, body locations, severity and the differences of the most common injuries according to playing positions. Design: An observational study was performed accordi...

The aims of this study were to: 1) examine the effects of a 6-week sand training program including both sprint and jump exercises on the speed-related and vertical jump performance of elite young soccer players; and 2) compare the changes induced by a sand training scheme with those induced by a similar training program (in terms of volume, intensi...

This study aimed to compare the changes in body composition and physical qualities of under 19’ s backs and forwards during the season (i.e . from pre-season [Pre-S] to end-season [End-S]). Twenty-seven male youth rugby union players (mean ± SD: age, Forwards [n = 11]: 17.5 ± 1.2 and Backs [n = 16]: 17.0 ± 0.9 years) participated in this study. Par...

The strength deficit (SDef) is an important indicator of athletic performance [1,2], and it was previously reported to be able to discriminate between fast and slow athletes [1]. For example, SDef was lower when sprinters were compared to elite rugby players [1] and amateur rugby backs also demonstrated a lower SDef versus forwards [2]. Nonetheless...

PurposeSpecial tactical units differ from other police departments, for having more physically demanding tasks and occupations. Therefore, the aim was to analyze: (i) the differences in anthropometrics, body composition, and physical performance variables between those officers with the highest and lowest lean mass (LM) and fat mass (FM); and (ii)...

The aim of this study was to compare the peak-force (PF), peak-power (PP), and peak velocity (PV) outputs produced during half-squat (HS) and jump-squat (JS) exercises executed at 20, 40, 60, and 80% of one-repetition maximum (1RM) in the HS (HS 1RM); and to compute and compare the strength deficit (SDef) achieved in these exercises across these lo...

The Argentine Rugby Union is a top-tier rugby nation (ranked 8th according to World Rugby), with the Buenos Aires Rugby Union being the largest competitive league. To date, the training practices of Argentinian rugby strength and conditioning coaches have not yet been documented and analyzed. We used an online survey to characterize the training an...

This study aimed to: i) analyze the differences in anthropometric, body composition, physical, and technical parameters in elite female football players across distinct playing positions; ii) examine the correlations between kicking velocity (KV) and physical performance, and the relationships between linear sprint and curve sprint (CS) times. Twen...

Sprinting is a key component for many individual and team sports. Therefore, to enhance sprint performance, various training methods are widely used by coaches and practitioners, including maximum sprint speed and resisted sprint training. Resisted sprinting with sled towing is a method that has recently received considerable attention from the spo...

The COVID-19 pandemic led to an unusual situation in sports. Players were forced to stay at home for an undefined period of time and not allowed to use any training facilities or even exercise outdoors. Therefore, this study aimed to examine the effects of the COVID-19 lockdown on physical performance and body composition in elite female football p...

The COVID-19 pandemic led to an unusual situation in sports. Players were forced to stay at home for an undefined period of time and not allowed to use any training facilities or even exercise outdoors. Therefore, this study aimed to examine the effects of the COVID-19 lockdown on physical performance and body composition in elite female football p...

The aims of this study were twofold: to compare the strength-related performance between young forwards and backs rugby players and to examine the correlations between strength deficit (SDef), strength parameters, and sprint and jump performance. Fifty-seven male rugby players (mean 6 SD: age, 17.4 6 1.3 years) performed anthropometric and body com...

Rugby Union is a physically demanding game, in which well developed physical qualities (eg. body size, strength, speed and aerobic fitness) are important attributes for player success (1,2). Hence, due to the demands of rugby union, the development of these physical qualities and an optimal body composition are all required to enable the completion...

Purpose: To compare the strength, speed, and power performance of elite sprinters with and without visual impairment. Methods: Twelve elite able-bodied sprinters and 15 Paralympic sprinters with visual impairment took part in this study. Sprinters from both groups performed the following tests: squat and countermovement jumps, maximum bar-power...

1) Background: An improved understanding of soccer players' match-related physical performance and recovery may help conditioning programs and re-warm up strategies to increase team performance during official competitions. Therefore, the aim of this study was to analyze the acute effects of 45 min of official competition (first half in matches) on...

BACKGROUND: This study examined the differences in physical and anthropometric traits between specific playing positions (i.e., forwards: front row, second row, back row; backs: half backs, centers, wings/fullbacks) in amateur rugby players and analyzed the magnitude of correlations among jump, sprint, and strength measures in forwards and backs. M...

The aim of this study was to explore the anthropometric profile and evaluate physical fitness variables of the members of the Chile women's national football team based on their playing positions. Fifty football players participated in this study, which was carried out during the period of training for the France 2019 Women's World Cup and the Japa...

Acknowledgments We would like to acknowledge the help of the clubs and participants who took part in the current study. Abstract The purpose of this study was to investigate the interval in which male rugby union players reach maximum speed in a 50 m sprint according to age categories and playing positions. This study also aimed to establish the op...

En la presente Tesis doctoral se tratarán una serie de problemáticas relacionadas con el entrenamiento de la velocidad de sprint en el rugby. Todas ellas están estrechamente relacionadas entre sí, ya que plantean la necesidad de establecer métodos de entrenamiento y evaluaciones específicas para los jugadores de rugby y en relación con el puesto es...

This study assessed the validity of 5-m (TG5) and 10-m (TG10) split times measured with timing gates to estimate maximum sprint speed (MSS) against a criterion measure radar gun (RG) during the maximum velocity phase of a 30-m sprint. Nineteen amateur rugby players performed two 30-m sprints. The timing gates were placed at the starting line and at...

This study aimed to compare muscle activity, leg stiffness, and kinematics (contact and flight time [FT], stride length and frequency, and trunk angle [TA]) of unloaded sprinting to resisted sprint (RST) using different loads. Twelve male rugby players (age: 23.5 ± 5.1 years; height: 1.79 ± 0.04 m; body mass 82.5 ± 13.1 kg) performed 30-m sprints u...

This study aimed to analyze the differences in force-velocity profile and sprint, strength and jump performance according to playing position, and to examine the relationships between these fitness parameters within specific rugby playing positions. Fifty-one male rugby players (27 backs, 24 forwards) were assessed in their force-velocity profile,...

We examined the effects of five loading conditions (0%, 20%, 40%, 60%, and 80% of body-mass [BM]), on resisted sprint performance and kinematics in male rugby players over different distances. Ten players from the Brazilian National Team (20.1±3.3 years; 88.7±18.8 kg; 178.3±6.2 cm) performed 20-m sprints under the five loading conditions. Sprint ti...

The purpose of this paper is to design a suitable device for the evaluation of the “place-kick” gesture in rugby as well as to provide to the coach a useful tool which will help him in his everyday practice sessions; this tool should also help him to analyze these gestures at their key points. Another goal will be establish the relationships betwee...