scholarly journals Effect of Uni and Bilateral High-Intensity Sustained Isometric Contraction Exercise on Fatigue Related Changes in Quadriceps Femoris

2020 ◽  
Vol 2 (117) ◽  
Author(s):  
Giedrė Jurgelaitienė ◽  
Andrius Šatas ◽  
Dalia Mickevičienė ◽  
Albertas Skurvydas
Keyword(s):  
Isometric Contraction ◽  
High Intensity ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Muscle Length ◽  
Central Fatigue ◽  
Voluntary Contraction ◽  
Capillary Blood ◽  
Peripheral Fatigue

Background. It is well established that different types of exercise can provide central and peripheral fatigue. However, there are conflicting findings in the literature, and a consensus has not been reached regarding the different patterns of different ways of performing exercises when the muscle works at long and short lengths and unilaterally and bilaterally. The purpose of this study was to investigate the effect of muscle length and the high-intensity physical exercise when performing unilaterally and bilaterally on fatigue.Methods. Thirteen young healthy physically active volunteering males participated in the study.  Maximal voluntary and involuntary contraction was observed during the performance of sustained maximal (uni-)bilateral isometric contraction at long and short quadriceps muscle length. Capillary blood lactate concentration and perceived exertion was observed after high-intensity physical exercise.Results. Maximal voluntary contraction (MVC)% decreased significantly and greatly in (uni-)bilateral exercise at long muscle length. CAR% at the appearance of fatigue was greater at long muscle length and did not depend on (uni-)bilateral contraction.Conclusion. When both legs generate force (bilateral contraction), it is possible to observe a decrease in the rate of force development (RFD) but not in the MVC. Movement performed at long muscle length and (uni-)bilaterally has an effect on a greater motor cortex activation and a sense of movement effort and lactate concentration in capillary blood. Keywords: high intensity interval exercise, sustained isometric contraction, central fatigue, peripheral fatigue, bilateral and unilateral contraction.

scholarly journals High-Intensity Intermittent Exercise Performed on the Sand Induces Higher Internal Load Demands in Soccer Players

2021 ◽  
Vol 12 ◽  
Author(s):  
Tiago Cetolin ◽  
Anderson Santiago Teixeira ◽  
Juliano Fernandes da Silva ◽  
Alessandro Haupenthal ◽  
Fábio Yuzo Nakamura ◽  
...  
Keyword(s):  
High Intensity ◽  
Perceived Exertion ◽  
Intermittent Exercise ◽  
Surface Condition ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Physiological Effect ◽  
Rating Of Perceived Exertion ◽  
Soccer Players ◽  
Shuttle Run

This study aimed to examine the acute physiological effect of shuttle-run-based high-intensity intermittent exercise (HIIE) performed at the same relative speed (i. e., 100% PST−CAR) on sand (SAND) and grass (GRASS) in male junior soccer players. Seven Under-23 Brazilian national league (“Série A”) soccer players completed four testing sessions in either SAND or GRASS surface condition. The first two testing sessions consisted of performing a maximal progressive shuttle-run field protocol until volitional exhaustion (Carminatti's test, T-CAR), whereas the third and fourth sessions comprised a HIIE session on each ground surface. The HIIE session consisted of three 5-min bouts [12 s shuttle-run (with a direction change every 6 s)/12 s of passive rest] performed at 100% of T-CAR peak speed (PST−CAR) with 3 min of passive recovery between sets. Measurements of oxygen uptake (VO2), heart rate (HR), blood lactate concentration ([La]), and rating of perceived exertion (RPE) were performed during all conditions. The SAND condition elicited significantly higher %VO2peak (94.58 ± 2.73 vs. 87.45 ± 3.31%, p < 0.001, d = 2.35), %HRpeak (93.89 ± 2.63 vs. 90.31 ± 2.87%, p < 0.001, d = 1.30), RPE (8.00 ± 0.91 vs. 4.95 ± 1.23 a.u., p < 0.001, d = 2.82), and [La] (10.76 ± 2.37 vs. 5.48 ± 1.13 mmol/L, p < 0.010, d = 2.84). This study showed that higher internal workloads are experienced by the players during a single HIIE session performed on a softer surface as SAND, even when the exercise intensity was individualized based on 100%PST−CAR.

