| 1. |
- Björklund, Glenn, 1972-, et al.
(författare)
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Using Bilateral Functional and Anthropometric Tests to Define Symmetry in Cross-Country Skiers
- 2017
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Ingår i: Journal of Human Kinetics. - : Walter de Gruyter GmbH. - 1640-5544 .- 1899-7562. ; 60:1, s. 9-18
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate the symmetry of anthropometry and muscle function in cross-country skiers and their association to vertical jumping power. Twenty cross-country skiers were recruited (21.7 +/- 3.8 yrs, 180.6 +/- 7.6 cm, 73.2 +/- 7.6 kg). Anthropometric data was obtained using an iDXA scan. VO2max was determined using the diagonal stride technique on a ski treadmill. Bilateral functional tests for the upper and lower body were the handgrip and standing heel-rise tests. Vertical jump height and power were assessed with a counter movement jump. Percent asymmetry was calculated using a symmetry index and four absolute symmetry index levels. At a group level the upper body was more asymmetrical with regard to lean muscle mass (p = 0.022, d = 0.17) and functional strength (p = 0.019, d = 0.51) than the lower body. At an individual level the expected frequencies for absolute symmetry level indexes showed the largest deviation from zero for the heel-rise test (chi 2 = 16.97, p = 0.001), while the leg lean mass deviated the least (chi 2 = 0.42, p = 0.517). No relationships were observed between absolute symmetry level indexes of the lower body and counter movement jump performance (p > 0.05). As a group the skiers display a more asymmetrical upper body than lower body regarding muscle mass and strength. Interestingly at the individual level, despite symmetrical lean leg muscle mass the heel-rise test showed the largest asymmetry. This finding indicates a mismatch in muscle function for the lower body.
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| 2. |
- Fransson, Dan, 1980, et al.
(författare)
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Fatigue Responses in Various Muscle Groups in Well-Trained Competitive Male Players after a Simulated Soccer Game
- 2018
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Ingår i: Journal of Human Kinetics. - : Walter de Gruyter GmbH. - 1640-5544 .- 1899-7562. ; 61, s. 85-97
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Tidskriftsartikel (refereegranskat)abstract
- We examined the degree of post-game fatigue and the recovery pattern in various leg and upper-body muscle groups after a simulated soccer game. Well-trained competitive male soccer players (n = 12) participated in the study. The players completed the Copenhagen Soccer Test, a 2 x 45 min simulated soccer protocol, following baseline measures of maximal voluntary contractions of multiple muscle groups and systemic markers of muscle damage and inflammation at 0, 24 and 48 h into recovery. All muscle groups had a strength decrement (p ≤ 0.05) at 0 h post-match with knee flexors (14 ± 3%) and hip abductors (6 ± 1%) demonstrating the largest and smallest impairment. However, 24 h into recovery all individual muscles had recovered. When pooled in specific muscle groups, the trunk muscles and knee joint muscles presented the largest decline 0 h post-match, 11 ± 2% for both, with the performance decrement still persistent (4 ± 1%, p ≤ 0.05) for trunk muscles 24 h into recovery. Large inter-player variations were observed in game-induced fatigue and recovery patterns in the various muscle groups. Markers of muscle damage and inflammation peaked 0 h post-match (myoglobin) and 24 h into recovery (creatine kinase), respectively, but thereafter returned to baseline. Intermittent test performance correlated with creatine kinase activity 24 h after the Copenhagen Soccer Test (r = -0.70; p = 0.02). In conclusion, post-game fatigue is evident in multiple muscle groups with knee flexors showing the greatest performance decrement. Fatigue and recovery patterns vary markedly between muscle groups and players, yet trunk muscles display the slowest recovery.
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| 3. |
- Gago, Paulo, et al.
