Valentín E Fernández-Elías

• PhD
• Professor at Rey Juan Carlos University

As sports nutrition research evolves, a growing body of evidence highlights the importance of sex-based differences in responses to dietary interventions for athletic performance [...]

Background: Football is an intermittent effort sport that demands high intensity power performance. To enhance this performance before training and competition, a short and intense warm-up is convenient. However, there is a gap between the performance reached in the warm-up and the performance needed during competition. Thus, the aim of this study...

Eating disorders (EDs) are a significant health issue in combat sports. This study investigated the differences between the different types of female wrestlers and the frequency at which EDs occur in the elite population, and it also sought to establish which factors are predictors of EDs. This study was comprised of 22 elite, female wrestlers who...

Paddle tenis has experienced significant growth in recent years, becoming one of the most popular and globally expanding sports. This study aims to examine the physiological performance and subjective perception of stress and fatigue in top-20 padel players during matches. Seven elite players participated in the study. Various variables were evalua...

Abstract: Many studies have tested intermittent fasting (IF) in athletes, but its effects on female CrossFit athletes remain relatively unexplored in the existing literature. The aim of this study was to evaluate and compare the effects of 24-h IF on the physical performance of female CrossFit practitioners. Eleven female CrossFit athletes (age: 30...

Hyperthermia accelerates dehydration and can lead to a glycolysis malfunction. Therefore, to deeply understand the relationship between dehydration and hyperthermia during exercise, as well as in the recovery time, there might be important factors to improve athletic performance. A systematic review was carried out in different databases using the...

The vertical jump is one of the most used testing movements to assess athlete's physical performance and fatigue status in several sports. However, low-cost, portable, field-based, and reliable methods are needed to measure jumping performance. The aim of the current investigation was to assess the validity and reliability of a new photoelectric ce...

Most intervention studies investigating the effects of ergogenic aids (EAs) on sports performance have been carried out in the male population. Thus, the aim of this systematic review and meta-analysis was to summarize the effects in the existing literature of EAs used by female athletes on performance. A literature research was conducted, and a de...

The aim of the present research was to analyse modifications in the autonomic stress response of Physiotherapy students undergoing a 12-scenario Objective Structured Clinical Evaluation (OSCE). A total of 86 last year students of the Physiotherapy bachelor’s degree (27.29 years (SD = 6.66); 36 females and 50 males) randomly assigned were monitored...

Whole-body electromyostimulation (WB-EMS) training is effective in improving training adaptation. However, WB-EMS may have side effects and contraindications that can lead to excessive muscle damage and physiological impairment. This randomized crossover study aimed to analyze the acute effects of WB-EMS on muscle damage, autonomic modulation and p...

Previous studies have shown that polyphenol consumption enhances recovery of the muscle after exercise-induced muscle damage (EIMD). However, EIMD markers have not been studied by sport type. The main aim of this research was to perform a systematic review to determine the efficacy of polyphenolic consumption in increasing muscle recovery for perfo...

An 18-year-old male motorcycle racer, who was a participant in the FIM Road Racing World Championship and had a history of Ornithine Transcarbamylase deficiency, developed nausea and dizziness while driving his motorcycle and became unconscious right after he stopped at the box. He was rapidly attended to by the medical personnel of the circuit, an...

The aim of the present research was to analyse modifications in the autonomic stress response of Physiotherapy students undergoing a 12-scenario Objective Structured Clinical Evaluation (OSCE). A total of 86 last year students of the Physiotherapy bachelor’s degree ( 27.29 years (SD = 6.66).; 36 females and 50 males) randomly assigned were monitore...

The aim of the present research was to analyse modifications in the autonomic stress response of Physiotherapy students undergoing a 12-scenario Objective Structured Clinical Evaluation (OSCE). A total of 86 last year students of the Physiotherapy bachelor’s degree ( 27.29 years (SD = 6.66).; 36 females and 50 males) randomly assigned were monitore...

Many sports and recreational strength training coaches consider movement velocity essential to improve performance, and velocity-based training has gained attention over the past decade. Furthermore, there is a lack of low-cost, easy to use, and reliable methods to measure movement velocity. Therefore, this current research aims to analyze the vali...