Cardiometabolic and Perceptual Responses to Body-Weight Resistance High-Intensity Interval Exercise in Boys

2020 ◽  
pp. 1-8
Author(s):  
Jeanette M. Ricci ◽  
Todd A. Astorino ◽  
Katharine D. Currie ◽  
Karin A. Pfeiffer
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
High Intensity ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Rating Of Perceived Exertion ◽  
Peak Heart Rate ◽  
Interval Exercise ◽  
High Intensity Interval

The majority of studies examining children’s responses to high-intensity interval exercise primarily utilized running; however, this modality does not require/include other important aspects of physical activity including muscular fitness. Purpose: To compare acute responses between a body weight resistance exercise circuit (CIRC) and treadmill-based (TM) high-intensity interval exercise. Method: A total of 17 boys (age = 9.7 [1.3] y) completed a graded exercise test to determine peak heart rate, peak oxygen uptake (VO2peak), and maximal aerobic speed. Sessions were randomized and counterbalanced. CIRC required 2 sets of 30-second maximal repetitions of 4 exercises. TM included eight 30-second bouts of running at 100% maximal aerobic speed. Both included 30-second active recovery between bouts. Blood lactate concentration was measured preexercise and postexercise. Rating of perceived exertion, affective valence, and enjoyment were recorded preexercise, after intervals 3 and 6, and postexercise. Results: Participants attained 88% (5%) peak heart rate and 74% (9%) VO2peak for CIRC and 89% (4%) peak heart rate and 81% (6%) VO2peak for TM, with a significant difference in percentage of VO2peak (P = .003) between protocols. Postexercise blood lactate concentration was higher following CIRC (5.0 [0.7] mM) versus TM (2.0 [0.3] mM) (P < .001). Rating of perceived exertion, affective valence, and enjoyment responses did not differ between protocols (P > .05). Conclusion: HR responses were near maximal during CIRC, supporting that this body-weight circuit is representative of high-intensity interval exercise.

The effect of pre-test carbohydrate ingestion on the anaerobic threshold, as determined by the lactate-minimum test

2007 ◽  
Vol 32 (6) ◽  
pp. 1058-1064 ◽  
Author(s):  
Arie Rotstein ◽  
Raffy Dotan ◽  
Levana Zigel ◽  
Tally Greenberg ◽  
Yael Benyamini ◽  
...  
Keyword(s):  
Anaerobic Threshold ◽  
High Intensity ◽  
Perceived Exertion ◽  
Recovery Period ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Rating Of Perceived Exertion ◽  
Carbohydrate Ingestion ◽  
Glucose Determination ◽  
Lactate Minimum

The purpose of this study was to investigate the effect of pre-test carbohydrate (CHO) ingestion on anaerobic-threshold assessment using the lactate-minimum test (LMT). Fifteen competitive male distance runners capable of running 10 km in 33.5–43 min were used as subjects. LMT was performed following CHO (2 × 300 mL, 7% solution) or comparable placebo (Pl) ingestion, in a double-blind, randomized order. The LMT consisted of two high-intensity 1 min treadmill runs (17–21 km·h–1), followed by an 8 min recovery period. Subsequently, subjects performed 5 min running stages, incremented by 0.6 km·h–1 and separated by 1 min blood-sampling intervals. Tests were terminated after 3 consecutive increases in blood-lactate concentration ([La]) had been observed. Finger-tip capillary blood was sampled for [La] and blood-glucose determination 30 min before the test’s onset, during the recovery phase following the 2 high-intensity runs, and following each of the subsequent 5 min stages. Heart rate (HR) and rating of perceived exertion (RPE) were recorded after each stage. The lactate-minimum speed (LMS) was determined from the individual [La]–velocity plots and was considered reflective of the anaerobic threshold. Pre-test CHO ingestion had no effect on LMS (13.19 ± 1.12 km·h–1 vs. 13.17 ± 1.08 km·h–1 in CHO and Pl, respectively), nor on [La] and glucose concentration at that speed, or on HR and RPE responses. Pre-test CHO ingestion therefore does not affect LMS or the LMT-estimated anaerobic threshold.

scholarly journals Physiological responses and cycle characteristics during double-poling versus diagonal-stride roller-skiing in junior cross-country skiers

2021 ◽  
Author(s):  
Erik P. Andersson ◽  
Irina Hämberg ◽  
Paulo Cesar Do Nascimento Salvador ◽  
Kerry McGawley
Keyword(s):  
Oxygen Uptake ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Peak Oxygen Uptake ◽  
Submaximal Exercise ◽  
Rating Of Perceived Exertion ◽  
Time To Exhaustion ◽  
Double Poling ◽  
Cross Country

