Athanasios Chatzinikolaou

• PhD
• Professor (Associate) at Democritus University of Thrace

Background/Objectives: Master athletes in team sports represent a growing population of individuals who continue to engage in structured training and competition. Among these sports, basketball has primarily been investigated in older athletes; however, age-related effects on training load within the broader master athlete population remain largely...

Introduction: Warm-up is essential for optimizing athletic performance in both individual and team sports, though its effects tend to diminish or disappear after a certain period of time. However, in soccer, competition rules mandate a 15-min transition period before the match begins. Purpose: This study investigated the effect of this transitional...

Background/Objectives: The purpose of the study was to investigate the effects of a priming training session with either a light or heavy load snatch and clean pulls on weightlifting performance. Methods: Twelve well-trained weightlifters (seven males and five females) participated in the study. The athletes followed a counterbalanced study design...

Background/objectives: Despite being widely promoted, protein supplementation's overall effectiveness during demanding basketball schedules remains unclear. This study investigated whether increased protein intake can accelerate recovery of muscle function during a 6-day congested basketball microcycle consisting of three consecutive games while a...

This case study aimed to evaluate the body composition and several biochemical markers during a 7-month pre-competition training period of a natural male bodybuilder. The athlete monitored his nutrition, training variables, and daily physical activity during the preparation phase. At the beginning (W31), in the middle (W18), and one week before the...

Citation: Ispirlidis, I.; Pantazis, D.; Poulios, A.; Avloniti, A.; Stampoulis, T.; Michailidis, Y.; Troupkos, K.; Evangelou, E.; Draganidis, D.; Balampanos, D.; et al. The Effect of Intraset Rest Periods on External and Internal Load During Small-Sided Games in Soccer. Sports 2024, 12, 331. Abstract: The purpose of this study was to compare the int...

Background Soccer is linked to an acute inflammatory response and the release of reactive oxygen species (ROS). Antioxidant supplements have shown promising effects in reducing muscle damage and oxidative stress and enhancing the recovery process after eccentric exercise. This critical review highlights the influence of antioxidant supplements on p...

Maturation is a key factor in sports participation and often determines the young athletes’ characterization as a talent. However, there is no evidence of practical models for understanding the factors that discriminate children according to maturity. Hence, this study aims to deepen the understanding of the factors that affect maturity in 11-year-...

This study aimed to monitor the oxygenation and blood supply in three quadriceps muscles [the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF)] during squatting exercise to exhaustion. Eighteen young resistance-trained males performed five sets of 15 back squats in a Smith machine, with two warm-up sets [at 14% and 45% of the 15...

Poulios, A, Fotiou, C, Draganidis, D, Avloniti, A, Rosvoglou, A, Batrakoulis, A, Tsimeas, P, Papanikolaou, K, Deli, CK, Stampoulis, T, Douroudos, II, Chatzinikolaou, A, Jamurtas, AZ, and Fatouros, IG. The energy expenditure associated with body-weight resistance exercises of various movement patterns performed at different durations. J Strength Con...

This study aimed to investigate the effect of a mixed intervention program, with live and distance online Tai Chi (TC) practice on healthy adult practitioners and its effect on dynamic balance, physical function of lower limbs and aerobic capacity, which were measured at baseline and follow up. The sample of the study consisted of the experimental...

This study aimed to investigate the effect of a mixed intervention program, with live and distance online Tai Chi (TC) practice on healthy adult practitioners and its effect on dynamic balance, physical function of lower limbs and aerobic capacity, which were measured at baseline and follow up. The sample of the study consisted of the experimental...

Purpose To examine the recovery kinetics (i.e. time-dependent changes) of performance-related variables between two 120-min male football games performed three days apart with and without carbohydrate (CHO) supplementation. Methods 20 male players (20 ± 1 years; body fat: 14.9 ± 5.1%; VO 2max : 59.4 ± 3.7 mL•kg ⁻¹ •min ⁻¹ ) participated in two 120...

Σκοπός της μελέτης ήταν η επίδραση ενός προγράμματος Τάι Τσι (ΤΤ), με ζωντανή και εξ αποστάσεως σύγχρονης διαδικτυακής άσκησης σε υγιείς ενήλικες στους δείκτες υγείας στην ποιότητα ζωής. Το δείγμα της μελέτης αποτέλεσαν η πειραματική ομάδα ΤΤ 19 υγιών ατόμων, χωρισμένη σε δύο υποομάδες (αρχάριοι και έμπειροι). 15 υγιή μη κινητικά δραστήρια άτομα απ...

