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Physiological Responses During Exercise

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A special issue of Sports (ISSN 2075-4663).

Deadline for manuscript submissions: closed (31 December 2018) | Viewed by 94074

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Special Issue Editors

Assoc. Prof. Argyris Toubekis

E-Mail Website1 Website2
Guest Editor

School of Physical Education and Sport Science, National and Kapodistrian University of Athens, 17237 Athens, Greece
Interests: swimming training and performance; training load; swimming physiology; recovery and performance; energy contribution
Special Issues, Collections and Topics in MDPI journals

Dr. Petros Botonis

E-Mail Website
Guest Editor

Department of Aquatic Sports, School of Physical Education and Sports Science, University of Athens, 157 72 Athens, Greece
Interests: aquatic sports; sports performance optimization; fatigue and recovery
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Athletes in all sports, and exercising people, use various types of exercise and several combinations of exercise modes in their regular training. Each mode and type of exercise presents unique characteristics and difficulties related to its duration, intensity, rest interval duration the environmental conditions and personal abilities. The physiological responses of any exercise type may reflect muscular, cardiovascular, metabolic, hormonal, energetic and several other regulatory alterations. Advancing the knowledge and understanding of physiological responses in all types of exercise will facilitate training planning for performance enhancement and health benefits. This Special Issue within Sports, entitled “Physiological Responses During Exercise”, will accept experimental research, including literature reviews, as applied to any mode and type of exercise. A 50% discount for a future publication in "Sports" will be offered to the three best accepted papers as selected by the editors.

Assist. Prof. Argyris Toubekis
Dr. Petros Botonis
Guest Editors

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Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Sports is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

metabolism
performance
health
interval exercise
continous exercise
young athletes
individual and team-sports
environment

Published Papers (13 papers)

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Research

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9 pages, 5116 KiB

Open AccessArticle

Heart Rate Kinetics Response of Pre-Pubertal Children during the Yo-Yo Intermittent Endurance Test—Level 1

by João Brito, Luís Fernandes, António Rebelo, Peter Krustrup, Gustavo Silva and José Oliveira

Sports 2019, 7(3), 65; https://0-doi-org.brum.beds.ac.uk/10.3390/sports7030065 - 15 Mar 2019

Cited by 3 | Viewed by 3139

Abstract

This study analyzed heart rate (HR) kinetics during the Yo-Yo Intermittent Endurance Test—level 1 (Yo-Yo IE1) in children. At the middle of the school year, 107 boys (7–10 years old) performed the Yo-Yo IE1. Individual HR curves during the Yo-Yo IE1 were analyzed to detect an inflection point between an initial phase of fast rise in HR, and a second phase in which the rise of HR is slower. The 7^th shuttle of the test was established as the inflection point. Engagement with extra-school sports practice was identified. Percentile groups (P₁, P₂ and P₃) were created for body weight and physical fitness data composite (PF_composite). Differences were found between the slopes of P₁ and P₃ on phase 1 for body weight (12.5 ± 2.7 vs. 13.7 ± 2.0 bpm/shuttle; p = 0.033; d = 0.50) and PF_composite (14.2 ± 2.5 vs. 12.5 ± 2.0 bpm/shuttle; p = 0.015; d = 0.75). Time spent >95% of peak HR was longer for the children engaged with extra-school sports practice (335 ± 158 vs. 234 ± 124 s; p < 0.001; d = 0.71); differences were also detected for PF_composite (P₁, P₂ and P₃: 172 ± 92, 270 ± 109, and 360 ± 157 s, respectively; p < 0.05; d = 0.66–1.46). This study indicates that physical fitness and body weight influence HR kinetics during the Yo-Yo IE1 in pre-pubertal boys. Full article

(This article belongs to the Special Issue Physiological Responses During Exercise)

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9 pages, 715 KiB

Open AccessFeature PaperArticle

Physiological and Biomechanical Evaluation of a Training Macrocycle in Children Swimmers

by Sara Ferreira, Diogo Carvalho, Ana Sofia Monteiro, José Arturo Arturo Abraldes, João Paulo Vilas-Boas, Argyris Toubekis and Ricardo Fernandes

Sports 2019, 7(3), 57; https://0-doi-org.brum.beds.ac.uk/10.3390/sports7030057 - 04 Mar 2019