Abstract Purpose This study aimed to compare physiological factors and cycle characteristics during cross-country (XC) roller-skiing at matched inclines and speeds using the double-poling (DP) and diagonal-stride (DS) sub-techniques in junior female and male XC skiers. Methods Twenty-three well-trained junior XC skiers (11 women, 12 men; age 18.2 ± 1.2 yr.) completed two treadmill roller-skiing tests in a randomized order using either DP or DS. The exercise protocols were identical and included a 5 min warm-up, 4 × 5 min submaximal stages, and an incremental test to exhaustion, all performed at a 5° incline. Results No significant three-way interactions were observed between sex, submaximal exercise intensity, and sub-technique. For the pooled sample, higher values were observed for DP versus DS during submaximal exercise for the mean oxygen uptake kinetics response time (33%), energy cost (18%), heart rate (HR) (9%), blood lactate concentration (5.1 versus 2.1 mmol·L−1), rating of perceived exertion (12%), and cycle rate (25%), while cycle length was lower (19%) (all P < 0.001). During the time-to-exhaustion (TTE) test, peak oxygen uptake ($$\dot{V}$$ V ˙ O2peak), peak HR, and peak oxygen pulse were 8%, 2%, and 6% lower, respectively, for DP than DS, with a 29% shorter TTE during DP (pooled data, all P < 0.001). Conclusion In well-trained junior XC skiers, DP was found to exert a greater physiological load than DS during uphill XC roller-skiing at submaximal intensities. During the TTE test, both female and male athletes were able to ski for longer and reached markedly higher $$\dot{V}$$ V ˙ O2peak values when using DS compared to DP.

scholarly journals Peripheral Modulators of the Central Fatigue Development and Their Relationship with Athletic Performance in Jumper Horses

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 743
Author(s):  
Francesca Arfuso ◽  
Claudia Giannetto ◽  
Elisabetta Giudice ◽  
Francesco Fazio ◽  
Michele Panzera ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Athletic Performance ◽  
Lactate Concentration ◽  
Indirect Evidence ◽  
Blood Lactate Concentration ◽  
Central Fatigue ◽  
Serotoninergic System ◽  
Stressful Situation ◽  
Passive Behavior ◽  
Fatigue Development

The current study aimed to investigate whether peripheral modulators of serotoninergic function and neurohumoral factors’ changes in athletic horses during an official jumping competition, and to evaluate their relationship with the physical performance of competing horses. From 7 Italian Saddle mares (6–9 years; mean body weight 440 ± 15 kg), performing the same standardized warm-up and jumping course during an official class, heart rate (HR) was monitored throughout the competition. Rectal temperature (RT) measurement, blood lactate and glucose concentration, serum tryptophan, leucine, valine, the tryptophan/branched-chain amino-acids ratio (Try/BCAAs), dopamine, prolactin, and non-esterified fatty acids (NEFAs) were assessed before the exercise event (T0), at the end of the competition stage (5 min ± 10 s following the cessation of the exercise, TPOST5), and 30 min after the end of competition (TPOST30). Highest HR values were recorded during the course and at the outbound (p < 0.0001); blood lactate concentration and RT increased after exercise with respect to the rest condition (p < 0.0001). Lower leucine and valine levels (p < 0.01), and higher tryptophan, Try/BCAAs ratio, and NEFAs values were found at TPOST5 and TPOST30 with respect to T0 (p < 0.0001). A higher prolactin concentration was found at TPOST5 and TPOST30 compared to T0 (p < 0.0001), whereas dopamine showed decreased values after exercise compared to rest (p < 0.0001). Statistically significant correlations among the peripheral indices of serotoninergic function, neurohumoral factors, and athletic performance parameters were found throughout the monitoring period. The findings provide indirect evidence that the serotoninergic system may be involved in fatigue during jumper exercise under a stressful situation, such as competition, in which, in addition to physical effort, athletic horses exhibit more passive behavior.

scholarly journals Lactate, Heart Rate and Rating of Perceived Exertion Responses to Shorter and Longer Duration CrossFit® Training Sessions

2018 ◽  
Vol 3 (4) ◽  
pp. 60 ◽  
Author(s):  
Ramires Tibana ◽  
Nuno de Sousa ◽  
Jonato Prestes ◽  
Fabrício Voltarelli
Keyword(s):  
Heart Rate ◽  
Perceived Exertion ◽  
Recovery Period ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Cardiovascular Responses ◽  
Cardiovascular Fitness ◽  
Rating Of Perceived Exertion ◽  
Training Experience ◽  
Significant Difference