In modern coaching power improvement in sport performance is recommended to be pursue through the competing movement, by using various forms of resistance such as external loads (ankle weights). However, extra resistance is not beneficial if it greatly changes kicking technique. The purpose of the present study was to examine the effect of external...

Athletes who suffered severe negative effects from the COVID-19 pandemic were forced to change habits and significant restrictions were placed upon the exercise of their profession. The main purpose of this research is to investigate the psychological effects of athletes during the COVID-19 pandemic, by assessing the levels of fear of the disease...

The purpose of this study was to examine the effect of a mixed intervention program with live and online Tai Chi practice on the sleep quality of the participants. The sample of the research consisted of 19 practitioners (7 men & 12 women), with an average age of 53.9 ± 6.3 years. They participated in an organized Tai Chi Chuan program which lasted...

It is a fact that biological maturity significantly affects the performance of football players at the age of 12-14 years old due to the many and intense physical changes, and the phenomenon of "adolescent awkwardness". The purpose of the present study was to examine the effect of biological maturity on the physical performance of young soccer play...

It is a fact that children who are in the phase of peak height velocity may show "adolescent awkwardness", which is expressed by a decrease in reactive strength and the ability to perform sprints. However, the results are controversial for children who regularly participate in the sports such as football. The purpose of this study was to examine t...

This study examined the effects of an alternative strength training method during soccer training on the development of physical and technical abilities of youth soccer players. 17 soccer players (age: 15 ±0.5 years) were divided in a control group (CG) and an experimental group (EG). The players of the EG wore a "weight shorts", with 300 gr of add...

Aging is associated with the development of chronic low-grade systemic inflammation (LGSI) characterized by increased circulating levels of proinflammatory cytokines and acute phase proteins such as C-reactive protein (CRP). Collective evidence suggests that elevated levels of inflammatory mediators such as CRP, interleukin-6 (IL-6), and tumor necr...

Tai Chi is a Chinese martial art that strengthens, stretches and balances the practitioner. It can be considered one of the best forms of exercise to improve balance and avoid falls in adults. The implementation of distance learning due to the pandemic has been a solution for many exercise programs. The purpose of this study was to investigate the...

It is well-documented that chronic/regular exercise improves the cardiovascular function, decreases oxidative stress and enhances the antioxidant capacity in coronary artery disease (CAD) patients. However, there is insufficient evidence regarding the chronic effects of different types of training and detraining on cardiovascular function and the l...

Background Soccer-specific speed-endurance training induces short-term neuromuscular fatigue and performance deterioration over a 72-h recovery period, associated with elevated markers of exercise-induced muscle damage. We compared the effects of whey vs. soy protein supplementation on field activity, performance, muscle damage and redox responses...

Problem statement: Pre-warm-up actions have gained popularity in soccer in recent years but their effectiveness has not been sufficiently researched. Purpose: The aim of this study was to investigate the effect of a pre-warm-up exercise program, with emphasis on muscular activation and neuromuscular control, on selected performance and injury-relat...

Backround: New training methods are constantly used to improve the ability of skeletal muscles to develop strength. Objective: The aim of the present study was to investigate the effect of half-squat training with free weights and flywheel device on isokinetic knee muscle strength for well-trained amateur soccer players. Methods: Forty eight p...

Background: The aim of this study is to compare the effects of semi-squat exercise with a flywheel device and free weights on parameters of physical performance. Methods: 48 well-trained male athletes were randomly divided into three subject groups (n = 16 each), two training groups (DT and RT) and one control group (CON). The duration of the in...

The objective of this study was to identify the most important health/fitness trends while examining the impact of various demographics of respondents on the top trends for the first time in Greece. An online survey was sent to 3,487 professionals who worked in the health/fitness sector using the methodology of similar regional and worldwide studie...

[This corrects the article DOI: 10.1371/journal.pone.0202390.].

Batzakas Komninos: Bone status comparisons between dominant and nondominant leg in soccer players (Under the supervision of Assistant Professor Mrs. A. Avloniti) Football is characterized as a particularly osteogenic sport, but also as a sport that creates imbalances in the two lower limbs, due to their unbalanced use. Τhe purpose of this study was...

This study investigated the effects of a 10-month high-intensity interval-type neuromuscular training programme on musculoskeletal fitness in overweight and obese women. Forty-nine inactive females (36.4 ± 4.4 yrs) were randomly assigned to either a control (N = 21), a training (N = 14, 10 months) or a training-detraining group (N = 14, 5 months tr...

