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This study aims to examine repeated sprint performances of young soccer players in the same age category according to competition level and playing positions. 67 young soccer players in the U16 age category and from 4 different teams competing in two different competition levels participated voluntarily in this study. The participants performed the Bangsbo Sprint Test adapted by Wragg (7×34,2 m with 25-second recovery) to determine repeated sprint performance. The test variables were best sprint time, mean sprint time, and the fatigue index. The best sprint time and mean sprint time results varied according to competition level (p=0,05) but the fatigue index did not differentiate according to competition level (p=0,05). It is also determined that at a high competition level players have revealed better-repeated sprint performance. When examined the data in terms of game position, best sprint time and mean time values have varied (p=0,05) but the fatigue index did not have significant differences (p=0,05). Considering the data according to game positions, forwards, full-backs and wingers showed higher performance than central midfielders, central defenders, and goalkeepers. Consequently, our results suggest that performance in repeated-sprint the best sprint values and mean sprint values belonging to repeated performances of youth players from the same age category differ according to competition levels and game positions, whereas the fatigue index does not differ. [ABSTRACT FROM AUTHOR]

Objective: No study has analyzed the effects of caffeine ingestion on performance during a multidirectional high-intensity intermittent exercise. Thus, we aimed to investigate the effects of caffeine ingestion during a novel repeated agility test in futsal athletes. Methods: Using a double-blind, counterbalanced, and repeated-measures design, ten athletes (mass 71.2 ± 8.7 kg, height 1.77 ± 0.05m, body mass index 22.7 ± 1.9 km/m², body fat percentage 10.2 ± 3.7%) performed a novel repeated-bout agility test 60 min after ingesting 6mg. kg-1 of caffeine or cellulose (placebo). Results: Performance time decreased progressively throughout the trial in both conditions (P=0.01; ηp 2=0.66), with a significant interaction effect (P=0.01; ηp ²=0.35) showing a potential beneficial effect of caffeine at the beginning, followed by a decrease at the end of the test. Furthermore, magnitude of decrease in performance was more pronounced in caffeine (-9.0 ± 5.7%) compared with placebo (-4.7 ± 3.9%, P=0.01; d=0.88). Interestingly, magnitudebased inferences revealed a possible benefit (70%) of caffeine at the beginning, followed by likely (93%) to very likely (96%) impairments in performance during the last third of the test. Heart rate and rating of perceived effort increased in both conditions over the time (P<0.05), with similar values between experimental conditions (P>0.05). Conclusion: Caffeine seems to have a potential beneficial effect at the beginning, with an impaired performance during the final third of a new multidirectional high-intensity intermittent exercise in futsal athletes. [ABSTRACT FROM AUTHOR]

Increased fatigue may be observed during a soccer match, with a reduction of the high intensity activities owing to physical demands. These actions lead to a decline in players' performance. The aim of the study was to analyze the acute effects of induced fatigue on passing ability in elite U-19 soccer players. Twenty-three elite U-19 soccer players (17.9 ± 0.7 years; weight 69.7 ± 8.1 kg; height 177.2 ± 7.6 cm) performed the Loughborough Soccer Passing Test (LSPT) to evaluate passing ability: control, dribbling, accuracy and decision making. Repeated sprint ability (RSA) was used to induce fatigue, 12 x 30 m sprints followed by 30 s recovery time. Heart rate (HR), Borg's rating of perceived exertion (RPE), time in 5 m and 30 m, sprint decrement (Sdec) and the fatigue index (FI) was collected. Student's t test was applied to compare the difference between pre-test and post-test. Differences were interpreted using Cohen's d effect size. Fatigue led to a significant increase in the number of penalties in the LSPT (p < 0.001; d = 0.54) and in total time to perform the test (p = 0.001; d = 0.37). Of the different types of error, passing accuracy was the ability that declined most (p = 0.010 d = 0.72). Ball control was also affected, but to a lesser extent (p = 0.030; d = 0.39). The results shown that passing ability was affected by fatigue in elite U-19 soccer players. This study provides detailed information for football coaches and physical trainers on the effects of fatigue on passing ability, describing the decline in performance of this specific ability in soccer. [ABSTRACT FROM AUTHOR]

The main goal was to determine anaerobic and aerobic improvement of young soccer players after six-week high volume (HVT) or small sided games (SSG) training intervention. One hundred and one highly trained youth soccer players (16.2 ± 1.3 years) were divided into SSG (n = 51) and HVT groups (n = 50) and according to age into an under sixteen subgroup (U16), under seventeen subgroup (U17), and under nineteen subgroup (U19). The performance was assessed by Yo-Yo intermittent test, Repeated sprint ability test (RSA), and K-test before and after both training interventions. For U16 the SSG group recorded significant improvements in the K-test (0.64 ± 0.56 s; p = .04) and RSA (0.15 ± 0.43 s; p = .01). For U19 the SSG group recorded the same improvements, in the K-test (0.43 ± 0.57 s; p = .007), RSA (0.21 ± 0.22 s; p = .048), and Yo-Yo test (127.25 ± 17.87; p = .049). HVT improved aerobic performance when the Yo-Yo test was significantly better after intervention at U17 (199.00 ± 111.83 m; p = .030), U19 (88.40 ± 66.38 m; p = .049). In total, the HVT group spent 621 min (56.45 ± 5.01 min) of aerobic training and the Small sided game group spent 291 min (26.45 ± 8.61 min) of small sided games focused on aerobic performance. This study showed that both SSG and HVT training interventions were effective for aerobic improvement for the U19 category, but not for younger players. SSG was identified to be more appropriate to fitness development of soccer players.

