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1.
Healthcare (Basel) ; 12(2)2024 Jan 16.
Article in English | MEDLINE | ID: mdl-38255107

ABSTRACT

As the population ages, maintaining an active lifestyle becomes increasingly vital to promote overall health and well-being in older individuals. Water- and land-based exercises have emerged as popular options, each offering a distinct set of benefits tailored to the unique needs of this population group. An electronic database search, including PubMed, Scopus, MEDLINE, and Web of Science, was conducted until 15 September 2023, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, to investigate the effects of water-based compared to land-based exercise on selected fitness parameters in older healthy individuals. The eligibility criteria included studies with at least two groups of participants aged 60 and older, with physical fitness outcome measures. A total of ten studies met the inclusion criteria and were analyzed. While both exercise modalities may offer significant benefits, this review's findings emphasized the absence of conclusive evidence and consensus for recommending a single exercise category applicable to aquatic or land environments and providing more definite guidance to improve health-related physical fitness parameters in healthy older individuals. Finally, combining both training approaches may lead to a comprehensive array of health benefits for this age group population by also considering individual's needs, preferences, and fitness goals.

2.
Biomedicines ; 11(9)2023 Sep 07.
Article in English | MEDLINE | ID: mdl-37760929

ABSTRACT

Mitochondria play a vital role in maintaining cellular energy homeostasis, regulating apoptosis, and controlling redox signaling. Dysfunction of mitochondria has been implicated in the pathogenesis of various brain diseases, including neurodegenerative disorders, stroke, and psychiatric illnesses. This review paper provides a comprehensive overview of the intricate relationship between mitochondria and brain disease, focusing on the underlying pathological mechanisms and exploring potential therapeutic opportunities. The review covers key topics such as mitochondrial DNA mutations, impaired oxidative phosphorylation, mitochondrial dynamics, calcium dysregulation, and reactive oxygen species generation in the context of brain disease. Additionally, it discusses emerging strategies targeting mitochondrial dysfunction, including mitochondrial protective agents, metabolic modulators, and gene therapy approaches. By critically analysing the existing literature and recent advancements, this review aims to enhance our understanding of the multifaceted role of mitochondria in brain disease and shed light on novel therapeutic interventions.

3.
Front Sports Act Living ; 5: 1229066, 2023.
Article in English | MEDLINE | ID: mdl-37533584

ABSTRACT

This study investigated swim coaches' perceptions of professional development issues and current training practices according to their coaching experience, education level, and gender. An online survey (January-April 2022) was completed by 123 swim coaches (96 male/27 female) of competitive swimmers based in 41 countries. The survey consisted of 36 questions divided into six sections: (1) background information, (2) developing swim coaching through learning, (3) self-evaluation, (4) interpersonal-intrapersonal interactions, (5) life skills, and (6) analyzing swimming performance. Pearson chi-square assessed the relationship between the frequency of responses and professional background and gender. The survey results indicated that swim coaches' educational level is potentially one of the most influential parameters affecting the coaches' perceptions about their own professional development. The data presented may be used for the future design of coach education programmes as they advance current knowledge on understanding psycho-social issues related to professional development and training perceptions involved in the competitive swimming environment.

4.
J Sports Med Phys Fitness ; 63(1): 212, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36519331

ABSTRACT

This article was published in Volume 62, issue 6 of publishing year 2022, with a mistake in Table II. The correct Table II is the one included in this erratum.