It is unclear how high-intensity, interval-type nontraditional exercise training programs can be feasible and effective options for inactive obese individuals in a real-world gym setting. This randomized controlled trial investigated the hypothesis that a 10-month high-intensity, group interval-type neuromuscular training program (DoIT) with adjunc...

Redox status (RS) perturbations and inflammation are fundamental features of chronic kidney disease (CKD) that are substantially exacerbated in end-stage renal disease (ESRD). This study aimed at investigating the efficacy of a 6-month intradialytic exercise training program on RS, inflammation and physical performance in patients with ESRD. Twenty...

INTRODUCTION: Obesity is systematically growing at an alarming rate worldwide and inactive individuals with obesity are likely to exhibit raised reactive oxygen species and/or reduced antioxidant capacity elevating oxidative stress that promotes physiological dysfunction. On the other hand, high-intensity interval training (HIIT), small group train...

Football is a sport characterized by numerous jumps, direction of changes and transitions between acceleration and deceleration phases. Due to the gravitational forces developed in these movements, football is considered an osteogenic sport. The study aimed at comparing football’s effect in bone mineral density and content (BMD, BMC) between the d...

Obesity epidemic is a complex and multifactorial chronic condition affecting one in three adults globally while it is associated with high metabolic risk factors enhancing chronic illness. On the other hand, high-intensity interval training (HIIT), group training, body weight training, and functional fitness training have been recently reported as s...

Purpose: To examine the recovery kinetics of exercise-induced muscle damage (EIMD), neuromuscular fatigue, and performance following small-sided games (SSGs) of different densities in soccer. Methods: Ten male players randomly completed 3 trials: a control trial (no SSGs), 4v4 SSGs (62.5 m2/player), and 8v8 SSGs (284.4 m2/player). External and i...

Purpose: To determine the recovery kinetics of performance, muscle damage, and neuromuscular fatigue following 2 speed-endurance production training (SEPT) protocols in soccer. Methods: Ten well-trained, male soccer athletes randomly completed 3 trials: work-to-rest ratio (SEPT) 1:5, SEPT/1:8, and a control trial. Training load during SEPT was m...

Purpose To investigate the association of the hypothalamic-pituitary-testicular (HPT) axis with pro- and anti- oxidation, in relation to puberty and obesity in boys, before and after an aerobic exercise bout. Methods This is a cross-sectional human observational study of 92 healthy normal-weight, obese pre- and early- pubertal boys that underwent...

Protein supplementation is a major nutritional practice among professional and amateur team-sport athletes representing a market of $5 billion in the USA alone. This practice, however, may not be supported by evidence-based science. Our objective as to present a thorough review of literature investigating the effects of protein supplementation on p...

Background: Muscle satellite cells (SCs) are crucial for muscle regeneration following muscle trauma. Acute skeletal muscle damage results in inflammation and the production of reactive oxygen species (ROS) which may be implicated in SCs activation. Protection of these cells from oxidative damage is essential to ensure sufficient muscle regenerati...

INTRODUCTION: Sedentary obese adults demonstrate impaired functional capacity while the obesity epidemic is expanding at an alarming rate worldwide. On the other hand, high-intensity interval training (HIIT), small group training, and functional fitness are currently the most prevalent trends in the global fitness industry. PURPOSE: This randomized...

The purpose of this study was to evaluate the reliability and reproducibility of the physiological and overload features of the Yo-Yo intermittent endurance test level 2 (Yo-Yo IE2) in competitive male soccer (n = 20), basketball (n = 11), and volleyball players (n = 10). The participants completed Yo-Yo IE2 tests on three separate occasions with a...

Background Muscle satellite cells (SCs) are crucial for muscle regeneration following muscle trauma. Acute skeletal muscle damage results in inflammation and production of reactive oxygen species (ROS) which may be implicated in SCs activation. Protection of these cells from oxidative damage is essential to ensure sufficient muscle regeneration. Th...

Background Muscle satellite cells (SCs) are crucial for muscle regeneration following muscle trauma. Acute skeletal muscle damage results in inflammation and production of reactive oxygen species (ROS) which may be implicated in SCs activation. Protection of these cells from oxidative damage is essential to ensure sufficient muscle regeneration. Th...

Obesity is associated with high mortality and morbidity rates and low levels of quality of life among adults globally. It is critical to examine evidence-based practices for developing lifestyle behavioral changes such as physical movement and structured exercise training. The DoIT protocol, a high-intensity interval exercise training (HIIT) progra...

Background Muscle satellite cells (SCs) are crucial for muscle regeneration following muscle trauma. Acute skeletal muscle damage results in inflammation and production of reactive oxygen species (ROS) which may be implicated in SCs activation. Protection of these cells from oxidative damage is essential to ensure sufficient muscle regeneration. Th...