Repeated sprint training in hypoxia (RSH) represents an innovative method in the process of development and improvement of physical performance among athletes. However, there is less scientific data on this topic. The purpose of this systematic review was to investigate the effect of RSH method on motor abilities and performance among athletes, obtain new information, and expand the already known conclusions. The data search was performed of 4 electronic databases for the years 2000-2021 May as follows: Google Scholar, PubMed, Web of Science, and ResearchGate. This search with English language restriction was made by using the following terms, individually/combination: "repeated sprint ability", "hypoxia", "effects", "physical performance", "VO2max" 844 studies were indentified, and 14 studies were selected (11 male studies, 1 female study, 2 both sexes). Results of this systematic review, a total sample size of 347 athletes (40 females and 307 males, aged 15.3 ± 0.5 - 35 ± 7 years), showed that RSH was an effective training method in improving all monitored variables (i.e. RSAmax, VO2max). However, it should be noted that major improvements were observed mainly in repeated sprint ability (RSA) tests, and less in aerobic tests (i.e. Wingate and Yo-Yo). In conclusion, based on current scientific studies, RSH is more effective method to improve the physical performance among athletes compared to repeated sprint training in normoxia (RSN). This study suggested that the RSH has a positive effect on the monitored variables in physical performance tests especially related to RSA. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the effects of a short-term (six weeks) preseason strength and jumping exercises distribution program on amateur adult soccer player's indicators of physical fitness. Twenty male athletes (age 20.1±1.6 years) were randomly divided into two groups that completed a volumeequated training program differing only in exercises distribution: a group that completed three weeks of strength followed by three weeks of plyometric training (TT; n=10) and a group that completed six weeks of combined strength and plyometric drills (S+P; n=10). Athletes completed a triple hop test with the dominant (HOPd) and non-dominant leg (HOPnd), a 15 meters sprint, a change of direction speed (CODS) test (i.e. T test), and a 6×30 meters repeated sprint with change of direction for the best (RSCODb) and mean velocity (RSCODm), and the percentage of decrement (%Dec) in sprint time. Moreover, athletes performed a squat test for maximal power. Both strength and jumping training programs were performed two times per week, equated for exercises, frequency, volume, and intensity per session. The TT group completed the strength training volume during the first three weeks, and the plyometric training volume in the last three weeks, while the S+P combined strength and plyometric training during the six weeks. A 2 (group) × 2 (time: pre, post) ANOVA with repeated measures was used for statistical analysis. Analyses revealed significant improvements for the TT and S+P (HOPd: ES=0.91, 10.28 and 16.69%, respectively; HOPnd: ES=0.86, 11.49 and 14.71%, respectively; RSCODb: ES=0.84, 9.23 and 8.34%, respectively; RSCODm: ES=0.89, 8.56 and 7.51%, respectively). In the post-test there were no significant differences between the groups in any variable analyzed. In conclusion, both training approaches were equally effective at improving jumping and repeated sprinting ability. However, only after the S+P training approach a significant improvement in CODS was observed, with more substantial changes in maximal sprinting speed. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the biceps femoris long head (BFlh) architecture between football players with (twelve) and without (twenty) history of BFlh injury before and after a repeated sprint task. Fascicle length (FL), pennation angle (PA) and muscle thickness (MT) were assessed at rest and in the active condition before and after the repeated sprint protocol. Athletes with previous BFlh injury showed shorter FL at rest (p = 0.014; η2p = 0.196) and active state (p < 0.001; η2p = 0.413), and greater PA at rest (p = 0.002; η2p = 0.307) and active state (p < 0.001; η2p = 0.368) before and after the task. Intra-individual comparisons showed that injured limbs have shorter FL at rest (p = 0.012; η2p = 0.519) and in the active state (p = 0.039; η2p = 0.332), and greater PA in passive (p < 0.001; η2p = 0.732) and active conditions (p = 0.018; η2p = 0.412), when compared with contralateral limbs. Injured players, at rest and in the active condition, display shorter BFlh FL and greater PA than contralateral and healthy controls after repeated sprints. Moreover, the BFlh of injured players presented a different architectural response to the protocol compared with the healthy controls.

The aim of this investigation was to determine age-related trends for anthropometric and physical variables in elite young soccer players. For this purpose, a total of 114 young male soccer players from a high-performance soccer academy participated in this investigation. Anthropometric and physical variables (countermovement jump, 6×40 m shuttle run test, 2×11 m slalom test with the ball) were determined. Results. Body height (U15U20; p

The main goal was to determine anaerobic and aerobic improvement of young soccer players after six-week high volume (HVT) or small sided games (SSG) training intervention. One hundred and one highly trained youth soccer players (16.2 ± 1.3 years) were divided into SSG (n = 51) and HVT groups (n = 50) and according to age into an under sixteen subgroup (U16), under seventeen subgroup (U17), and under nineteen subgroup (U19). The performance was assessed by Yo-Yo intermittent test, Repeated sprint ability test (RSA), and K-test before and after both training interventions. For U16 the SSG group recorded significant improvements in the K-test (0.64 ± 0.56 s; p = .04) and RSA (0.15 ± 0.43 s; p = .01). For U19 the SSG group recorded the same improvements, in the K-test (0.43 ± 0.57 s; p = .007), RSA (0.21 ± 0.22 s; p = .048), and Yo-Yo test (127.25 ± 17.87; p = .049). HVT improved aerobic performance when the Yo-Yo test was significantly better after intervention at U17 (199.00 ± 111.83 m; p = .030), U19 (88.40 ± 66.38 m; p = .049). In total, the HVT group spent 621 min (56.45 ± 5.01 min) of aerobic training and the Small sided game group spent 291 min (26.45 ± 8.61 min) of small sided games focused on aerobic performance. This study showed that both SSG and HVT training interventions were effective for aerobic improvement for the U19 category, but not for younger players. SSG was identified to be more appropriate to fitness development of soccer players. [ABSTRACT FROM AUTHOR]