5.
J Strength Cond Res ; 36(12): 3440-3445, 2022 Dec 01.
Article in English | MEDLINE | ID: mdl-36417358

ABSTRACT

ABSTRACT: Asimakidis, ND, Dalamitros, AA, Ribeiro, J, Lola, AC, and Manou, V. Μaturation stage does not affect change of direction asymmetries in young soccer players. J Strength Cond Res 36(12): 3440-3445, 2022-This study examined whether the stage of biological maturation can affect interlimb asymmetries during a change of direction (COD) test. Seventy-six young soccer players were divided into 2 different groups according to their peak height velocity stage (PHV): pre-PHV (n = 45, age = 11.8 ± 1.2 years, height = 149.8 ± 9.3 cm, body mass = 43.9 ± 11.2 kg) and post-PHV (n = 31, age = 14.4 ± 0.9 years, height = 170.0 ± 4.9 cm, body mass = 61.5 ± 8.9 kg). Subjects performed a 505 test to measure the completion time in both directions and a 20-m maximum sprint test. Change of direction deficit (CODD) was used as a measure for isolating COD ability. An independent sample t-test detected no significant differences between the asymmetry index values for the 505 test completion time when the pre-PHV group and the post-PHV group were compared (-3.49 ± 2.49% vs. -3.45 ± 2.47%, effect size [ES] = 0.02, p = 0.923). Similarly, the CODD asymmetry index indicated no differences between the 2 groups (-8.21 ± 5.95% vs. -7.37 ± 5.12%, ES = 0.15, p = 0.457). A paired sample t-test revealed that the values of the CODD asymmetry index were larger than those of the 505 asymmetry index (-7.88 ± 5.61% vs. -3.49 ± 2.46%, ES = 1.09, p < 0.001). According to these results, maturational status has no influence on the interlimb asymmetries of COD ability. Furthermore, subjects showed greater asymmetry values in CODD compared with the 505 test completion time, reinforcing that the evaluation of COD asymmetries should be based on CODD. As interlimb asymmetries are not altered during the maturation process, practitioners should address abnormal COD asymmetries early on during athletes' development processes.


Subject(s)
Athletic Performance , Soccer , Humans , Child , Adolescent , Athletes , Body Height
6.
Article in English | MEDLINE | ID: mdl-35564333

ABSTRACT

The COVID-19 outbreak has led to an unprecedented long-term cessation in athletes' training routines. This study examined the effect of a 32-week detraining period, caused by the COVID-19 pandemic lockdown, on selected neuromuscular performance indicators in 29 young male soccer players, assessed close to their adolescent growth spurt (age = 13.0 ± 0.8 years). Change of direction ability of both lower limbs (COD), linear sprint times (10 and 20 m), and vertical jump height (CMJ) was evaluated twice, once before the first national lockdown, and one week after the return to training activities. Paired-sample t-tests detected significant improvements in all three testing variables (COD: 2.82 ± 0.23 vs. 2.66 ± 0.22 s, p ≤ 0.005, 0.001, effect size [ES] = 0.91 to 1.05 for the right and left limb, respectively; 10 m: 2.12 ± 0.16 vs. 1.96 ± 0.15 s, p ≤ 0.001, effect size [ES] = 1.67, 20 m: 3.56 ± 0.3 vs. 3.42 ± 0.27 s, p ≤ 0.001, effect size [ES] = 1.02 and CMJ: 23.3 ± 7.5 vs. 24.5 ± 7.6 cm, p = 0.033, ES = 0.42). These results indicate that maturation-related adaptations can lead to enhanced change of direction, linear sprint, and vertical jump performance, even in the absence of exposure to any level of exercise. Soccer coaches and practitioners working with youth athletes should consider the stage of maturation when planning and implementing training programs aiming to enhance neuromuscular performance.


Subject(s)
Athletic Performance , COVID-19 , Soccer , Adolescent , COVID-19/epidemiology , Child , Communicable Disease Control , Humans , Male , Pandemics
7.
J Sports Med Phys Fitness ; 62(6): 749-756, 2022 Jun.
Article in English | MEDLINE | ID: mdl-33768779