Η χρήση της μουσικής κατά τη διάρκεια προπονήσεων είναι ένα συχνό φαινόμενο. Σκοπός της έρευνας ήταν να εξετάσει την επίδραση του «δυνατότερου» περιεχομένου ενός αυτο-επιλεγόμενου μουσικού κομματιού στην απόδοση της μέγιστης ισομετρικής συστολής των εκτεινόντων μυών του γόνατος. Δεκατέσσερις υγιείς φοιτητές της Σ.Ε.Φ.Α.Α.-Δ.Π.Θ., πραγματοποίησαν μέ...

Background: Muscle satellite cells (SCs) are crucial for muscle regeneration following muscle trauma. Acute skeletal muscle damage results in inflammation and production of reactive oxygen species (ROS) which may be implicated in SCs activation. Protection of these cells from oxidative damage is essential to ensure sufficient muscle regeneration. T...

Panagoulis, C, Chatzinikolaou, A, Avloniti, A, Leontsini, D, Deli, CK, Draganidis, D, Stampoulis, T, Oikonomou, T, Papanikolaou, K, Rafailakis, L, Kambas, A, Jamurtas, AZ, and Fatouros, IG. In-season integrative neuromuscular strength training improves performance of early-adolescent soccer athletes. J Strength Cond Res XX(X): 000-000, 2018-Althoug...

AIM: Body weight training, high-intensity interval training (HIIT), functional fitness, group personal training, and circuit training are currently considered as some of the top worldwide trends in the health and fitness industry. This randomized controlled trial examined the effects of a circuit-like functional high-intensity training program on f...

serial number: 691 Poster Number: P1-P210 Introduction: Puberty is a maturation period characterized by changes of the dynamically regulated HPG axis. Obesity in childhood and especially after the onset of puberty is a relatively hypogonadal state. Oxidative stress is a state of imbalance between pro-and anti-oxidation within the cell. Pro-oxidatio...

This randomized controlled trial examined body mass, body composition, energy balance and performance responses of previously sedentary overweight/obese women to a circuit-type integrated neuromuscular training program with alternative modalities. Forty-nine healthy overweight or class I obese females (36.4±4.4 yrs) were randomly assigned to either...

Study protocol in Greek. (PDF)

CONSORT 2010 checklist. (PDF)

A single bout of exercise can result in inflammatory responses, increased oxidative stress and upregulation of enzymatic antioxidant mechanisms. Although low-volume high-intensity interval training (HIIT) has become popular, its acute responses on the above mechanisms have not been adequately studied. The present study evaluated the effects of HIIT...

The effects of protein supplementation on performance recovery and inflammatory responses during a simulated one-week in-season microcycle with two games (G1, G2) performed three days apart were examined. Twenty football players participated in two trials, receiving either milk protein concentrate (1.15 and 0.26 g/kg on game and training days, resp...

Purpose: Τo investigate the effect of a complex, short-term strength/power training protocol on performance and body composition of elite early-adolescent soccer players. Methods: Twenty-two players (14-15 years) were randomly assigned to (a) an experimental (EG, n=12, participated in a 5-week training protocol with traditional multi-joint power...

ΣΚΟΠΟΣ: Η δίκυκλη αστυνόμευση είναι απαιτητική όχι μόνο λόγω της φύσης του επαγγέλματος του αστυνομικού, αλλά και λόγω της υποχρέωσης για ασφαλή και γρήγορη οδήγηση, που μπορεί να είναι συνεχόμενη καθ’ όλο το ωράριο εργασίας ή με τακτικές στάσεις με ανάβαση και κατάβαση από τη μηχανή. Σκοπός της παρούσας μελέτης ήταν να καταγράψει το προφίλ φυσικής...

The ubiquitin–proteasome system (UPS) is the main cellular proteolytic system responsible for the degradation of normal and abnormal (e.g. oxidised) proteins. Under catabolic conditions characterised by chronic inflammation, the UPS is activated resulting in proteolysis, muscle wasting and impaired muscle function. Milk proteins provide sulphur-con...

Context Although there is increasing information on the mechanism of lipolysis in adipose tissue, the effect of exercise on individual factors of lipolysis is less well understood. Objective We aimed to compare changes in adipose tissue triacylglycerol lipase activity and gene expression of adipose triacylglycerol lipase (ATGL), hormone sensitive...

The body weight training, high-intensity interval training (HIIT), functional fitness, group personal training, and circuit training are currently some of the top worldwide trends in the commercial, corporate, clinical, and community landscapes within the health and fitness industry. Additionally, adult obesity and physical inactivity are considere...