(författare)
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Post Activation Potentiation of the Plantarflexors: Implications of Knee Angle Variations
- 2017
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Ingår i: Journal of Human Kinetics. - : Walter de Gruyter GmbH. - 1640-5544 .- 1899-7562. ; 57, s. 29-38
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Tidskriftsartikel (refereegranskat)abstract
- Flexing the knee to isolate the single joint soleus from the biarticular gastrocnemius is a strategy forinvestigating individual plantarflexor's post activation potentiation (PAP). We investigated the implications of testingplantarflexor PAP at different knee angles and provided indirect quantification of the contribution of gastrocnemiuspotentiation to the overall plantarflexor enhancements post conditioning. Plantarflexor supramaximal twitches weremeasured in ten male power athletes before and after a maximal isometric plantarflexion (MVIC) at both flexed andextended knee angles. Mean torque and soleus (SOLRMS) and medial gastrocnemius (MGRMS) activity were measuredduring the MVIC. The mean torque and MGRMS of the MVIC were lower (by 33.9 and 42.4%, respectively) in the flexedcompared to the extended position, with no significant difference in SOLRMS. After the MVIC, twitch peak torque (PT)and the rate of torque development (RTR) potentiated significantly more (by 17.4 and 14.7% respectively) in theextended as compared to the flexed knee position, but only immediately (5 s) after the MVIC. No significant differenceswere found in the twitch rate of torque development (RTD) potentiation between positions. It was concluded that kneejoint configuration should be taken into consideration when comparing studies of plantarflexor PAP. Furthermore,results reflect a rather brief contribution of the gastrocnemius potentiation to the overall plantarflexor twitchenhancements.
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| 4. |
- Lännerström, Johan, et al.
(författare)
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Effects of Plyometric Training on Soft and Hard Surfaces for Improving Running Economy.
- 2021
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Ingår i: Journal of Human Kinetics. - : Sciendo. - 1640-5544 .- 1899-7562. ; 79:1, s. 187-196
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Tidskriftsartikel (refereegranskat)abstract
- The present study investigated the effects of plyometric jump training on hard and soft surfaces on running economy (RE), maximal oxygen uptake (VO2max), running performance and the rate of force development in orienteers. Nineteen orienteers (11 women and 8 men, body mass 61.1 ± 7.3 kg, age 21 ± 5.8 yrs) were randomly stratified based on sex, age, VO2max and RE to plyometric jumping training (8 sessions over 4 weeks) on either a hard or a soft surface. RE, VO2max and running performance were assessed on a treadmill and outdoor on- and off-trail loops. Moreover, ground reaction forces and force development were assessed during a one leg drop-jump test. The training intervention led to an overall 2-7% improvement in treadmill and off-trail RE, independent of the jumping surface and running velocity assessed. These improvements were not explained by force development during drop jump tests, which remained unchanged following the intervention. The changes in time-trial performance were associated with changes in RE. Plyometric training improved RE with no difference between the hard or the soft training surface and improved RE was also independent of the running speed assessed. Furthermore, improved running performance was associated with changes in RE after the intervention.
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| 5. |
- Mohr, Magni, 1973, et al.
(författare)
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Comparison between two types of anaerobic speed endurance training in competitive soccer players
- 2016
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Ingår i: Journal of Human Kinetics. - : Walter de Gruyter GmbH. - 1640-5544 .- 1899-7562. ; 50:2, s. 183-192
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the present study was to examine the effects of additional in-season speed endurance production versus speed endurance maintenance training regimes on performance in competitive male soccer players. In a randomised controlled trial 18 male sub-elite players were exposed to additional speed endurance production (SEP) or speed endurance maintenance (SEM) training (two additional sessions/wk for 4 weeks) during the competitive season. Players performed the Yo-Yo intermittent recovery level 2 test (YYIR2) and a repeated sprint test (RST) pre- and post-intervention. Yo-Yo IR2 performance increased (p<0.001) by 50 ± 8% and 26 ± 5% in SEP and SEM, respectively, with greater (p=0.03) improvement in SEP. RST performance improved by 2.1 ± 0.3% and 1.3 ± 0.4% in SEP and SEM, respectively, while the RST fatigue index decreased (4.4 ± 0.8 to 3.4 ± 0.5%; p<0.04) in SEP only. Peak and average speed during training were higher (p<0.001) in SEP than in SEM (24.5 ± 0.3 vs 19.2 ± 0.3 and 15.5 ± 0.1 km·h-1 vs 9.4 ± 0.1 km·h-1). Additional in-season anaerobic speed endurance production and maintenance training improves high-intensity exercise performance in competitive soccer players with superior effects of speed endurance production training. © Editorial Committee of Journal of Human Kinetics 2016.
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| 6. |
- Padrón-Cabo, Alexis, et al.