ABSTRACT

BACKGROUND: Young swimmers are rarely involved in training control, leading to inadequate volume and prescription of training intensities. This study aimed to examine the effect of prescribing and monitoring training intensities around critical velocity (CV) on 400 m front-crawl performance during an 8-weeks period. METHODS: Twenty young male swimmers (13.4±1.0 years) were randomly assigned into two groups. The experimental group (EG) used training monitoring based on intensities around CV (95, 100, 105 and 110% of CV), while for the control group (CG) different heart rate (HR) zones (EN1+, EN2, EN2+ and EN3) were used as an intensity criterion. The training volume was the same for both EG and CG. A maximal 400 m front-crawl test was performed before and after the 8-week period to determine CV intensities and to assess alternations in performance. The rate of perceived exertion (RPE) and HR values were also evaluated. RESULTS: Significant main effects of time were observed for T400, CV, HR and RPE. A significant group × time interaction was found for T400 (P=0.035, effect size = 1.07, moderate). Results revealed significant pre-to-postimprovements for both EG (from 328.46±26.25 to 305.88±20.09) and CG (from 329.07±25.24 to 314.75±19.87). A significant group × time interaction was also found for CV (P=0.005, effect size=1.51, large). Results revealed significant pre- to post improvements for both EG (from 1.126±0.08 to 1.207±0.07) and CG (from 1.124±0.08 to 1.173±0.07). CONCLUSIONS: Both training methods induced significant improvements in 400 m front-crawl performance with a greater degree for the training prescription and monitoring using CV intensities.


Subject(s)
Swimming , Humans , Male , Swimming/physiology
8.
Front Sports Act Living ; 3: 759925, 2021.
Article in English | MEDLINE | ID: mdl-34966893

ABSTRACT

This study aimed to determine the relationship between three testing procedures during different intensity interval efforts in swimming. Twelve national-level swimmers of both genders executed, on different occasions and after a standardized warm-up, a swimming protocol consisting of either a submaximal (Submax: 8 efforts of 50 m) or a maximal interval (Max: 4 efforts of 15 m), followed by two series of four maximal 25 m efforts. Near-infrared spectroscopy in terms of muscle oxygen saturation (SmO2), heart rate (HR), and blood lactate concentration (BLa) were analyzed at three testing points: after the Submax or the Max protocol (TP1), after the 1st 4 × 25-m (TP2), and after the 2nd maximal 4 × 25-m set (TP3). BLa and HR showed significant changes during all testing points in both protocols (P ≤ 0.01; ES range: 0.45-1.40). SmO2 was different only between TP1 and TP3 in both protocols (P ≤ 0.05-0.01; ES range: 0.36-1.20). A large correlation during the Max protocol between SmO2 and HR (r: 0.931; P ≤ 0.01), and also between SmO2 and BLa was obtained at TP1 (r: 0.722; P ≤ 0.05). A range of moderate-to-large correlations was revealed for SmO2/HR, and BLa/HR for TP2 and TP3 after both protocols (r range: 0.595-0.728; P ≤ 0.05) were executed. SmO2 is a novel parameter that can be used when aiming for a comprehensive evaluation of competitive swimmers' acute responses to sprint interval swimming, in conjunction with HR and BLa.

9.
Nutrients ; 13(6)2021 Jun 03.
Article in English | MEDLINE | ID: mdl-34205138

ABSTRACT

The pandemic of Coronavirus Disease 2019 (COVID-19) has shocked world health authorities generating a global health crisis. The present study discusses the main finding in nutrition sciences associated with COVID-19 in the literature. We conducted a consensus critical review using primary sources, scientific articles, and secondary bibliographic indexes, databases, and web pages. The method was a narrative literature review of the available literature regarding nutrition interventions and nutrition-related factors during the COVID-19 pandemic. The main search engines used in the present research were PubMed, SciELO, and Google Scholar. We found how the COVID-19 lockdown promoted unhealthy dietary changes and increases in body weight of the population, showing obesity and low physical activity levels as increased risk factors of COVID-19 affection and physiopathology. In addition, hospitalized COVID-19 patients presented malnutrition and deficiencies in vitamin C, D, B12 selenium, iron, omega-3, and medium and long-chain fatty acids highlighting the potential health effect of vitamin C and D interventions. Further investigations are needed to show the complete role and implications of nutrition both in the prevention and in the treatment of patients with COVID-19.