Cited by 12 | Viewed by 4330

Abstract

Physiological responses related to 400-m front crawl performance were examined in a 11-week training macrocycle in children 11.6 ± 1.2 years old. Fourteen girls and twenty-nine boys completed a maximum intensity 400-m test, at the beginning (Τ1) and at the end of four weeks of general preparation (Τ2), four weeks of specific preparation (Τ3), and three weeks of the competitive period (Τ4). Blood lactate (La), blood glucose (Glu) and heart rate were measured post effort. Stroke rate (SR), stroke length (SL) and stroke index (SI) were measured during the test. The 400-m time was decreased at T2, T3, and T4 compared to T1 by 4.2 ± 4.9, 7.5 ± 7.0, and 8.6 ± 7.3% (p < 0.05) and at T3 and T4 compared to T2 by 3.1 ± 4.3 and 4.2 ± 4.6%, respectively (p < 0.05). La was not different between tests (p > 0.05) and Glu was decreased at T3 compared to other testing moments (p < 0.05). SR, SL, and SI were higher at T3 and T4 compared to T1 (p < 0.05). SL and SI were also increased at T4 compared to T2 (p < 0.05). Performance changes from T1 to T2 were related to SL and SI changes (r = 0.45 and 0.83, p < 0.05), and subsequent changes between T2 to T3 were related to SR, SI, La, and Glu changes (r = 0.48, 0.68, 0.34, and 0.42, p < 0.05). Performance change from T3 to T4 was related to SL, SI, and La modifications (r = 0.34, 0.70, and 0.53, p < 0.05). Performance gains may be related to various biomechanical or physiological changes according to training macrocycle structure. Full article

(This article belongs to the Special Issue Physiological Responses During Exercise)

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10 pages, 1044 KiB

Open AccessArticle

Gastrocnemius Medialis Architectural Properties at Rest and During Stretching in Female Athletes with Different Flexibility Training Background

by Olyvia Donti, Ioli Panidis, Gerasimos Terzis and Gregory C. Bogdanis

Sports 2019, 7(2), 39; https://0-doi-org.brum.beds.ac.uk/10.3390/sports7020039 - 13 Feb 2019

Cited by 11 | Viewed by 4414

Abstract

Background: This study examined gastrocnemius medialis (GM) architectural properties and ankle joint range of motion (ROM) between female athletes with different flexibility training background. Methods: Elite rhythmic gymnasts (n = 10) were compared to national level volleyball athletes (n = 10). Fascicle length, pennation angle and muscle thickness at the medial and the distal part of GM, and ankle ROM were measured at rest and during 1 min of static stretching. Results: At rest, rhythmic gymnasts displayed longer fascicles compared to volleyball athletes, at the medial (5.93 ± 0.27 vs. 4.74 ± 0.33 mm, respectively, p = 0.001) and the distal part of GM (5.63 ± 0.52 vs. 4.57 ± 0.51 mm, respectively, p = 0.001), smaller pennation angle at the medial part (22.4 ± 2.5 vs. 25.8 ± 2.4°; respectively, p = 0.001) and greater ankle angle (121.7 ± 4.1 vs. 113.2 ± 3.7°, respectively, p = 0.001). During the 1 min of static stretching, gymnasts displayed greater fascicle elongation at the distal part (p = 0.026), greater maximal ankle dorsiflexion (p < 0.001) and muscle tendon junction displacement (p < 0.001) with no difference between groups in pennation angles (p > 0.145), muscle thickness (p > 0.105), and fascicle elongation at mid-belly (p = 0.063). Conclusions: Longer muscle fascicles at rest and greater fascicle elongation at the distal part of GM may contribute to the greater ankle ROM observed in rhythmic gymnasts. Full article

(This article belongs to the Special Issue Physiological Responses During Exercise)

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15 pages, 6404 KiB

Open AccessArticle

VO₂FITTING: A Free and Open-Source Software for Modelling Oxygen Uptake Kinetics in Swimming and other Exercise Modalities

by Rodrigo Zacca, Rui Azevedo, Pedro Figueiredo, João Paulo Vilas-Boas, Flávio A. de S. Castro, David B. Pyne and Ricardo J. Fernandes

Sports 2019, 7(2), 31; https://0-doi-org.brum.beds.ac.uk/10.3390/sports7020031 - 24 Jan 2019