Objective: The COVID-19 pandemic is now a major global health issue and quarantine is being applicated worldwide as a suppression measure. The aim of this study was to analyse the psychological and behavioural modifications associated with the first phase of the confinement period in Spanish population. Material and method: Variables of anxiety, sl...

The aim of this research was to analyze the effect of studying a single or double degree in the psychophysiological stress response and academic performance of university students in their bachelor’s thesis defense. We analyzed the autonomic stress response, cortical arousal, subjective distress perception, and the sense of objective and subjective...

Introduction: Elevated plasma α-klotho (αKl) protects against several ageing phenotypes and has been proposed as a biomarker of a good prognosis for different diseases. The beneficial health effects of elevated plasma levels of soluble αKl (SαKl) have been likened to the positive effects of exercise on ageing and chronic disease progression. It has...

The aims of this study were: i. to analyze the effect of nationality on the psychophysiological stress response of physiotherapy last year students in their final degree dissertations; and ii. to analyze the relationship between the stress response and academic results according to nationality. We evaluated the autonomic stress response, cortical a...

Objective Beetroot juice is a source of dietary nitrate (NO3-) recognized as a potential ergogenic aid to enhance tolerance during endurance exercise of submaximal-to-maximal intensity. However, little is known about the effects of beetroot juice on exercise performance in intermittent sports such as tennis. The present study aimed to determine the...

Stress is regulated by the autonomous nervous system, increasing the sympathetic modulation when a threat is perceived. A multifactorial response usually leads to significant behavioural modifications and alterations on homeostasis and physical and psychological status. Moreover, stress is an emotional response that can lead to psychosocial and psy...

The objective of this study was to analyse the effect of final dissertation defense language in the autonomic stress response and cortical arousal of Physiotherapy students. We analysed in 110 students divided in 2 groups: native language (83) and non-native language (27), the autonomic stress response in four different moments of the dissertation...

Introduction Speleology/Caving is a recreational outdoor activity that has drawn an increasing number of participants in recent years, but there is little information on the physiological and psychological demands of this outdoor activity. This research aimed to analyze the psychophysiological response of novice cavers to a caving route. Methods M...

Final dissertation is considered one of the most stressful situations in university studies, but the stress response and its incidence in academic achievement is poor knowledge. The aim of the present research was to analyze the effect of the psychophysiological stress response of physiotherapy last year students in his final degree dissertation pe...

Introduction The study of chronic and acute responses when exposed to extreme, aggressive and stressful environments, such as in combat environments, is becoming increasingly popular as such information leads to better optimisation of soldiers’ physical and psychological performance, as well as mission effectiveness and efficiency. Due to internal...

Beetroot juice (BJ) contains high levels of inorganic nitrate (NO3−) and its intake has good evidence in increasing blood nitrate/nitrite concentrations. The ingestion of BJ has been associated with improvements in physical performance of endurance sports, however the literature in intermittent sports is scarce. The aim of this study was to investi...

This study aimed to analyze the effect of an experimental operative high-intensity interval training (HIIT) program on the psychophysiological response of soldiers in a close quarter combat intervention. The psychophysiological response of twenty-two professional soldiers in a close quarter combat before and after an experimental 2- week operative...

Background Groin injuries are some of the most common injuries tennis players suffer. Several factors (e.g., post-match decrease in hip adductor (ADD) strength) have been proposed as possible mechanisms for increasing the incidence of this type of injury. However, the risk factors of developing groin injuries after a tennis match have not yet been...

Abstract Introduction: The study of chronic and acute responses when exposed to extreme, aggressive and stressful environments such as combat are becoming increasingly popular, since this information is leading to better optimization of soldiers physical and psychological performance as well as mission effectiveness and efficiency. Due to the inter...

Shoulder pain has been associated with glenohumeral internal rotation deficit (GIRD) and a reduction in external rotation (ER) strength; however, in tennis players, there is scarce evidence regarding the impact of a single match on shoulder range of motion (ROM), strength and serve speed. The aim of this study was to determine the acute effect of a...