(författare)
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Effects of Training with an Agility Ladder on Sprint, Agility, and Dribbling Performance in Youth Soccer Players
- 2020
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Ingår i: Journal of Human Kinetics. - : Sciendo. - 1640-5544 .- 1899-7562. ; 73:1, s. 219-228
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to examine the effects of coordination training using an agility ladder compared with a control group on physical fitness and technical performance in youth soccer players. Eighteen male youth soccer players (age: 12.2 ± 0.4 years; body height: 158.3 ± 10.8 cm; body mass: 45.0 ± 8.0 kg) were randomly assigned to an agility ladder group (n = 10) or a control group (n = 8). The intervention program was carried out three times a week over six weeks. Before and after the training period, the 10 m sprint, 20 m sprint, dribbling speed test, agility test, and slalom dribbling test performances were assessed. Within-group analysis showed significant improvements (p < 0.005) in 10 m and 20 m sprint performance from the pre- to the post-test for the agility ladder group (-2.39% and -2.10%) and the control group (-2.54% and -1.44%). No significant differences (p > 0.005) were found from the pre- to the post-test in the dribbling speed test, agility test, slalom dribbling test, and skill index. In the between-group analysis, there were no differences between the agility ladder group and the control group in any variable. In conclusion, the findings of this study suggest coordination training with an agility ladder does not seem to be effective to improve physical fitness and dribbling. Therefore, this information could be beneficial to players and coaches for programming tasks during soccer training sessions.
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| 7. |
- Pagaduan, Jeffrey, et al.
(författare)
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A Meta-Analysis on the Effect of Complex Training on Vertical Jump Performance
- 2020
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Ingår i: Journal of Human Kinetics. - : Sciendo. - 1640-5544 .- 1899-7562. ; 71:1, s. 255-265
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Tidskriftsartikel (refereegranskat)abstract
- Complex training (CT) is a strength training intervention performed by completing all the sets of a resistanceexercise followed by a series of high-velocity/plyometric exercise/s. The purpose of this novel study was to conduct a metaanalysison the effect of CT on vertical jump (VJ) performance. Five electronic databases were searched using terms relatedto CT and the VJ. Studies needed to include randomized trials comparing CT with traditional resistance training(RT)/plyometric training (PLYO)/control (CON) lasting ≥ 4 weeks and the VJ as a dependent variable. Seven studiesqualified for the meta-analysis with two studies differentiating VJ performance from CT and RT, two studies comparingVJ performance of CT and PLYO, and two studies establishing the difference in VJ performance between CT and CON.Results indicated similar improvement in VJ performance from CT and RT (p = 0.88). On the other hand, greater VJperformance in CT than PLYO was identified (ES = 0.86; 95% CI 0.24, 1.47; p = 0.01). CT also showed significantlygreater enhancement in VJ compared to CON (ES = 1.14; 95% CI 0.60, 1.68; p < 0.01). In conclusion, CT can serve asalternative training from RT in improving VJ performance. On the other hand, CT is a better option in VJ enhancementthan PLYO and CON.
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| 8. |
- Pagaduan, Jeffrey C., et al.
(författare)
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Effect of various warm-up protocols on jump performance in college football players
- 2012
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Ingår i: Journal of Human Kinetics. - : Sciendo. - 1640-5544 .- 1899-7562. ; 35:1, s. 127-132
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to identify the effects of warm-up strategies on countermovement jump performance. Twenty-nine male college football players (age: 19.4 ± 1.1 years; body height: 179.0 ± 5.1 cm; body mass: 73.1 ± 8.0 kg; % body fat: 11.1 ± 2.7) from the Tuzla University underwent a control (no warm-up) and different warm-up conditions: 1. general warm-up; 2. general warm-up with dynamic stretching; 3. general warm-up, dynamic stretching and passive stretching; 4. passive static stretching; 5. passive static stretching and general warm-up; and, 6. passive static stretching, general warm-up and dynamic stretching. Countermovement jump performance was measured after each intervention or control. Results from one way repeated measures ANOVA revealed a significant difference on warm-up strategies at F (4.07, 113.86) = 69.56, p < 0.001, eta squared = 0.72. Bonferonni post hoc revealed that a general warm-up and a general warm-up with dynamic stretching posted the greatest gains among all interventions. On the other hand, no warm-up and passive static stretching displayed the least results in countermovement jump performance. In conclusion, countermovement jump performance preceded by a general warmup or a general warm-up with dynamic stretching posted superior gains in countermovement jump performance.
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| 9. |
- Papanikolaou, Konstantinos, et al.