Cited by 15 | Viewed by 6494

Abstract

The assessment of oxygen uptake (VO₂) kinetics is a valuable non-invasive way to evaluate cardiorespiratory and metabolic response to exercise. The aim of the study was to develop, describe and evaluate an online VO₂ fitting tool (VO₂FITTING) for dynamically editing, processing, filtering and modelling VO₂ responses to exercise. VO₂FITTING was developed in Shiny, a web application framework for R language. Validation VO₂ datasets with both noisy and non-noisy data were developed and applied to widely-used models (n = 7) for describing different intensity transitions to verify concurrent validity. Subsequently, we then conducted an experiment with age-group swimmers as an example, illustrating how VO₂FITTING can be used to model VO₂ kinetics. Perfect fits were observed, and parameter estimates perfectly matched the known inputted values for all available models (standard error = 0; p < 0.001). The VO₂FITTING is a valid, free and open-source software for characterizing VO₂ kinetics in exercise, which was developed to help the research and performance analysis communities. Full article

(This article belongs to the Special Issue Physiological Responses During Exercise)

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11 pages, 955 KiB

Open AccessFeature PaperArticle

Physiological Responses of Continuous and Intermittent Swimming at Critical Speed and Maximum Lactate Steady State in Children and Adolescent Swimmers

by Ioannis S. Nikitakis, Giorgos P. Paradisis, Gregory C. Bogdanis and Argyris G. Toubekis

Sports 2019, 7(1), 25; https://0-doi-org.brum.beds.ac.uk/10.3390/sports7010025 - 18 Jan 2019

Cited by 9 | Viewed by 4564

Abstract

Background: The purpose of this study was to compare physiological responses during continuous and intermittent swimming at intensity corresponding to critical speed (CS: slope of the distance vs. time relationship using 200 and 400-m tests) with maximal lactate steady state (MLSS) in children and adolescents. Methods: CS and the speed corresponding to MLSS (sMLSS) were calculated in ten male children (11.5 ± 0.4 years) and ten adolescents (15.8 ± 0.7 years). Blood lactate concentration (BL), oxygen uptake (

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O₂), and heart rate (HR) at sMLSS were compared to intermittent (10 × 200-m) and continuous swimming corresponding to CS. Results: CS was similar to sMLSS in children (1.092 ± 0.071 vs. 1.083 ± 0.065 m·s⁻¹; p = 0.12) and adolescents (1.315 ± 0.068 vs. 1.297 ± 0.056 m·s⁻¹; p = 0.12). However, not all swimmers were able to complete 30 min at CS and BL was higher at the end of continuous swimming at CS compared to sMLSS (children: CS: 4.0 ± 1.8, sMLSS: 3.4 ± 1.5; adolescents: CS: 4.5 ± 2.3, sMLSS: 3.1 ± 0.8 mmol·L⁻¹; p < 0.05).

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O₂ and HR in continuous swimming at CS were not different compared to sMLSS (p > 0.05). BL,

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O₂ and HR in 10 × 200-m were similar to sMLSS and no different between groups. Conclusion: Intermittent swimming at CS presents physiological responses similar to sMLSS. Metabolic responses of continuous swimming at CS may not correspond to MLSS in some children and adolescent swimmers. Full article

(This article belongs to the Special Issue Physiological Responses During Exercise)

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8 pages, 200 KiB

Open AccessArticle

Core Temperature Responses in Elite Cricket Players during Australian Summer Conditions

by Sharon Stay, Michelle Cort, David Ward, Alex Kountouris, John Orchard, Justin Holland and Anna Saw

Sports 2018, 6(4), 164; https://0-doi-org.brum.beds.ac.uk/10.3390/sports6040164 - 05 Dec 2018

Cited by 5 | Viewed by 4472

Abstract

This study aimed to observe core temperature responses in elite cricket players under match conditions during the summer in Australia. Thirty-eight Australian male cricketers ingested capsule temperature sensors during six four-day first-class matches between February 2016 and March 2017. Core temperature (Tc) was recorded during breaks in play. Batters showed an increase in Tc related to time spent batting of approximately 1 °C per two hours of play (p < 0.001). Increases in rate of perceived exertion (RPE) in batters correlated with smaller elevations in Tc (0.2 °C per one unit of elevation in RPE) (p < 0.001). Significant, but clinically trivial, increases in Tc of batters were found related to the day of play, wet bulb globe temperature (WBGT), air temperature, and humidity. A trivial increase in Tc (p < 0.001) was associated with time in the field and RPE when fielding. There was no association between Tc and WBGT, air temperature, humidity, or day of play in fielders. This study demonstrates that batters have greater rises in Tc than other cricket participants, and may have an increased risk of exertional heat illness, despite exposure to similar environmental conditions. Full article