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Listening to music during active recovery between exercise bouts has been found to help maintain high levels of exercise performance; however, the effect of listening to music alone with no exercise while resting passively has not been elucidated. We examined whether listening to music during static (passive) recovery affects subsequent repeated sprint performances and/or psychological and physiological responses in healthy young males. Twelve healthy young male athletes completed two consecutive sets of 7 × 7 second maximal cycling sprints with a 30-second rest interval between the sprints. During a 15-minute interval between the sets, the participants rested passively while listening to fast-tempo (Fast, 130 bpm), slow-tempo (Slow, 70 bpm) music, or no music (Con). We assessed affective valence and arousal using the Affect Grid. The valence and arousal scores immediately after listening to fast-tempo music were significantly higher than those in the no music condition. Mean and peak power outputs during the second set after listening to fast-tempo music were significantly higher compared to those after the Slow and Con conditions (both adjusted p <.05). Moreover, the changes in exercise performances between the first and second set were significantly associated with changes in the arousal score induced by the music conditions, but not with changes in the valence score. These results suggested that listening to fast-tempo songs during passive recovery between the exercises improved subsequent repeated sprint cycling performance in physically active males. This type of rapid exercise recovery might be useful for competitive athletes, such as judo, track and fields, and swimming races. [ABSTRACT FROM AUTHOR]

PurposeThis study aimed to examine the effect of applying BFR during rest periods of repeated cycling sprints on muscle oxygenation.MethodsSeven active males performed 5 × 10-s maximal pedaling efforts with 40-s passive rest, with or without BFR application during rest period. BFR was applied for 30 s between sprints (between 5 and 35 s into rest) through a pneumatic pressure cuff inflated at 140 mmHg. Vastus lateralis muscle oxygenation was monitored using near-infrared spectroscopy. In addition, blood lactate concentration and heart rate were also evaluated.ResultsThe BFR trial showed significantly lower oxyhemoglobin (oxy-Hb) and tissue saturation (StO2) levels than the CON trial (P < 0.05). However, power output and blood lactate concentration did not significantly differ between the two trials (P > 0.05).ConclusionApplying BFR during rest periods of repeated cycling sprints decreased muscle oxygenation of active musculature, without interfering with power output during sprints.

Purpose: This study aimed to examine the effect of applying BFR during rest periods of repeated cycling sprints on muscle oxygenation. Methods: Seven active males performed 5 × 10-s maximal pedaling efforts with 40-s passive rest, with or without BFR application during rest period. BFR was applied for 30 s between sprints (between 5 and 35 s into rest) through a pneumatic pressure cuff inflated at 140 mmHg. Vastus lateralis muscle oxygenation was monitored using near-infrared spectroscopy. In addition, blood lactate concentration and heart rate were also evaluated. Results: The BFR trial showed significantly lower oxyhemoglobin (oxy-Hb) and tissue saturation (StO2) levels than the CON trial (P < 0.05). However, power output and blood lactate concentration did not significantly differ between the two trials (P > 0.05). Conclusion: Applying BFR during rest periods of repeated cycling sprints decreased muscle oxygenation of active musculature, without interfering with power output during sprints. [ABSTRACT FROM AUTHOR]

Purpose: To assess the effects of a taper strategy on neuromuscular and metabolic fitness in team sport athletes, through a systematic review and meta-analysis. Method: To be included in this meta-analysis, studies had to involve competitive team sport athletes and a tapering intervention providing details about the procedures used to decrease the training load, as well as competition or field-based criterion performance and all necessary data to calculate effect sizes. Four databases were searched according to these criteria, which led to the identification of 895 potential studies and the subsequent inclusion of 14 articles. Independent variables were training intensity, volume and frequency, as well as the pattern of taper and its duration. The dependent variable was performance obtained in various neuromuscular and metabolic tests. Results: There was limited evidence of a moderate taper-induced improvement in repeated sprint ability (Standardized Mean Difference (SMD) (95%IC;I2) = 0.41 (0.26-0.55;0%)) and moderate evidence of a moderate increase in maximal power (SMD (95%IC;I2) = 0.44 (0.32-0.56;15%)), change of direction speed (SMD (95%IC;I2) = 0.38 (0.15-0.60;28%)) and maximal oxygen uptake (SMD (95%IC;I2) = 0.76 (0.43-1.09;37%)). Conclusion: Tapering is an effective training strategy to improve maximal power, maximal oxygen uptake, repeated sprint ability and change of direction speed in team sports. However, the literature lacks studies using various tapering strategies to compare their effectiveness and make evidence-based recommendations. Future original studies should focus on this major issue. [ABSTRACT FROM AUTHOR]

The aims of this study were (1) to assess the running activities of adolescent tennis players during match play with respect to velocity, acceleration, and deceleration; (2) to characterize changes in these activities during the course of a match; and (3) to identify potential differences between winners and losers. Twenty well-trained adolescent male athletes (13 ± 1 y) played one simulated match each (giving a total of 10 matches), during which distances covered at different velocity categories (0 to < 1, 1 to < 2, 2 to < 3, 3 to < 4, and ≥ 4 m•s-1) and number of running activities involving high velocity (≥ 3 m•s-1), acceleration (≥ 2 m•s-2), and deceleration (≤ -2 m•s-2) were monitored using a global positioning system (10 Hz). Heart rate was also assessed. The total match time, total distance covered, peak velocity, and mean heart rate were 81.2 ± 14.6 min, 3362 ± 869 m, 4.4 ± 0.8 m•s-1, and 159 ± 12 beats•min-1, respectively. Running activities involving high acceleration (0.6 ± 0.2 n•min-1) or deceleration (0.6 ± 0.2 n•min-1) were three times as frequent as those involving high velocity (0.2 ± 0.1 n•min-1). No change in the pattern of running activities (P ≥ .13, d ≤ 0.39) and no differences between winners and losers (P ≥ .22, d ≤ 0.53) were evident during match play. We conclude that training of well-trained adolescent male tennis players need not focus on further development of their running abilities, since this physical component of multifactorial tennis performance does not change during the course of a match and does not differ between the winners and losers. [ABSTRACT FROM AUTHOR]