Shoulder ROM and isometric strength comparison between pre- vs post-match (N = 26). (DOCX)

Tennis match analysis data. (DOCX)

Introduction: Volume and intensity are major variables governing exercise training–mediated beneficial effects in both athletes and patients. Although polarized endurance training optimizes and maximizes physiological gains in highly trained individuals, its cardiometabolic protective-effects have not been established. The purpose of the present si...

Objective: There is a growing tendency for physicians to prescribe exercise in accordance with the 'exercise is medicine' global health initiative. However, the exercise-pharmacologic interactions for controlling blood pressure are not well described. Our purpose was to study whether angiotensin II receptor type 1 blocker (ARB) antihypertensive me...

BACKGROUND: To explore the physical and physiological activity demands of talent soccer referees which belong to the Spanish Referees Technical Committee (CTA-RFFM) in order to understand the need of physical training and prescribe the most adequate exercise. METHODS: Fourteen semi-professional referees (25.8±3.8 years old; 1.79±0.03 m; 74.4±2.3 kg...

The authors determined the effect of high-intensity aerobic interval training on arterial stiffness and microvascular dysfunction in patients with metabolic syndrome with hypertension. Applanation tonometry was used to measure arterial stiffness and laser Doppler flowmetry to assess microvascular dysfunction before and after 6 months of stationary...

PurposeThe aim of this study was to determine the effects of high-intensity aerobic interval training (AIT) on exercise hemodynamics in metabolic syndrome (MetS) volunteers. Methods Thirty-eight, MetS participants were randomly assigned to a training (TRAIN) or to a non-training control (CONT) group. TRAIN consisted of stationary interval cycling a...

Aerobic interval training (AIT) improves the health of metabolic syndrome patients (MetS) more than moderate intensity continuous training. However, AIT has not been shown to reverse all metabolic syndrome risk factors, possibly due to the limited duration of the training programs. To assess the effects of 6 months of AIT on cardio-metabolic health...

http://www.fisiologiadelejercicio.com/libro-blog-2016_/ActualizacionesFE_2016.pdf

Purpose The purpose of this study was to determine, i) the reliability of blood lactate and ventilatory-based thresholds, ii) the lactate threshold that corresponds with each ventilatory threshold (VT1 and VT2) and with maximal lactate steady state test (MLSS) as a proxy of cycling performance. Methods Fourteen aerobically-trained male cyclists (V...

Objective: We studied the effects of exercise training alone or combined with dietary supplementation of omega-3 polyunsaturated fatty acids (Ω-3PUFA) and oleate on metabolic syndrome (MSyn) components and other markers of cardiometabolic health. Methods: Thirty-six patients with MSyn underwent 24 weeks of high-intensity interval training. In a...

This study explored the effects of physical activity (PA) and ambient temperature on water turnover and hydration status. Five-hundred seventy three healthy men and women (aged 20-60 years) from Spain, Greece and Germany self-reported PA, registered all food and beverage intake, and collected 24-h urine during seven consecutive days. Fasting blood...

Hydration status is linked with health, wellness, and performance. We evaluated hydration status, water intake, and urine output for seven consecutive days in healthy adults. Volunteers living in Spain, Germany, or Greece (n = 573, 39 ± 12 years (51.1% males), 25.0 ± 4.6 kg/m2 BMI) participated in an eight-day study protocol. Total water intake was...

http://www.fisiologiadelejercicio.com/wp-content/uploads/2016/03/ActualizacionesFE_2015.pdf

Our purpose in this study was to investigate efficient and sustainable combinations of exercise and diet-induced weight loss (DIET), in order to combat obesity in metabolic syndrome (MetS) patients. We examined the impact of aerobic interval training (AIT), followed by or concurrent to a DIET on MetS components. 36 MetS patients (54±9 years old; 33...

This study analyzed the effects of pseudoephedrine (PSE) provided at different time of day on neuromuscular performance, side effects, and violation of the current doping cut-off threshold [World Anti-Doping Agency (WADA)]. Nine resistance-trained males carried out bench press and full squat exercises against four incremental loads (25%, 50%, 75%,...