The aim of this study was to analyze blood lactate concentration (LAC), heart rate (HR), and rating perceived exertion (RPE) during and after shorter and longer duration CrossFit® sessions. Nine men (27.7 ± 3.2 years; 11.3 ± 4.6% body fat percentage and training experience: 41.1 ± 19.6 months) randomly performed two CrossFit® sessions (shorter: ~4 min and longer: 17 min) with a 7-day interval between them. The response of LAC and HR were measured pre, during, immediately after, and 10, 20, and 30 min after the sessions. RPE was measured pre and immediately after sessions. Lactate levels were higher during the recovery of the shorter session as compared with the longer session (shorter: 15.9 ± 2.2 mmol/L/min, longer: 12.6 ± 2.6 mmol/L/min; p = 0.019). There were no significant differences between protocols on HR during (shorter: 176 ± 6 bpm or 91 ± 4% HRmax, longer: 174 ± 3 bpm or 90 ± 3% HRmax, p = 0.387). The LAC was significantly higher throughout the recovery period for both training sessions as compared to pre-exercise. The RPE was increased immediately after both sessions as compared to pre-exercise, while there was no significant difference between them (shorter: 8.7 ± 0.9, longer: 9.6 ± 0.5; p = 0.360). These results demonstrated that both shorter and longer sessions induced elevated cardiovascular responses which met the recommendations for gains in cardiovascular fitness. In addition, both training sessions had a high metabolic and perceptual response, which may not be suitable if performed on consecutive days.

scholarly journals Effects of Adding Small Combat Games to Regular Taekwondo Training on Physiological and Performance Outcomes in Male Young Athletes

2021 ◽  
Vol 12 ◽  
Author(s):  
Ibrahim Ouergui ◽  
Emerson Franchini ◽  
Hamdi Messaoudi ◽  
Hamdi Chtourou ◽  
Anissa Bouassida ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Random Order ◽  
Performance Outcomes ◽  
Rating Of Perceived Exertion ◽  
Control Group ◽  
Metabolic Demand ◽  
Before And After ◽  
Post Hoc

This study investigated the effect of area sizes (4 × 4, 6 × 6, and 8 × 8 m) and effort-pause ratios (free combat vs. 1:2) variation on the physiological and perceptive responses during taekwondo combats (Study 1). In a second study, the effects on physical performance of 8 weeks of small combat-based training added to regular taekwondo training were investigated (Study 2). In random order, 32 male taekwondo athletes performed six (i.e., two effort-to-pause ratios × three area sizes conditions) different 2-min taekwondo combats (Study 1). Thereafter (Study 2), they were randomly assigned to three experimental groups (4 × 4, 6 × 6, and 8 × 8 m) and an active control group (CG). Regarding Study 1, blood lactate concentration [La] before and after each combat, mean heart rate (HRmean) during each combat, and rating of perceived exertion (CR-10) immediately after each combat were assessed. Regarding Study 2, progressive specific taekwondo (PSTT) to estimate maximum oxygen consumption (VO2max), taekwondo-specific agility, and countermovement jump (CMJ) tests were administered before and after 8 weeks of training. Study 1 results showed that 4 × 4 m elicited lower HRmean values compared with 6 × 6 m (d = −0.42 [small], p = 0.030) and free combat induced higher values compared with the 1:2 ratio (d = 1.71 [large], p &lt; 0.001). For [La]post, 4 × 4 m area size induced higher values than 6 × 6 m (d = 0.99 [moderate], p &lt; 0.001) and 8 × 8 m (d = 0.89 [moderate], p &lt; 0.001) and free combat induced higher values than 1:2 ratio (d = 0.69 [moderate], p &lt; 0.001). Higher CR-10 scores were registered after free combat compared with 1:2 ratio (d = 0.44 [small], p = 0.007). For Study 2, VO2max increased after training [F(1, 56) =30.532, p &lt; 0.001; post-hoc: d = 1.27 [large], p &lt; 0.001] with higher values for 4 × 4 m compared with CG (d = 1.15 [moderate], p = 0.009). Agility performance improved after training [F(1, 56) = 4.419, p = 0.04; post-hoc: d = −0.46 [small], p = 0.04] and 4 × 4 m induced lower values in comparison with 6 × 6 m (d = −1.56 [large], p = 0.001) and CG (d = −0.77 [moderate], p = 0.049). No training type influenced CMJ performance. Smaller area size elicited contrasting results in terms of metabolic demand compared with larger sizes (i.e., lower HRmean but higher [La] and CR-10), whereas free combat induced variables' consistently higher values compared with imposed 1:2 ratio (Study 1). Taekwondo training is effective to improve VO2max and agility (Study 2), but small combat training modality should be investigated further.

scholarly journals Does caffeine supplementation alter energy contribution during a work-based ~30 min cycling time-trial?