PurposeTo examine physiological and technical responses to repeated-sprint training in normobaric hypoxia at ∼3,000 m (RSH, n = 11) or in normoxia (RSN, n = 11) compared to a control group (CON, n = 8) in well-trained tennis players. Participants were 28.8 ± 5.9 years old without any previous experience of training in hypoxia.MethodsIn addition to maintaining their usual training (CON), both RSH and RSN groups completed five tennis specific repeated-shuttle sprint sessions (4 × 5 × ∼8 s maximal sprints with ∼22 s passive recovery and ∼5 min rest between sets) over 12 days. Before (Pre), the week after (Post-1) and 3 weeks after Post-1 (Post-2), physical/technical performance during Test to Exhaustion Specific to Tennis (TEST), repeated-sprint ability (RSA) (8 × ∼20 m shuttle runs—departing every 20 s) and heart rate variability (HRV) were assessed.ResultsFrom Pre to Post-1 and Post-2, RSH improved TEST time to exhaustion (+18.2 and +17.3%; both P < 0.001), while the “onset of blood lactate accumulation” at 4 mmol L–1 occurred at later stages (+24.4 and +19.8%, both P < 0.01). At the same time points, ball accuracy at 100% V̇O2max increased in RSH only (+38.2%, P = 0.003 and +40.9%, P = 0.007). Markers of TEST performance did not change for both RSN and CON. Compared to Pre, RSA total time increased significantly at Post-1 and Post-2 (−1.9 and −2.5%, P < 0.05) in RSH only and this was accompanied by larger absolute Δ total hemoglobin (+82.5 and +137%, both P < 0.001). HRV did not change either supine or standing positions.ConclusionFive repeated sprint training sessions in hypoxia using tennis specific shuttle runs improve physiological and technical responses to TEST, RSA, and accompanying muscle perfusion responses in well-trained tennis players.

Purpose: To examine physiological and technical responses to repeated-sprint training in normobaric hypoxia at ∼3,000 m (RSH, n = 11) or in normoxia (RSN, n = 11) compared to a control group (CON, n = 8) in well-trained tennis players. Participants were 28.8 ± 5.9 years old without any previous experience of training in hypoxia. Methods: In addition to maintaining their usual training (CON), both RSH and RSN groups completed five tennis specific repeated-shuttle sprint sessions (4 × 5 × ∼8 s maximal sprints with ∼22 s passive recovery and ∼5 min rest between sets) over 12 days. Before (Pre), the week after (Post-1) and 3 weeks after Post-1 (Post-2), physical/technical performance during Test to Exhaustion Specific to Tennis (TEST), repeated-sprint ability (RSA) (8 × ∼20 m shuttle runs—departing every 20 s) and heart rate variability (HRV) were assessed. Results: From Pre to Post-1 and Post-2, RSH improved TEST time to exhaustion (+18.2 and +17.3%; both P < 0.001), while the "onset of blood lactate accumulation" at 4 mmol L–1 occurred at later stages (+24.4 and +19.8%, both P < 0.01). At the same time points, ball accuracy at 100% V̇O2max increased in RSH only (+38.2%, P = 0.003 and +40.9%, P = 0.007). Markers of TEST performance did not change for both RSN and CON. Compared to Pre, RSA total time increased significantly at Post-1 and Post-2 (−1.9 and −2.5%, P < 0.05) in RSH only and this was accompanied by larger absolute Δ total hemoglobin (+82.5 and +137%, both P < 0.001). HRV did not change either supine or standing positions. Conclusion: Five repeated sprint training sessions in hypoxia using tennis specific shuttle runs improve physiological and technical responses to TEST, RSA, and accompanying muscle perfusion responses in well-trained tennis players. [ABSTRACT FROM AUTHOR]

Purpose: We determined whether running mechanics and leg muscle activity patterns for pre-activation (50 ms prior to foot contact) and loading (first half, second half and entire stance) phases vary between early, late and entire acceleration phases during repeated treadmill sprints. Methods: Ten male athletes performed three sets of five 5-s sprint accelerations (25-s and 3-min recovery between sprints and sets, respectively) on an instrumented treadmill. Ground reaction forces and surface EMG data (root mean square values of vastus lateralis, rectus femoris, biceps femoris, gastrocnemius medialis, gastrocnemius lateralis and tibialis anterior muscles of the right leg) corresponding to early, late and entire acceleration (steps 2, 4 and 6; steps 8, 10 and 12; and all steps, respectively) have been compared. Results: Independently of fatigue, vertical and horizontal forces, contact time, step length, and step frequency differed as running velocity increased over different sprint acceleration sections (all P < 0.05). For pre-activation, first half, second half and entire stance phases taken separately, each of the six studied muscles displayed specific main sprint number and analysis section effects (all P < 0.05). However, there was in general no significant interaction between sprint number and analysis section (all P > 0.27). Conclusion: During repeated treadmill sprints, ground reaction force variables and leg muscle activity patterns can vary between early, late and entire acceleration phases. Identification of neuro-mechanical adjustments across the gait cycle with fatigue, however, did not differ when considering all steps or only a few steps during the early or late acceleration phases. [ABSTRACT FROM AUTHOR]