Subject(s)
COVID-19 , Communicable Disease Control , Diet , Feeding Behavior , Life Style , Nutritional Status , Pandemics , Exercise , Female , Health Behavior , Hospitalization , Humans , Male , Nutrients/deficiency , Obesity/etiology , SARS-CoV-2
10.
Article in English | MEDLINE | ID: mdl-34068866

ABSTRACT

The actual coronavirus disease 2019 (COVID-19) pandemic has led to the limit of emergency systems worldwide, leading to the collapse of health systems, police, first responders, as well as other areas. Various ways of dealing with this world crisis have been proposed from many aspects, with fuzzy multi-criteria decision analysis being a method that can be applied to a wide range of emergency systems and professional groups, aiming to confront several associated issues and challenges. The purpose of this critical review was to discuss the basic principles, present current applications during the first pandemic wave, and propose future implications of this methodology. For this purpose, both primary sources, such as scientific articles, and secondary ones, such as bibliographic indexes, web pages, and databases, were used. The main search engines were PubMed, SciELO, and Google Scholar. The method was a systematic literature review of the available literature regarding the performance of the fuzzy multi-criteria decision analysis of emergency systems in the COVID-19 pandemic. The results of this study highlight the importance of the fuzzy multi-criteria decision analysis method as a beneficial tool for healthcare workers and first responders' emergency professionals to face this pandemic as well as to manage the created uncertainty and its related risks.


Subject(s)
COVID-19 , Pandemics , Decision Support Techniques , Health Personnel , Humans , SARS-CoV-2
11.
Cardiol Res Pract ; 2020: 7986249, 2020.
Article in English | MEDLINE | ID: mdl-32850146

ABSTRACT

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 psychophysiological adversity. Regarding military population, military operations and combat exposure are important stressors that influence acute and chronic stress response in soldiers, affecting their performance and health. A bibliographic search was carried out between April and May 2019, focusing on recent studies (2013-2019) that analysed psychophysiological response, stress, stress regulation, heart rate, heart rate variability, and posttraumatic stress disorder in military population. Autonomic and cardiovascular chronic stress seems to be modulated by experience and previous specific training of each military unit. Physical exercise, music embedded with binaural beat technology, bidirectional sensory motor rhythm training, heart rate variability biofeedback, and transcutaneous vagal nerve stimulation are the main techniques applied to balance stress and to recover body homeostasis. Since military population are usually exposed to multiple stressors, knowing previous training and experience, together with developing techniques to balance stress, is the main practical application in this field of study to balance autonomic and cardiovascular systems.

12.
Article in English | MEDLINE | ID: mdl-32456109

ABSTRACT

In recent years, the interest of female dominance in long-distance swimming has grown where several newspaper articles have been published speculating about female performance and dominance-especially in open-water ultra-distance swimming. The aim of this narrative review is to review the scientific literature regarding the difference between the sexes for all swimming strokes (i.e., butterfly, backstroke, breaststroke, freestyle and individual medley), different distances (i.e., from sprint to ultra-distances), extreme conditions (i.e., cold water), different ages and swimming integrated in multi-sports disciplines, such as triathlon, in various age groups and over calendar years. The influence of various physiological, psychological, anthropometrical and biomechanical aspects to potentially explain the female dominance was also discussed. The data bases Scopus and PUBMED were searched by April 2020 for the terms 'sex-difference-swimming'. Long-distance open-water swimmers and pool swimmers of different ages and performance levels were mainly investigated. In open-water long-distance swimming events of the 'Triple Crown of Open Water Swimming' with the 'Catalina Channel Swim', the 'English Channel Swim' and the 'Manhattan Island Marathon Swim', women were about 0.06 km/h faster than men. In master swimmers (i.e., age groups 25-29 to 90-94 years) competing in the FINA (Fédération Internationale de Natation) World Championships in pool swimming in freestyle, backstroke, butterfly, breaststroke, individual medley and in 3000-m open-water swimming, women master swimmers appeared able to achieve similar performances as men in the oldest age groups (i.e., older than 75-80 years). In boys and girls aged 5-18 years-and listed in the all-time top 100 U.S. freestyle swimming performances from 50 m to 1500 m-the five fastest girls were faster than the five fastest boys until the age of ~10 years. After the age of 10 years, and until the age of 17 years, however, boys were increasingly faster than girls. Therefore, women tended to decrease the existing sex differences in specific age groups (i.e., younger than 10 years and older than 75-80 years) and swimming strokes in pool-swimming or even to overperform men in long-distance open-water swimming (distance of ~30 km), especially under extreme weather conditions (water colder than ~20 °C). Two main variables may explain why women can swim faster than men in open-water swimming events: (i) the long distance of around 30 km, (ii) and water colder than ~20 °C. Future studies may investigate more detailed (e.g., anthropometry) the very young (<10 years) and very old (>75-80 years) age groups in swimming.