Purpose: To determine if muscle water content (H2Omuscle) expands with training in deconditioned middle-age men and the effects of this expansion in other muscle metabolites. Methods: Eighteen obese (BMI = 33±3 kg·m) untrained (VO2peak = 29±7 mL·kg·min) metabolic syndrome men completed a 4-month aerobic cycling training program. Vastus lateralis...

Hydration status is linked with health, wellness, and performance. We evaluated hydration status, water intake, and urine output for seven consecutive days in healthy adults. Volunteers living in Spain, Germany, or Greece (n = 573, 39 ± 12 years (51.1% males), 25.0 ± 4.6 kg/m² BMI) participated in an eight-day study protocol. Total water intake was...

Introduction: Hydration status is linked with health, wellness and performance; consequently it is of public health interest to evalua-te hydration status of population groups. Objectives: To evaluate hydration status and water intake and output for 7 consecutive days in healthy adults in summer and winter. Method / Design: Volunteers living in Spa...

Introduction: Daily water turnover depends on climate, body size and composition, fluid ingestion and physical activity among other factors. It is unclear if hydration status in individuals with high levels of physical activity (PA) is compromised due to higher water losses (respiratory, sweating) or is maintained by increased fluid ingestion. Obje...

Introduction: Hydration status is linked with total water intake from food and beverages, but also individual water requirements. It is unclear if drinking behaviour and knowledge influences hydration status in population groups. Objectives: To explore the association between drinking knowledge and hydration status based on total water intake (TWI)...

Over the last years, the interest of ergogenic aids has grown in the competitive sports arena. As a result, supplementation companies have found a new market and have created an array of products targeting competitive athletes. However, only a few legal supplements have been recognized by scientific literature as being able to enhance performance....

We determined if dehydration alone or in combination with hyperthermia accelerates muscle glycogen use during intense exercise. Seven endurance-trained cyclists (VO2max = 54.4 ± 1.05 mL/kg/min) dehydrated 4.6% of body mass (BM) during exercise in the heat (150 min at 33 ± 1 °C, 25 ± 2% humidity). During recovery (4 h), subjects remained dehydrated...

IN RECENT YEARS, THE INTEREST OF ERGOGENIC AIDS HAS GROWN IN THE COMPETITIVE SPORTS ARENA. AS A RESULT, SUPPLEMENTATION COMPANIES HAVE FOUND A NEW MARKET AND HAVE CREATED AN ARRAY OF PRODUCTS TARGETING COMPETITIVE ATHLETES. HOWEVER, ONLY A FEW LEGAL SUPPLEMENTS HAVE BEEN RECOGNIZED BY SCIENTIFIC LITERATURE AS BEING ABLE TO ENHANCE PERFORMANCE. THES...

It is usually stated that glycogen is stored in human muscle bound to water in a proportion of 1:3 g. We investigated this proportion in biopsy samples during recovery from prolonged exercise. On two occasions, nine aerobically trained subjects ([Formula: see text] = 54.4 ± 1.05 mL kg(-1) min(-1); mean ± SD) dehydrated 4.6 ± 0.2 % by cycling 150 mi...

This study investigated which exercise mode (continuous or sprint interval) is more effective for improving insulin sensitivity. Ten young, healthy men underwent a non-exercise trial (CON) and 3 exercise trials in a cross-over, randomized design that included 1 sprint interval exercise trial (SIE; 4 all-out 30-s sprints) and 2 continuous exercise t...

We studied if dehydrating exercise would reduce muscle water (H2Omuscle) and affect muscle electrolyte concentrations. Vastus lateralis muscle biopsies were collected prior, immediately after, and 1 and 4 h after prolonged dehydrating exercise (150 min at 33 ± 1 °C, 25% ± 2% humidity) on nine endurance-trained cyclists (VO2max = 54.4 ± 1.05 mL/kg/m...