El objetivo de este trabajo era aplicar dos baterías de evaluación de la condición física en árbitros de fútbol no profesionales, en un intento de determinar cuál puede ser más específica para este colectivo. Los árbitros (n=10) fueron evaluados en tres momentos de la temporada (T1, T2, T3), realizando la batería actualmente utilizada por la Federación de Fútbol de la Comunidad Valenciana (FFCV) (RSA: 6x40m/90”; Resistencia: carrera de 2000m) y otra de nueva propuesta (RSA: 7x30m/25”; Resistencia: Test Interválico para la Valoración de la Resistencia Específica en Fútbol, TIVRE-F). La Velocidad Aeróbica Máxima (VAM) de los árbitros aumentó significativamente en el TIVRE-F entre T1 y T3. El test 7x30/25” registró mayores índices de fatiga que 6x40/90” en T2 y T3. Con este trabajo se han obtenido nuevos datos sobre las pruebas que la FFCV utiliza en sus árbitros, concluyendo que la propuesta podría ajustarse en mayor medida a las necesidades de evaluación.

Football players need to be able to perform high-intensity efforts of short duration with brief recovery periods. The aim of this study was to analyze the influence of the pitch dimension on high-intensity actions and the effect of a repeated sprint ability (RSA) test on the physical performance in different 4-against-4 (4v4) small-sided games (SSG) dimensions. Sixteen U-18 elite football players performed an RSA test between two 4v4 SSGs (pre and post) to induce fatigue and compare physical data. Speed, sprint number, accelerations, sprint distance, total distance covered, and total distance covered of the players at different intensities were evaluated in 3 different SSGs (125, 150, 250, and 300 m2). Results revealed a significant detriment of physical performance in the 125-m² SSG after RSA, mostly in number of sprints (-6.56; confidence interval [CI] 95%: -10.13 to -3.00; effect size [ES]: 1.13 p, 0.001), accelerations (-2.69; CI 95%: 25.13 to -0.24; ES: 0.68; p = 0.032), and sprint distance (-65.44 m; CI 95%: -103.73 to -27.16; ES: 1.20; p = 0.001). In bigger SSGs (-50 and 300 m²), higher distance at high intensity was covered and Vmax, Vmean, and sprint distance were greater. In summary, accelerations, sprint number, and fatigue were higher in smaller pitches, and higher velocities were reached in bigger SSGs. Football players should be aware that changes in pitch size can modify the physical performance on highintensity actions in SSGs. [ABSTRACT FROM AUTHOR]

The physical match demands of female field hockey are intense and may differ according to playing positions. In addition, conducting sports-specific field tests can assist coaches in determining their players' preparedness for competition. There is limited research regarding the match demands and relevance of field testing at premier league levels. Therefore, the aims were to describe the physical match demands of female premier league (amateur) field hockey, and to determine the relationships between match activity patterns and physical performance tests. Match activity and heart rate data were collected from 32 female participants using the Zephyr BioHarness 3 system. Participants also performed the Yo-Yo intermittent recovery (level 1) (n = 22), repeated sprint ability (n = 21), and the heart rate recovery (n = 16) tests. Moderate to large effect sizes were observed when defenders were compared with midfielders and forwards for time spent (%) in standing/walking and jogging (d = 0.64-1.30) in addition to the playing time (%) spent in the low-to-moderate and very high heart rate zones (d = 0.69-0.85). Heart rate recovery (10 s) correlated with the playing time (%) spent in sprinting (r = 0.73, p = 0.002). Heart rate recovery (60 s) and the Yo-Yo intermittent recovery test both correlated with the playing time (%) spent in running (r = 0.77, p = 0.0006 and r = 0.54, p = 0.01). The differences in physical match demands between positions emphasize the importance of training specificity at premier league levels. The heart rate recovery test can be used to assess a female field hockey player's capability to perform high-intensity match activity. [ABSTRACT FROM AUTHOR]

The purpose of the study was to describe the training load distribution of a young female water polo team in different cycles of the season and verify its subsequent effects on specific fitness measured by the repeated sprints ability (RSA) test, aerobic endurance measured by the lactate minimum test, incidence and severity of upper respiratory tract infection (URTI) symptoms, and muscle damage markers. The training load (i.e., rating of perceived exertion × session duration) of 20 young female water polo players (mean ± SD: age = 15.65± 1.× years; body mass=60.9×611.0 kg; height=1.62±0.1 m) was monitored, and the incidence and severity of URTI was assessed during part of the season. In addition, we assessed the lactate minimum speed (LMS), RSA, creatine kinase (CK), and lactate dehydrogenase (LDH) blood concentration during the season. The level of significance set was p < 0.05. The training loads were higher in the specific period (p<0.01), whereas a high incidence of URTI was observed in the general cycle. The LMS was greater in the general cycle (p < 0.05), whereas total time and best time in the RSA test were greater in the competitive cycle (p < 0.05). The CK and LDH concentrations were significantly lower during the competitive cycle (p < 0.01). The general cycle of a female water polo team is critical regarding URTI and muscle damage, even with smaller training loads than the specific period. [ABSTRACT FROM AUTHOR]

Copyright of SPORMETRE: The Journal of Physical Education & Sport Sciences / Beden Eğitimi ve Spor Bilimleri Dergisi is the property of SPORMETRE: The Journal of Physical Education & Sport Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Andaluza de Medicina del Deporte is the property of Centro Andaluza de Medicina del Deporte and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