Subject(s)
Athletic Performance , Swimming , Adolescent , Child , Child, Preschool , Female , Humans , Male , Sex Characteristics , Sex Factors
13.
Front Psychol ; 11: 580225, 2020.
Article in English | MEDLINE | ID: mdl-33391099

ABSTRACT

The Coronavirus Disease 2019 (COVID-19) pandemic, now a global health crisis, has surprised health authorities around the world. Recent studies suggest that the measures taken to curb the spread of the COVID-19 outbreak have generated issues throughout the population. Thus, it is necessary to establish and identify the possible risk factors related to the psychosocial and psychophysiological strain during the COVID-19 outbreak. The present extensive literature review assesses the social, psychological, and physiological consequences of COVID-19, reviewing the impact of quarantine measures, isolation, vast human loss, social and financial consequences in the family's economies, and its impact on the psychological health of the population. We also discussed the effect of psychophysiological factors, considering the impact of physical inactivity and modifications in nutritional habits, at psychological and physiological levels. The present review includes an actualized to date bibliography, articles for which were methodologically analyzed to verify they met the standards of quality and scientific accuracy. Authors understand the pandemic as a multifactorial event for which only a profound and extensive analysis would lead to better compression and efficient intervention in the near future.

14.
Physiol Behav ; 204: 106-111, 2019 05 15.
Article in English | MEDLINE | ID: mdl-30794850

ABSTRACT

Athletes' competitive level has an effect on several psychophysiological parameters during the execution of sports-related tasks. This study analyzed the acute effect of a potentiation activity (PAP), composed by 5 loaded box jumps, on specific psychological, physiological and performance-related parameters in 22 trained (COM) and untrained (UNT) adult male swimmers. A control condition was also evaluated. Measurements included the Competitive State Anxiety Inventory, rate of perceived exertion, lower limbs muscle oxygenation, exercise heart rate, vertical jumping ability, 3 different split times and total time-trial performance during an all-out 50-m swim test executed using the breaststroke technique. In addition, total swim strokes and the optimal individual response after the potentiation activity were measured. No significant differences among the two testing conditions were found for all psychological, physiological and performance-related parameters (p > .05) with the exception of total performance time in the UNT group after the PAP condition (41.5 ±â€¯5.3 vs. 41.9 ±â€¯5.5 s; p = .023; ES = 0.6). As expected, the COM group showed enhanced swimming performance during all split times and total time, compared to the UNT group. These results suggest that (i) independently of the training level, psychological responses during sports-related tasks are probably not evident under non-competitive situations and, (ii) competitive level athletes may need more challenging activation stimulus, compared to their less competitive counterparts, to induce the desirable adaptations on the subsequent main activity.