Background and Aims Exercise training can improve health of patients with metabolic syndrome (MetS). However, which MetS factors are most responsive to exercise training remains unclear. We studied the time-course of changes in MetS factors in response to training and detraining. Methods and Results Forty eight MetS patients (52±8.8 yrs old; 33±4...

Caffeine is an ergogenic aid widely used prior to and during prolonged exercise. Due to its prolonged biological half-life caffeine effects could remain after exercise. We aimed to investigate the metabolic, respiratory and cardiovascular post-exercise responses to pre-exercise graded caffeine ingestion. Twelve aerobically trained subjects (mean VO...

To determine whether the ergogenic effects of caffeine ingestion on neuromuscular performance are similar when ingestion takes place in the morning and in the afternoon. Double blind, cross-over, randomized, placebo controlled design. Thirteen resistance-trained males carried out bench press and full squat exercises against four incremental loads (...

In Olympic combat sports, weight cutting is a common practice aimed to take advantage of competing in weight divisions below the athlete's normal weight. Fluid and food restriction in combination with dehydration (sauna and/or exercise induced profuse sweating) are common weight cut methods. However, the resultant hypohydration could adversely affe...

Combining metformin and exercise is recommended for the treatment of insulin resistance. However, it has been suggested that metformin blunts the insulin-sensitizing effects of exercise. We evaluated in a group of insulin-resistant patients the interactions between exercise and their daily dose of metformin. Ten insulin-resistant patients underwent...

The aim of the present study was to determine which of the available glucose tolerance tests (oral (OGTT) vs. intravenous (IVGTT)) could more readily detect the insulin sensitizing effects of a bout of continuous exercise. Ten healthy moderately fit young men (V̇O2peak of 45.4 ± 1.8 mL·kg⁻¹·min⁻¹; age 27.5 ± 2.7 yr) underwent 4 OGTT and 4 IVGTT on...

The aim of this study was to determine the effect of time-of-day on sprint swimming performance and on upper and lower body, maximum strength, and muscle power. Twelve well-trained junior swimmers (six male and six female) were tested for bench press (BP) maximum strength and muscle power, jump height countermovement vertical jump (CMJ), crank-arm...

Purpose: The purpose of this study was to determine the oral dose of caffeine needed to increase muscle force and power output during all-out single multijoint movements. Methods: Thirteen resistance-trained men underwent a battery of muscle strength and power tests in a randomized, double-blind, crossover design, under four different conditions...

We studied if salt and water ingestion alleviates the physiological strain caused by dehydrating exercise in the heat. Ten trained male cyclists ( V ˙ O 2 m ⁢ a x  : 60 ± 7 mL/kg/min) completed three randomized trials in a hot-dry environment (33 °C, 30% rh, 2.5 m/s airflow). Ninety minutes before the exercise, participants ingested 10 mL of water/...

A high saturated fatty acids diet (HSFAD) deteriorates metabolic and cardiovascular health while aerobic training improves them. The aim of this study was to investigate in physically inactive and overweight people if 2 weeks of HSFAD leads to hyperlipemia or insulin resistance and if concurrent aerobic exercise training counteracts those effects....

To investigate whether caffeine ingestion counteracts the morning reduction in neuromuscular performance associated with the circadian rhythm pattern. Twelve highly resistance-trained men underwent a battery of neuromuscular tests under three different conditions; i) morning (10:00 a.m.) with caffeine ingestion (i.e., 3 mg kg(-1); AM(CAFF) trial);...

To investigate the effects of a caffeine-containing energy drink on soccer performance during a simulated game. A second purpose was to assess the post-exercise urine caffeine concentration derived from the energy drink intake. Nineteen semiprofessional soccer players ingested 630 ± 52 mL of a commercially available energy drink (sugar-free Red Bul...

The aim of this study was to investigate the relevance of individual characteristics for thermoregulation during prolonged cycling in the heat. For this purpose, 28 subjects cycled for 60 min at 60% VO(2peak) in a hot-dry environment (36 ± 1°C; 25 ± 2% relative humidity, airflow 2.5 m/s). Subjects had a wide range of body mass (99-43 kg), body surf...