(författare)
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The Yo-Yo intermittent endurance level 2 test: reliability of performance scores, physiological responses and overload characteristics in competitive soccer, basketball and volleyball players
- 2019
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Ingår i: Journal of Human Kinetics. - : Termedia Sp. z.o.o.. - 1640-5544 .- 1899-7562. ; 67:1, s. 223-233
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Tidskriftsartikel (refereegranskat)abstract
- 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 assessment of performance, heart rate, running speed, accelerations, decelerations and body load using GPS instrumentation. The intra-class correlation coefficient index, confidence intervals and coefficients of variation were calculated to assess the reliability of the test. Intra-class correlation coefficients for test-retest trials in the total sample ranged from large to nearly perfect (total distance: 0.896; mean speed: 0.535; maximum speed: 0.715; mean HR: 0.876; maximum HR: 0.866; body load: 0.865). The coefficients of variation for distance, mean speed, HR response, as well as acceleration and deceleration scores for test-retest trials ranged from 1.2 to 12.5% with no differences observed among particular sport disciplines. The CV for shuttles performed ranged from 4.4 to 5.5% in all sports. Similar results were obtained for the three different categories of players tested. These results suggest that the Yo-Yo IE2 test appears to be a reliable alternative for evaluating the ability to perform intermittent high-intensity running in different outdoor and indoor team sports. Players may need one or two familiarization tests to ensure valid assessment of intermittent endurance capacity. It appears that the Yo-Yo IE2 test incorporates accelerations and decelerations in a consistent and reproducible fashion.
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| 10. |
- Pinilla Arbex, Javier, et al.
(författare)
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Cognitive Development and Decision Making in Basketball : A Comparison between Male Players with and without Intellectual Impairment and across Different Age-Groups
- 2024
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Ingår i: Journal of Human Kinetics. - : Termedia. - 1640-5544 .- 1899-7562. ; 93, s. 231-243
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the role of age and intellectual impairment (II) in decision-making in basketball. The current study investigated differences in decision making between equally well-trained adult basketball male players with intellectual impairment (players with II) (n = 93), adults without II (senior) (n = 44) and youth basketball players (under-14, n = 31; under-16, n = 25; under-18, n = 30). A computer test was developed composed by 20 photographs displaying various basketball game-situations, and participants had to decide as fast as possible what the player in ball possession should do: dribble, pass or shoot. Decision time and accuracy were recorded for every situation. Players with II had slower decision time (3.8 ± 1.8 s vs. 1.5 ± 0.5 s, p < 0.001) and less decision-making accuracy (15.7 ± 2.8 correct decisions vs. 17.9 ± 1.2 correct decisions, p < 0.001) compared to senior players without II. Discriminant analysis with speed and accuracy as independent variables classified 91.2% (CCA = 0.769) of the players correctly into their group: players with II or players without II. A Spearman correlation revealed that age correlated significantly (p < 0.001) with the number of correct decisions (rs = 0.269) and mean decision time (rs = −0.331). Our findings support that decision making in basketball develops with age and experience, but is significantly deteriorated in experienced adult players who have II. Decision-making should be considered as an important eligibility criterion to participate in competitive basketball events for male players with II.
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| 11. |
- Pojskić, Haris, 1978-, et al.
(författare)
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Acute Effects of Loaded and Unloaded Whole-Body Vibration on Vertical Jump Performance in Karate Practitioners
- 2024
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Ingår i: Journal of Human Kinetics. - : Sciendo. - 1640-5544 .- 1899-7562. ; 92, s. 203-212
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the acute effects of different whole-body vibration (WBV) interventions on the jump height ofhighly trained karate practitioners. Fifteen male karate club athletes (age: 20.0 ± 3.8 years; stature: 177.3 ± 4.7 cm; bodymass: 76.9 ± 11.2 kg; % body fat: 9.2 ± 4.3) performed six randomized interventions: [a] static half-squat (SHS); [b] SHSwith external loads at 30% of the body weight (SHS + 30%BW); [c] WBV at frequency (f) 25 Hz, and 2 mm amplitude(A) (WBV 25/2); [d] WBV 25/2 with external loads of 30% of the body weight (WBV 25/2 + 30% BW); [e] WBV at f =50 Hz, and A = 4 mm (WBV 50/4), and [f] WBV 50/4 with external loads of 30% of the body weight (WBV 50/4 + 30%BW). Each intervention was performed for 5 sets at 60 s/set, with a rest interval of 30 s between sets. Countermovementjump (CMJ) data were collected at 2, 4, 6, 8 and 10 min after each preconditioning intervention. Two-way repeatedmeasures ANOVA revealed a non-significant main effect of intervention [F(5, 10) = 1.44, η2 = 0.42, p = 0.29)] and asignificant main effect of the rest interval [F(4, 11) = 3.51, η2 = 0.56, p = 0.04)] on CMJ height. A rest interval of 4 minresulted in significantly higher CMJ values than a rest interval of 2 min (p = 0.031). In conclusion, utilizing a 4-min restinterval irrespective of the intervention schemes may have potential for enhancing jumping performance among highlytrained karate athletes.