Subject(s)
Athletic Performance/psychology , Competitive Behavior , Swimming/psychology , Anxiety/psychology , Athletes/psychology , Heart Rate , Humans , Lower Extremity , Male , Oxygen Consumption , Young Adult
15.
Front Physiol ; 10: 1507, 2019.
Article in English | MEDLINE | ID: mdl-31920712

ABSTRACT

Ultra-endurance races are one of the most physically and psychologically demanding sports, depending performance on several elements. The aims of the present study were (i) to analyze differences in selected psychophysiological parameters between finisher and non-finisher ultra-endurance mountain athletes, and (ii) to analyze modifications in psychophysiological parameters before and after an ultra-endurance mountain event. Selected psychophysiological variables were assessed in 46 finishers and 24 non-finishers in two over 100 km ultra-endurance races were examined. We found how an ultra-endurance mountain race produced dehydration, a decrease in systolic blood pressure, weight and leg strength muscle values, as well as an increase in heart rate and rate of perceived exertion values. Finishers presented lower systolic blood pressure, weight, body mass index, half marathon time and fluid intake before competition day compared to non-finishers. In addition, body mass index, pre-race hydration, and performance in lower distance races were predictors of performance in these ultra-endurance mountain races.

16.
J Sports Med Phys Fitness ; 58(1-2): 1-7, 2018.
Article in English | MEDLINE | ID: mdl-27813393

ABSTRACT

BACKGROUND: This study compared the effect of two training strategies differing on the weekly intensity distribution on physiological parameters and running performance in moderately trained endurance athletes. METHODS: Thirty male athletes were equally divided into three groups, one following an increasing weekly aerobic intensity distribution (EXP1), one with constant weekly aerobic intensity distribution (EXP2) and a control one, following a freely chosen program (CON). Before the training intervention, athletes performed a maximal exercise treadmill test to quantify the different zones allowing training to be controlled, based on blood lactate concentration values (BLa), over a 4-week period. Changes in exercise heart rate (HR), running velocity and rate of perceived exertion at three exercise intensities corresponding to 2.5, 4 and 8 mmol·L-1 of BLa were analyzed at three testing conditions: before (pre), after two (mid) and four weeks (post). RESULTS: A significant increase (P≤0.05) in running velocity at the intensity of 8 mmol·L-1 in EXP1 group was revealed at mid (5.5%) and postcondition (11.5%), while EXP2 group showed a significant decrease in exercise HR at 4 mmol·L-1 between pre- (6.7%) and post-condition (9.0%) (P≤0.05). The rest of the examined variables showed only trivial changes in both experimental groups at all testing conditions (P>0.05). In addition, no changes were observed in CON group in any of the variables tested. CONCLUSIONS: These results demonstrate that depending on the training goal, different intensity variation strategies should be followed to induce the desired adaptations.


Subject(s)
Athletic Performance/physiology , Running/physiology , Adaptation, Physiological , Adult , Athletes/statistics & numerical data , Exercise , Exercise Test , Heart Rate , Humans , Lactic Acid/blood , Male , Middle Aged , Physical Endurance/physiology , Young Adult
17.
J Strength Cond Res ; 30(10): 2871-9, 2016 Oct.
Article in English | MEDLINE | ID: mdl-26849791

ABSTRACT

Dalamitros, AA, Zafeiridis, AS, Toubekis, AG, Tsalis, GA, Pelarigo, JG, Manou, V, and Kellis, S. Effects of short-interval and long-interval swimming protocols on performance, aerobic adaptations, and technical parameters: A training study. J Strength Cond Res 30(10): 2871-2879, 2016-This study compared 2-interval swimming training programs of different work interval durations, matched for total distance and exercise intensity, on swimming performance, aerobic adaptations, and technical parameters. Twenty-four former swimmers were equally divided to short-interval training group (INT50, 12-16 × 50 m with 15 seconds rest), long-interval training group (INT100, 6-8 × 100 m with 30 seconds rest), and a control group (CON). The 2 experimental groups followed the specified swimming training program for 8 weeks. Before and after training, swimming performance, technical parameters, and indices of aerobic adaptations were assessed. ΙΝΤ50 and ΙΝΤ100 improved swimming performance in 100 and 400-m tests and the maximal aerobic speed (p ≤ 0.05); the performance in the 50-m swim did not change. Posttraining V[Combining Dot Above]O2max values were higher compared with pretraining values in both training groups (p ≤ 0.05), whereas peak aerobic power output increased only in INT100 (p ≤ 0.05). The 1-minute heart rate and blood lactate recovery values decreased after training in both groups (p < 0.01). Stroke length increased in 100 and 400-m swimming tests after training in both groups (p ≤ 0.05); no changes were observed in stroke rate after training. Comparisons between groups on posttraining mean values, after adjusting for pretraining values, revealed no significant differences between ΙΝΤ50 and ΙΝΤ100 for all variables; however, all measures were improved vs. the respective values in the CON (p < 0.001-0.05). In conclusion, when matched for distance and exercise intensity, the short-interval (50 m) and long-interval (100 m) protocols confer analogous improvements in swimming performance, in stroke cycle parameters, and in indices of aerobic adaptations after 8 weeks of training.