Major objectives of army and navy training are the development of readiness, performance, and injury prevention. Numerous studies have examined the effect of specific strength training programs (ST) on performance of Special Forces and military personnel. Although navy personnel have to address on board conditions that require the development of st...

The body weight training, high-intensity interval training (HIIT), functional fitness, group personal training, and circuit training are currently some of the top worldwide trends in the commercial, corporate, clinical, and community landscapes within the health and fitness industry. Additionally, adult obesity and physical inactivity are considere...

Purpose: Presumed interrelationships among deleterious aspects of adipose tissue metabolism, inflammation, and cellular oxidative stress could be influenced by pubertal hormonal changes. They were investigated in pre- and early pubertal normal-weight and obese boys before and after an exercise bout employed as an energy demanding stimulator. Meth...

The purpose of the study was to examine the effect of creatine (Cr) supplementation on anaerobic performance when ingesting creatine and carbohydrates (CHO) together. Twenty male physical education students comprised the two experimental (CR and CRCHO) and one control (CON) groups of the study. All groups performed three 30 s anaerobic Wingate test...

Adults demonstrate an upregulation of their pro- and anti-oxidant mechanisms in response to acute exercise while systematic exercise training enhances their antioxidant capacity, thereby leading to a reduced generation of free radicals both at rest and in response to exercise stress. However, less information exists regarding oxidative stress respo...

High-intensity interval training (HIIT), functional fitness and circuit training are included in the top trends of the health and fitness industry while adult obesity and physical inactivity rates have grown immensely worldwide. PURPOSE: This study examined the effectiveness of a time-effective, functional integral HIIT program to improve body comp...

We used thiol-based antioxidant supplementation (n-acetylcysteine, NAC) to determine whether immune mobilisation following skeletal muscle microtrauma induced by exercise is redox-sensitive in healthy humans. According to a two-trial, double-blind, crossover, repeated measures design, 10 young men received either placebo or NAC (20 mg/kg/day) immed...

This study investigated the effects of different levels of habitual physical activity (PA) assessed by pedometry on bone turnover markers of preadolescent girls according to a cross-sectional experimental design. Sixty prepubertal girls of similar chronological age, bone age, maturity level, and nutritional status were assigned to a low PA (LPA; n...

Inflammaging is the chronic low-grade inflammatory state present in the elderly, characterized by increased systemic concentrations of proinflammatory cytokines. It has been shown that inflammaging increases the risk of pathologic conditions and age-related diseases, and that it also has been associated with increased skeletal muscle wasting, stren...

High-intensity interval training (HIIT), functional fitness and circuit training are included in the top trends of the health and fitness industry while adult obesity and physical inactivity rates have grown immensely worldwide. PURPOSE: This study examined the effectiveness of a time-effective, functional integral HIIT program to improve body comp...

Στη διεθνή βιβλιογραφία είναι τεκμηριωμένο πως ένας αγώνας καλαθοσφαίρισης μπορεί να προκαλέσει τη μείωση στην παραγωγή δύναμης έως και 48 ώρες μετά τη διεξαγωγή του. Το γεγονός αυτό περιορίζει τη δυνατότητα των αθλητών να συμμετάσχουν σε προπονητικές μονάδες με υψηλή ένταση. Αν και στην προπόνηση πραγματοποιούνται περιεχόμενα με τα ίδια κινητικά π...

Purpose: We examined effects of a three-game, 1-week microcycle (G1, G2, G3) on recovery of performance and inflammatory responses in professional male footballers. Methods: Players were randomized into an experimental (EXP; N = 20) and a control group (CON; N = 20). Blood was drawn and repeated sprint ability (RSA), muscle soreness and knee ran...

Background: Pre-school age is important for developing healthy attitudes towards physical activity (PA). However, research on pre-schoolers' pedometer-determined PA is limited. Aim: To describe pre-schoolers' ambulatory activity; investigate step count differences in respect to Body Mass Index (BMI) categories and examine the prevalence of obesi...

We examined the temporal variation of iron's status markers during a 60 h period following a football game. Thirty-four male football players were randomly assigned to a control group (CG, N = 14, participated only in measurements and training) or an experimental group (EG, N = 20, took part in a football game one week after the completion of the c...

Introduction Delayed-onset muscle soreness (DOMS) has been defined as a form of muscular hyperalgesia and manifests as pain and stiffness in the muscles several hours after strenuous or unaccustomed exercise (Clarkson et al., 1992). Multiple methods exist to assess the perceived soreness, however there are some limitations such as the standardizati...