(This article belongs to the Special Issue Physiological Responses During Exercise)

6 pages, 481 KiB

Open AccessArticle

Evaluation of Physical Fitness in Water Polo Players According to Playing Level and Positional Role

by Petros G. Botonis, Argyris G. Toubekis and Theodoros I. Platanou

Sports 2018, 6(4), 157; https://0-doi-org.brum.beds.ac.uk/10.3390/sports6040157 - 28 Nov 2018

Cited by 13 | Viewed by 5083

Abstract

Background: We aimed to investigate whether water polo players of different playing levels and positions differ in fitness parameters (i.e., strength, aerobic endurance, and anaerobic potential). Methods: Twenty-four water polo players were assigned to international- (IL) and national-level (NL) groups or to centers and peripherals. At the beginning of preseason training, maximal bench press strength was measured and a speed–lactate test (5 × 200m) was performed to determine the speed corresponding to lactate concentrations of 4.0 (V4), 5.0 (V5), and 10.0 (V10) mmol·L⁻¹. Results: Maximal muscular strength was similar between international- and national-level water polo players, but it was higher in centers than in peripherals (109.2 ± 12.2 kg vs. 96.9 ± 8.5 kg, p = 0.007). IL players showed higher V4, V5, and V10 compared to NL players (V4, IL: 1.27 ± 0.04 m·s⁻¹ vs. NL: 1.17 ± 0.06 m·s⁻¹), (V5, IL: 1.33 ± 0.03 m·s⁻¹ vs. NL: 1.22 ± 0.05 m·s⁻¹), and V10 (IL: 1.50 ± 0.31 vs. NL: 1.35 ± 0.06 m·s⁻¹) (p < 0.01)). However, no significant differences were detected between centers and peripherals inV4, V5, and V10. Conclusions: We suggest that V4, V5, and V10 distinguish playing level in water polo, whereas they are comparable between playing positions. Although maximal strength is similar between playing levels, it is different between playing positions. Full article

(This article belongs to the Special Issue Physiological Responses During Exercise)

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9 pages, 365 KiB

Open AccessArticle

by Paul S. Hafen and Pat R. Vehrs

Sports 2018, 6(4), 154; https://0-doi-org.brum.beds.ac.uk/10.3390/sports6040154 - 27 Nov 2018

Cited by 7 | Viewed by 6083

Abstract

The maximal lactate steady state (MLSS) is one of the factors that differentiates performance in aerobic events. The purpose of this study was to investigate the sex differences in oxygen consumption (VO₂), heart rate (HR), and the respiratory exchange ratio (RER) at the MLSS in well-trained distance runners. Twenty-two (12 female, 10 male) well-trained distance runners (23 ± 5.0 years) performed multiple 30-min steady-state runs to determine their MLSS, during which blood lactate and respiratory gas exchange measures were taken. To interpret the MLSS intensity as a training tool, runners completed a time-to-exhaustion (TTE) run at their MLSS. The relative intensity at which the MLSS occurred was identical between males and females according to both oxygen consumption (83 ± 5 %O₂max) and heart rate (89 ± 7 %HRmax). However, female runners displayed a significantly lower RER at MLSS compared to male runners (p < 0.0001; 0.84 ± 0.02 vs. 0.88 ± 0.04, respectively). There was not a significant difference in TTE at MLSS between males (79 ± 17 min) and females (80 ± 25 min). Due to the observed difference in the RER at the MLSS, it is suggested that RER derived estimates of MLSS be sex-specific. While the RER data suggest that the MLSS represents different metabolic intensities for males and females, the relative training load of MLSS appears to be similar in males and female runners. Full article

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11 pages, 685 KiB

Open AccessArticle

Carbohydrate Supplementation Does Not Improve 10 km Swimming Intermittent Training

by Roberto Baldassarre, Massimo Sacchetti, Federica Patrizio, Andrea Nicolò, Alessandro Scotto di Palumbo, Marco Bonifazi and Maria Francesca Piacentini

Sports 2018, 6(4), 147; https://0-doi-org.brum.beds.ac.uk/10.3390/sports6040147 - 14 Nov 2018