Subject(s)
Adaptation, Physiological/physiology , Athletic Performance/physiology , Exercise/physiology , Physical Fitness/physiology , Swimming/physiology , Heart Rate , Humans , Male , Young Adult
18.
J Hum Kinet ; 49: 195-200, 2015 Dec 22.
Article in English | MEDLINE | ID: mdl-26839619

ABSTRACT

Previous studies demonstrated significant increases in the shoulder internal rotators' peak torque values and unilateral muscular imbalances of the shoulder rotators after a competitive swim period. However, there are no similar data concerning the knee muscles. The purpose of the current study was to examine the effects of a six-month training period on knee flexor and extensor peak torque values, examine a possible bilateral strength deficit and evaluate the unilateral strength balance in competitive swimmers. Eleven male adolescent swimmers (age: 14.82 ± 0.45 years) were tested for concentric knee extension and flexion peak torque (60°/s) with an isokinetic dynamometer, before and after a regular combined swim and dry-land strength training period. A trend towards greater improvements in the knee extensor compared to flexor muscles peak torque was observed. Furthermore, the bilateral strength deficit remained almost unchanged, whereas unilateral strength imbalance was increased for both limbs. However, all results were non-significant (p > 0.05). According to the data presented, a six-month regular combined swim and dry-land strength training period caused non-significant alterations for all the parameters evaluated during isokinetic testing. This study highlights the fact that competitive adolescent swimmers demonstrated unilateral knee strength imbalances throughout a long period of their yearly training macrocycle.

19.
J Strength Cond Res ; 29(7): 1830-6, 2015 Jul.
Article in English | MEDLINE | ID: mdl-24513615

ABSTRACT

This study examines the relationship between speed reserve (SRes), critical swimming speed (CSS), and anaerobic distance capacity (ADC) and their efficacy in determining training adaptations. Swimmers with previous competitive experience participated in an 8-week aerobic training program (experimental group: E; n = 15, age: 22.29 ± 0.95 years) and a control group refrained from training during the same period (C; n = 6, age: 22.25 ± 2.22 years). Speed reserve was determined before and after training from the speed difference between the 50 and 400 m maximum tests. Both CSS and ADC were calculated using 2 different combinations of distances (50 and 400 m: CSS2/ADC2; 50, 100, and 400 m: CSS3/ADC3) by applying the distance-time linear regression model. CSS2 and CSS3 of the E group showed a negative correlation, whereas ADC2 and ADC3 showed a positive correlation, with SRes before and after the training period (r ≥ -0.66, r ≥ 0.88, p ≤ 0.05). CSS2 and CSS3 increased by 5.5 ± 3.2 and 6.0 ± 3.2%, whereas ADC2, ADC3, and SRes decreased by 12.0 ± 9.4, 9.0 ± 11.2, and 8.1 ± 8.4% with the training program (p ≤ 0.05). These findings suggest that SRes, as calculated from distances of 50 and 400 m, shows strong relationships with CSS and ADC and may be used as an indicator of training-induced changes. This information is expected to facilitate training control and evaluation in a day-to-day basis.


Subject(s)
Anaerobic Threshold/physiology , Athletic Performance/physiology , Swimming/physiology , Adult , Female , Humans , Linear Models , Male
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