مقدمه: با توجه به انجام انواع فعالیت‌های ورزشی طی مسابقات ورزشی، میزان خستگی و چگونگی کاهش آن متفاوت است. بر همین اساس، هدف از انجام مطالعه حاضر، بررسی میزان تغییرات مجذور میانگین ریشه (Root mean square یا RMS) و فرکانس متوسط (Median frequency یا MDF) عضلات چهارسر رانی و همسترینگ، به عنوان عوامل خستگی عصبی- عضلانی پس از غوطه‌وری در آب سرد به دنبال Repeated-sprint ability (RSA) بود. مواد و روش‌ها: به این منظور، 20 ورزشکار تمرین کرده، برای شرکت در این پژوهش انتخاب شدند. پس از انجام فعالیت سرعتی تکراری، 10 نفر از آزمودنی‌ها داخل آب سرد با دمای 14 درجه‌ سانتی‌گراد و 10 نفر دیگر در دمای اتاق به شکل غیر فعال قرار گرفتند. اندازه‌گیری الکترومایوگرافی (Electromyography یا EMG) حین حداکثر انقباض ارادی قبل و پس از انجام هر ست RSA و همچنین، پس از Cold water immersion (CWI) یا استراحت غیر فعال و پس از 24 ساعت انجام شد. یافته‌ها: پس از RSA در روز اول، کاهش معنی‌داری در RMS عضلات پهن جانبی [037/0 = PCWI، 010/0 = PCON (PControl)] و راست رانی (001/0 = PCON, CWI) رخ داد و همچنین، MDF عضله پهن جانبی تغییرات معنی‌داری (100/0 = PCWI و 850/0 = PCON) طی فعالیت سرعتی تکراری نداشت، در حالی که مقادیر MDF عضله راست رانی، به طور مستقیم پس از آب سرد (001/0 > P) و در آخرین ست روز دوم (030/0 = P) کاهش معنی‌داری را نشان داد. نتیجه‎گیری: این پژوهش نشان داد که غوطه‌وری در آب سرد، در مقایسه با ریکاوری غیر فعال، تأثیر معنی‌داری بر عملکرد عصبی- عضلانی ندارد.

Study aim: The purpose of this study was to examine the effects of a repeated sprint training program in addition to volleyball training on the aerobic capacity of college volleyball players.

Objective: This study examined the effects of oral and topical (PR Lotion; Momentous) sodium bicarbonate (NaHCO 3 ) during a battery of team sport-specific exercise tests., Method: In a block randomized, crossover, double-blind, placebo-controlled design, 14 recreationally trained male team sport athletes performed a familiarization visit and three experimental trials receiving: (i) 0.3 g·kg -1 body mass (BM) NaHCO 3 in capsules + placebo lotion (SB-ORAL), (ii) placebo capsules +0.9036 g·kg -1 BM PR Lotion (SB-LOTION), or (iii) placebo capsules + placebo lotion (PLA). Supplements were given ~120 min prior to the team sport-specific exercise tests: countermovement jumps (CMJ), 8 × 25 m repeated sprints and Yo-Yo Intermittent Recovery Level 2 (Yo-Yo IR2). Blood acid-base balance (pH, bicarbonate) and electrolytes (sodium, potassium) were measured throughout. Rating of perceived exertion (RPE) was recorded after each sprint and post-Yo-Yo IR2., Results: Distance covered during the Yo-Yo IR2 was 21% greater for SB-ORAL compared with PLA (+94 m; p  = 0.009, d  = 0.64) whereas performance was only 7% greater for SB-LOTION compared with PLA (480 ± 122 vs. 449 ± 110 m; p  = 0.084). Total completion time for the 8 × 25 m repeated sprint test was 1.9% faster for SB-ORAL compared with PLA (-0.61 s; p  = 0.020, d  = 0.38) and 2.0% faster for SB-LOTION compared with PLA (-0.64 s; p  = 0.036, d  = 0.34). CMJ performance was similar between treatments ( p  > 0.05). Blood acid-base balance and electrolytes were significantly improved for SB-ORAL compared with PLA, but no differences were observed for SB-LOTION. Compared to PLA, RPE was lower for SB-LOTION after the fifth ( p  = 0.036), sixth ( p  = 0.012), and eighth ( p  = 0.040) sprints and for SB-ORAL after the sixth ( p  = 0.039) sprint., Conclusions: Oral NaHCO 3 improved 8 × 25 m repeated sprint (~2%) and Yo-Yo IR2 performance (21%). Similar improvements in repeated sprint times were observed for topical NaHCO 3 (~2%), but no significant benefits were reported for Yo-Yo IR2 distance or blood acid-base balance compared to PLA. These findings suggest that PR Lotion might not be an effective delivery system for transporting NaHCO 3 molecules across the skin and into systematic circulation, therefore further research is needed to elucidate the physiological mechanisms responsible for the ergogenic effects of PR Lotion.