Cited by 2 | Viewed by 3735

Abstract

The aim of the present study was to test the effectiveness of carbohydrate (CHO) feeding supplemented every 2.5-km, as in official races, on the performance, rating of perceived exertion (RPE), and glycaemia during a 10-km intermittent training workout in elite open-water swimmers. A randomized crossover design was used. Participants completed two 10-km intermittent training sessions (20 × 500-m). The relative velocity was expressed in percentage of a single 500-m. Glycaemia was monitored by continuous glucose monitoring. Participants had to ingest either 1 L of tap water (WAT; 0.50 L·h⁻¹) or 120 g of CHO in the form of 8% solution (60 g·h⁻¹). The 15-point RPE scale was used during the trials. A two-way ANOVA for repeated measures was performed (p < 0.05). The relative velocity of each 500-m was not significantly different between the two trials. No significant differences emerged in the relative velocity of the last 500-m between trials. Average RPE was not statistically different between the two trials (11 ± 3 in WAT and 12 ± 3 in CHO). In the last 500-m, glycaemia was significantly higher in the CHO trial (5.92 ± 0.47 mmol·L⁻¹ in CHO; 5.61 ± 0.61 mmol·L⁻¹ in WAT). CHO ingestion did not improve performance or affect RPE during a 10-km intermittent training in elite open-water swimmers. Full article

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7 pages, 760 KiB

Open AccessArticle

Moderate Intensity Intermittent Exercise Modality May Prevent Cardiovascular Drift

by Muzaffer Colakoglu, Ozgur Ozkaya and Gorkem Aybars Balci

Sports 2018, 6(3), 98; https://0-doi-org.brum.beds.ac.uk/10.3390/sports6030098 - 15 Sep 2018

Cited by 1 | Viewed by 5181

Abstract

Cardiovascular drift (CV-Drift) may occur after the ~10th min of submaximal continuous exercising. The purpose of this study was to examine whether CV-Drift is prevented by an intermittent exercise modality, instead of a continuous exercise. Seven well-trained male cyclists volunteered to take part [...] Read more.

\dot{V}

O_2max: 61.7 ± 6.13 mL·min⁻¹·kg⁻¹). Following familiarization sessions, athletes’ individual maximal O₂ consumption (

\dot{V}

O_2max), maximum stroke volume responses (SV_max), and cardiac outputs (Qc) were evaluated by a nitrous-oxide re-breathing system and its gas analyzer. Then, continuous exercises were performed 30 min at cyclists’ 60%

\dot{V}

O_2max, while intermittent exercises consisted of three 10 min with 1:0.5 workout/recovery ratios at the same intensity. Qc measurements were taken at the 5th, 9th, 12nd, 15th, 20th, 25th, and 30th min of continuous exercises versus 5th and 10th min of workout phases of intermittent exercise modality. Greater than a 5% SV decrement, with accompanying HR, increase, while Qc remained stable and was accepted as CV-Drift criterion. It was demonstrated that there were greater SV responses throughout intermittent exercises when compared to continuous exercises (138.9 ± 17.9 vs. 144.5 ± 14.6 mL, respectively; p ≤ 0.05) and less HR responses (140.1 ± 14.8 vs. 135.2 ± 11.6 bpm, respectively; p ≤ 0.05), while mean Qc responses were similar (19.4 ± 2.1 vs. 19.4 ± 1.5 L, respectively; p > 0.05). Moreover, the mean times spent at peak SV scores of exercise sessions were greater during intermittent exercise (1.5 vs. 10 min) (p < 0.001). In conclusion, intermittent exercises reduce CV-Drift risk and increases cardiac adaptation potentials of exercises with less physiological stress. Full article

(This article belongs to the Special Issue Physiological Responses During Exercise)

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9 pages, 630 KiB

Open AccessArticle

Adolescent Finswimmers: Early Myocardial Adaptations in Different Swimming Styles

by Vasileios Stavrou, Konstantinos Tsarouhas, Eleni Karetsi, Panagiotis Michos, Zoe Daniil and Konstantinos I. Gourgoulianis

Sports 2018, 6(3), 78; https://0-doi-org.brum.beds.ac.uk/10.3390/sports6030078 - 10 Aug 2018