2020 ◽  
Vol 34 (3) ◽  
pp. 471-481
Author(s):  
Gabriel Barreto ◽  
Rafael Pires da Silva ◽  
Guilherme Yamaguchi ◽  
Luana Farias de Oliveira ◽  
Vitor de Salles Painelli ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Time Trial ◽  
Energy System ◽  
Energy Contribution ◽  
Mean Power ◽  
Double Blind ◽  
Cycling Time Trial ◽  
Cycling Time

Caffeine has been shown to increase anaerobic energy contribution during short-duration cycling time-trials (TT) though no information exists on whether caffeine alters energy contribution during more prolonged, aerobic type TTs. The aim of this study was to determine the effects of caffeine supplementation on longer and predominantly aerobic exercise. Fifteen recreationally-trained male cyclists (age 38±8 y, height 1.76±0.07 m, body mass 72.9±7.7 kg) performed a ~30 min cycling TT following either 6 mg·kg-1BM caffeine (CAF) or placebo (PLA) supplementation, and one control (CON) session without supplementation, in a double- -blind, randomised, counterbalance and cross-over design. Mean power output (MPO) was recorded as the outcome measure. Respiratory values were measured throughout exercise for the determination of energy system contribution. Data were analysed using mixed-models. CAF improved mean MPO compared to CON (P=0.01), and a trend towards an improvement compared to PLA (P=0.07); there was no difference in MPO at any timepoint throughout the exercise between conditions. There was a main effect of Condition (P=0.04) and Time (P<0.0001) on blood lactate concentration, which tended to be higher in CAF vs. both PLA and CON (Condition effect, both P=0.07). Ratings of perceived exertion increased over time (P<0.0001), with no effect of Condition or interaction (both P>0.05). Glycolytic energy contribution was increased in CAF compared to CON and PLA (both P<0.05), but not aerobic or ATP-CP (both P>0.05). CAF improved aerobic TT performance compared to CON, which could be explained by increased glycolytic energy contribution.

scholarly journals Physiological and Competitive Characteristics of Professional Female Futsal Players

2021 ◽  
Vol 21 (1) ◽  
pp. 19-25
Author(s):  
Tommy Apriantono ◽  
Samsul Bahri ◽  
Sri Ihsani Indah ◽  
Bagus Winata
Keyword(s):  
Perceived Exertion ◽  
Lactate Concentration ◽  
Anaerobic Capacity ◽  
Blood Lactate Concentration ◽  
Aerobic Performance ◽  
Anaerobic Performance ◽  
Mean Power ◽  
Significant Difference ◽  
Post Test ◽  
Training Team

The study purpose was to examine the anaerobic and aerobic performance and also determine the influence of the anaerobic performance on specific movements during a match-play.   Materials and methods. A total of 12 Indonesian professional female players from Bandung district female futsal club were recruited and enrolled to participate in this study. They were required to complete one familiarization and two experimental sessions. During the first session (laboratory test), all players performed a treadmill test to ascertain their maximum rate of oxygen consumption (VO2max) and a running-based anaerobic sprint test (RAST) to measure their anaerobic performance. For the second session (on-court test), the participants played a simulated match on the court. A training team of 5 experts carried out an investigation regarding each player’s competitive performance per match. Furthermore, the blood lactate concentration and Rate of Perceived Exertion (RPE) were assessed in the pre- and post-test for both sessions, which were separated by a week to enable the players to recover. Results. The results showed that there was no significant difference between the mean power (MP) and fatigue index (FI) (p = 0.425, p = 0.938, respectively) for anaerobic performance using Analysis of Variance (ANOVA), although, the MP and FI of team C was lower compared to A and B. Furthermore, the total number of failed passes and shot off target of team C was larger compared to B and A (for failed passes = 30 vs 20 vs 25, for shot off target 14 vs 13 vs 8).  Conclusions. The results obtained indicate that there are strong associations between anaerobic capacity and explosive movements (shooting, tackling, heading and passing) among female futsal players.

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