The aim of this investigation was to determine age-related trends for anthropometric and physical variables in elite young soccer players. For this purpose, a total of 114 young male soccer players from a high-performance soccer academy participated in this investigation. Anthropometric and physical variables (countermovement jump, 6×40 m shuttle run test, 2×11 m slalom test with the ball) were determined. Results. Body height (U15U20; p<0.01). However, the relationships of these variables with age were explained by curvilinear polynomial equations with a tendency for plateauing at ~17 years of age. There were also age-based differences in maximal running velocity (U15

This study analyzed the effects of a resistance-type circuit training (RCT) program (30-35 minutes, performed twice a week for 10 weeks) on male handball players. Twenty-two male players were divided into experimental (E; age 20.3 ± 0.5 years) and control groups (C; age 20.1 ± 0.5 years). Measures before and after RCT included squat jump (SJ), countermovement jump (CMJ), 1 repetition maximum (1RM) of bench press, pull-over and back half-squats, throwing velocity (a 3-step running throw [RT], and a jump throw [JT]), repeated-sprint ability (six 2 x 15-m shuttle sprints with recording of best time for a single trial), anthropometric estimates of leg- and thigh-muscle volumes and mean thigh cross-sectional area (CSA), and a test of agility. The agility T-half test showed a significant interaction effect (p = 0.001; η² = 0.422), with an intergroup difference in effect size (d) of 1.27 (dTG = 1.24 vs. dCG = -0.03). The SJ displayed no interaction effect. The interaction effects for half back squat (d = 2.73, η² = 0.740) and CMJ (d = 3.76, η² = 0.700) were large, but that for RT was smaller (η² = 0.460) than that for JT (η² = 0.745). The throwing velocity of C decreased for both measures, with negative effect sizes (d = -0.18 and d = -0.93, respectively). Upper-body, leg, and thigh-muscle volumes and thigh CSA increased significantly after resistance training. However, repeated-sprint parameters showed no significant changes. During the competitive season, 10 weeks of RCT with only 2 training sessions per week improved numerous measures of athletic performance in handball players, and such conditioning can be highly recommended as part of the annual training program for elite handball players. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the effects of 6 successive days of repeated sprint (RS) training in moderate hypoxia on anaerobic capacity in 100-200-m sprint runners. Eighteen male sprint runners (age, 20.0 ± 0.3 years; height, 175.9 ± 1.1 cm; and body mass, 65.0 ± 1.2 kg) performed repeated cycling sprints for 6 consecutive days in either normoxic (NOR; fraction of inspired oxygen [FiO2], 20.9%; n = 9) or hypoxic conditions (HYPO; FiO2, 14.5%; n = 9). The RS ability (10 x 6-second sprints), 30-second maximal sprint ability, maximal oxygen uptake (...O2max), and 60-m running time on the track were measured before and after the training period. Intramuscular phosphocreatine (PCr) content (quadriceps femoris muscle) was measured by 31P-magnetic resonance spectroscopy (31P-MRS) before and after the training period. Both groups showed similar improvements in RS ability after the training period (p < 0.05). Power output during the 30-second maximal sprint test and ...O2max did not change significantly after the training period in either group. Running time for 0-10 m improved significantly after the training period in the HYPO only (before, 1.39 ± 0.01 seconds; after, 1.34 ± 0.02 seconds, p < 0.05). The HYPO also showed a significant increase in intramuscular PCr content after the training period (before, 31.5 ± 1.3 mM; after, 38.2 ± 2.8 mM, p < 0.05). These results suggest that sprint training for 6 consecutive days in hypoxia or normoxia improved RS ability in competitive sprint runners. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the effect of core strength training performed on a stable surface (CTS) compared with core strength training performed on an unstable surface (CTU) on physical fitness (jump performance, sprint, and repeated sprint ability (RSA)) and quality of movement (Fundamental Movement Screen) in professional female futsal players. Fourteen professional female futsal players (mean age: 23.7 ± 5.1 years, age range: 18-28 years) were randomly assigned to a CTS (n = 7) or a CTU (n = 7) group. The intervention program was carried out 3 times a week over 6 weeks. Players of both groups performed the same four core-strengthening exercises. The only difference between the two interventions was that the CTU group performed all exercises (i.e., shoulder bridge, side bridge, prone plank, and crunch) on an unstable surface (Togu® Dyn-Air). Within-group analysis showed significant improvements (p < 0.001) in 10 m sprint performance from the pre- to post-test in the CTS (+4.37%) and CTU (+5.00%) groups. Players in both the CTS (+10.39%) and CTU (+11.10%) group also showed significant enhancement in the Functional Movement Screen total score, from the pre-test to post-test. In addition, a significant time effect was also observed for the CTU group in the relative score of the RSA test decreasing from the pre- to post-test (-30.85%). In the between-groups analysis, there were no significant differences between the core strength training groups (CTS vs CTU) in any variable. To conclude, sprint and Functional Movement Screen performance improved following CTS and CTU when conducted in combination with regular futsal training. In addition, CTU had limited benefit in RSA compared to CTS. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the association between the MCT1 (monocarboxylate transporter 1) A1470T polymorphism and positional roles in a large cohort of professional football players from five different countries. We compared genotype distributions of the MCT1 A1470T polymorphism between football players (n = 694) and non-athlete controls (n = 781) from Italy, Poland, Lithuania, Ukraine and Malta, and we analyzed the MCT1 genotype distributions with respect to the players' positions in the field (e. g. forwards, midfielders, defenders and goalkeepers). Genomic DNA was extracted from either buccal epithelium or peripheral blood using a standard protocol. In the pooled cohort of Italian, Polish, Lithuanian and Ukrainian football players, forwards (n = 148) were more likely than controls (n = 781) to possess the A allele ( χ² = 7.067, p = 0.029, FDR q value 0.116), with a greater likelihood of having the AA genotype compared with the TT genotype (OR = 1.97; C.I. = 1.07-3.64; p = 0.021, FDR q value 0.086). The MCT1 AA genotype was significantly more frequent in forwards then in controls. Further studies are needed to confirm these findings in other professional football player cohorts. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the parameters distinguishing top female futsal players from lower level players. Twenty-seven female futsal players participated in the study, composed of professional first division (elite; n=15) players and semi-professional second division players (sub-elite; n=14). Active and passive straight leg raise tests, isokinetic strength of the knee extensor and flexor muscles at 60º • s-1 angular velocity, squat and counter movement jumps, 30 m sprint, 30 m agility, repeated sprint ability test and maximum ball speed during shooting were measured. The elite players were more agile and kicked harder than sub-elite players in maximum ball speed during the shooting test (P≤0.05). However, no significant differences between teams were observed in active and passive hamstring flexibility, jumping ability, repeated sprint ability test, 30 m sprint time, H/Q ratio and absolute and relative torque from 60° • s-1 angular velocity. Based on these findings we conclude that agility and maximum ball speed during shooting may be important determinant factors of Spanish female futsal actions and could distinguish ability at high-level games.