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| 12. |
- Pojskić, Haris, 1978-, et al.
(författare)
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Positional Role Differences in the Aerobic and Anaerobic Power of Elite Basketball Players
- 2015
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Ingår i: Journal of Human Kinetics. - : De Gruyter Open. - 1640-5544 .- 1899-7562. ; 49:1, s. 219-227
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to compare the aerobic and anaerobic power and capacity of elite male basketball players who played multiple positions. Fifty-five healthy players were divided into the following three different subsamples according to their positional role: guards (n = 22), forwards (n = 19) and centers (n = 14). The following three tests were applied to estimate their aerobic and anaerobic power and capacities: the countermovement jump (CMJ), a multistage shuttle run test and the Running-based Anaerobic Sprint Test (RAST). The obtained data were used to calculate the players' aerobic and anaerobic power and capacities. To determine the possible differences between the subjects considering their different positions on the court, one-way analysis of variance (ANOVA) with the Bonferroni post-hoc test for multiple comparisons was used. The results showed that there was a significant difference between the different groups of players in eleven out of sixteen measured variables. Guards and forwards exhibited greater aerobic and relative values of anaerobic power, allowing shorter recovery times and the ability to repeat high intensity, basketball-specific activities. Centers presented greater values of absolute anaerobic power and capacities, permitting greater force production during discrete tasks. Coaches can use these data to create more individualized strength and conditioning programs for different positional roles.
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| 13. |
- Schulte, Stefanie, et al.
(författare)
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Serum Concentrations of S100B are not Affected by Cycling to Exhaustion With or Without Vibration
- 2011
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Ingår i: Journal of Human Kinetics. - : Termedia Sp. z.o.o.. - 1640-5544 .- 1899-7562. ; 30:1, s. 67-78
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Tidskriftsartikel (refereegranskat)abstract
- The calcium-binding protein S100B is produced primarily by astrocytes and exerts concentration-dependentparacrine and autocrine effects on neurons and glia. The numerous findings of a correlation between S100B andtraumatic brain injury (TBI) have resulted in the employment of this protein as a clinical biomarker for such injury.Our present aim was to determine whether cycling with (V) or without (NV) vibration alters serum concentrations ofS100B. Twelve healthy, male non-smokers (age: 25.3±1.6 yrs, body mass: 74.2±5.9 kg, body height: 181.0±3.7 cm,VO2peak: 56.9±5.1 ml·min-1·kg-1(means ± SD)) completed in random order two separate trials to exhaustion on avibrating bicycle (amplitude 4 mm and frequency 20 Hz) connected to an ergometer. The initial workload of 100 W waselevated by 50 W every 5 min and the mean maximal period of exercise was 25:27±1:30 min. The S100B in venousblood taken at rest, immediately after the test, and 30, 60 and 240 min post-exercise exhibited no significant differences(p>0.05), suggesting that cycling with and without vibration does not influence this parameter.
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| 14. |
- Zinner, C., et al.
(författare)
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Cardiorespiratory, Metabolic and Perceived Responses to Electrical Stimulation of Upper-Body Muscles while Performing Arm Cycling
- 2021
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Ingår i: Journal of Human Kinetics. - : Termedia Sp. z.o.o.. - 1640-5544 .- 1899-7562. ; 77:1, s. 117-123
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Tidskriftsartikel (refereegranskat)abstract
- This study was designed to assess systemic cardio-respiratory, metabolic and perceived responses to incremental arm cycling with concurrent electrical myostimulation (EMS). Eleven participants (24 ± 3 yrs; 182 ± 10 cm; 86 ± 16.8 kg) performed two incremental tests involving arm cycling until volitional exhaustion was reached with and without EMS of upper-body muscles. The peak power output was 10.1% lower during arm cycling with (128 ± 30 W) than without EMS (141 ± 25 W, p = 0.01; d = 0.47). In addition, the heart rate (2-9%), oxygen uptake (7-15%), blood lactate concentration (8-46%) and ratings of perceived exertion (4-14%) while performing submaximal arm cycling with EMS were all higher with than without EMS (all p < 0.05). Upon exhaustion, the heart rate, oxygen uptake, lactate concentration, and ratings of perceived exertion did not differ between the two conditions (all p > 0.05). In conclusion, arm cycling with EMS induced more pronounced cardio-respiratory, metabolic and perceived responses, especially during submaximal arm cycling. This form of exercise with stimulation might be beneficial for a variety of athletes competing in sports involving considerable generation of work by the upper body (e.g., kayaking, cross-country skiing, swimming, rowing and various parasports).
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