Cited by 4 | Viewed by 3757

Abstract

Background: The purpose of our study was to investigate early differences in the adolescent female finswimmers’ echocardiography parameters, possibly associated with different swimming-style training and different training equipment (monofin (MF) versus bifin (BF)). Method: Forty-three female finswimmers participated in our study (age: 15.6 ± 2.1 years, body mass index: 20.4 ± 2.2 kg/m², body surface area: 1.56 ± 0.04 m², body fat: 11.2 ± 0.6%) and were divided into two groups, according to the swimming style practiced (MF vs BF). Anthropometric characteristics, echocardiography and arterial pressure were measured. The independent t-test was used for statistical comparisons between groups. Stepwise multivariate regression analysis was applied to investigate associations between various variables. Results: The two groups used training equipment with different weights (p < 0.001). Female adolescent finswimmers presented signs of myocardial hypertrophy depicted by the increased left ventricle myocardial mass indexed to body surface area (101.34 ± 23.65). Different patterns of myocardial hypertrophy were observed for the two groups; MF swimmers presented concentric hypertrophy, while BF swimmers presented eccentric hypertrophy (relative wall thickness MF = 0.46 ± 0.08 vs BF = 0.39 ± 0.06 cm, p < 0.05). MF swimmers had also higher left ventricular posterior wall diameters (p < 0.05), lower stroke volume values (p < 0.05) and lower ejection fraction (p < 0.05) compared to BF athletes. Conclusion: Adolescent female finswimmers presented different patterns of myocardial hypertrophy possibly related to different training protocols and modes of exercise. Full article

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Review

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15 pages, 843 KiB

Open AccessReview

Monitoring Exercise-Induced Muscle Fatigue and Adaptations: Making Sense of Popular or Emerging Indices and Biomarkers

by George Theofilidis, Gregory C. Bogdanis, Yiannis Koutedakis and Christina Karatzaferi

Sports 2018, 6(4), 153; https://0-doi-org.brum.beds.ac.uk/10.3390/sports6040153 - 26 Nov 2018

Cited by 53 | Viewed by 14685

Abstract

Regular exercise with the appropriate intensity and duration may improve an athlete’s physical capacities by targeting different performance determinants across the endurance–strength spectrum aiming to delay fatigue. The mechanisms of muscle fatigue depend on exercise intensity and duration and may range from substrate depletion to acidosis and product inhibition of adenosinetriphosphatase (ATPase) and glycolysis. Fatigue mechanisms have been studied in isolated muscles; single muscle fibers (intact or skinned) or at the level of filamentous or isolated motor proteins; with each approach contributing to our understanding of the fatigue phenomenon. In vivo methods for monitoring fatigue include the assessment of various functional indices supported by the use of biochemical markers including blood lactate levels and more recently redox markers. Blood lactate measurements; as an accompaniment of functional assessment; are extensively used for estimating the contribution of the anaerobic metabolism to energy expenditure and to help interpret an athlete’s resistance to fatigue during high intensity exercise. Monitoring of redox indices is gaining popularity in the applied sports performance setting; as oxidative stress is not only a fatigue agent which may play a role in the pathophysiology of overtraining syndrome; but also constitutes an important signaling pathway for training adaptations; thus reflecting training status. Careful planning of sampling and interpretation of blood biomarkers should be applied; especially given that their levels can fluctuate according to an athlete’s lifestyle and training histories. Full article

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17 pages, 1038 KiB

Open AccessReview

A Brief Review on Concurrent Training: From Laboratory to the Field

by Spyridon Methenitis

Sports 2018, 6(4), 127; https://0-doi-org.brum.beds.ac.uk/10.3390/sports6040127 - 24 Oct 2018

Cited by 62 | Viewed by 26435

Abstract

The majority of sports rely on concurrent training (CT; e.g., the simultaneous training of strength and endurance). However, a phenomenon called “Concurrent training effect” (CTE), which is a compromise in adaptation resulting from concurrent training, appears to be mostly affected by the interference of the molecular pathways of the underlying adaptations from each type of training segments. Until now, it seems that the volume, intensity, type, frequency of endurance training, as well as the training history and background strongly affect the CTE. High volume, moderate, continuous and frequent endurance training, are thought to negatively affect the resistance training-induced adaptations, probably by inhibition of the Protein kinase B—mammalian target of rapamycin pathway activation, of the adenosine monophosphate-activated protein kinase (AMPK). In contrast, it seems that short bouts of high-intensity interval training (HIIT) or sprint interval training (SIT) minimize the negative effects of concurrent training. This is particularly the case when HIIT and SIT incorporated in cycling have even lower or even no negative effects, while they provide at least the same metabolic adaptations, probably through the peroxisome proliferator-activated receptor-γ coactivator (PGC-1a) pathway. However, significant questions about the molecular events underlying the CTE remain unanswered. Full article

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