The purpose of this study was to compare anthropometric and functional profiles of 13-to-17-year-old soccer players according to their competitive level. Height, body mass, percentage of body fat, countermovement jump height, change of direction ability, 5- and 15-m sprint times, repeated sprint ability (RSA), intermittent recovery performance, and dribbling skills were collected in 115 young Italian soccer players. Players were divided into selected (i.e., competing at national level, n = 17 U15 and 47 U17) and non-selected (i.e., competing at regional level, n = 43 U15 and 8 U17) groups. U17 selected players were taller, quicker over 5 and 15 m, more agile, and had better RSA, prolonged intermittent recovery ability, and dribbling skills than their non-selected counterparts (d = 0.28–0.55, p < 0.05). In particular, selected players showed lower times on the first three and the last shuttle of the RSA test (d = 0.28–0.34, p < 0.05). No significant differences were observed in U15 players (p > 0.05). Discriminant analysis revealed that dribbling skills, 15-m sprint time, and height best discriminate U17 players by competitive level (p < 0.001). Anthropometric characteristics and functional abilities can discriminate across competitive standards between male U17 but not U15 soccer players. In particular, these findings suggest the importance of dribbling skills, 15-m sprint, and height in U17 players.

The purpose of study was to resolve the effect of plyometric training and repeated sprint training on physical performance. The study was conducted on 41 subjects in two experimental groups (plyometric/repeated sprints training). Before and after the training program, subjects were subjected to diagnostic procedures that included standard test protocols. Results proved a statistically significant difference only after the plyometric training program compared to the repeated sprint group in countermovement jump (8.65% vs. 2.21%). In variable repeated jumps, an increased value was recorded (2.9% vs. 4.29%), like in sprint variables after the training program where certain trends of progress happened after the repeated sprint ability training and the specificity of the program (5 m = 0.89%, 10 m = 1.07% and 25 m = 1.35%), while plyometric training recorded unchanged values at 5 and 10 m, and a 0.27% improvement at 25 m. Stagnation of the 20-yard test was recorded in both groups. There was no difference between training programs in any variables of functional capacities, with similar measures recorded in repeated sprint ability. After six weeks of both training types, positive changes can be expected in explosive strength of lower extremities, increases in acceleration area, and maximum speed.

Introduction: Ice hockey is a complex sport requiring multiple athletic and technical attributes. Considering the variety of tests developed, on-ice testing protocols have been created to measure the physiological and mechanical attributes associated with performance. To our knowledge, a lack of technical resources exists to help stakeholders opt for on-ice protocols from among those developed. It becomes crucial for researchers and practitioners to select relevant and context-specific procedures. This systematic review of the literature outlines an inventory of the on-ice tests that have been used in the domain of ice hockey research over the last twenty years, and summarize protocols mostly used in major athletic components., Methods: A search was performed on three databases (PubMed, SPORTDiscus and Scopus) by following the PRISMA guidelines. Specific keywords were selected to find publications using on-ice testing protocols in the methodology. Four aspects of athletic attributes were used to categorize the protocols: aerobic capacity, acceleration-speed, agility-change of direction and ability to repeat skating sprints. Analyses were conducted regarding four categories of observations: population under study, on-ice reported test(s), outcomes measures and main findings., Results: A total of 107 articles were included, resulting in 55 on-ice tests related to the on-ice assessments of four major athletic components: aerobic capacity ( n  = 7), acceleration-speed ( n  = 6), agility and change of direction ( n  = 23) and repeated skating sprint ability ( n  = 19). Testing in male and older cohorts (≥16 years old) predominates, with a primary focus on the competitive amateur level. The selected tests were mainly designed for assessing on-ice physiological responses and fitness ( n  = 38), talent identification-team selection ( n  = 19), efficiency of interventions ( n  = 17) and validation purposes ( n  = 16)., Conclusion: A prevalence of on-ice skating tests to assess the ability to repeat intense efforts, agility, acceleration and speed components exists, which are relevant and linked to match requirement. The wealth of on-ice tests used in the literature reflects the need to adapt the on-ice evaluation process to the population, constraints, and goals. This review is a valid toolbox and can benefit for researchers and practitioners interested in testing hockey players from different levels, with a variety of aims and needs, by helping them to select the relevant procedures to their environment and practice context., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Bournival, Martini, Trudeau and Lemoyne.)

The aim of this study was to compare the effects of plyometric and jump training on physical performance in young male handball players. Twenty-six young male handball players were divided into two sub-groups to perform a five-week pre-season training programme supplemented with two ground-reactive protocols with an equal number of jumping exercises referred as to ground contacts: plyometric training (PLY; n = 14) and standard jump training (CON; n = 12). Before and after training, repeated sprint ability (RSA), jumping ability (JA), maximal oxygen uptake (VO2max) and aerobic power at the anaerobic threshold (PAT) were measured. A two-factor analysis revealed significant time effects with improvements in fat mass (p = 0.012), maximal power during the incremental cycling test (p = 0.001) and PAT (p < 0.001), power decline (PDEC) and maximal power (Pmax) in the 5th repetition (p < 0.05 and p < 0.01, respectively). The training-induced changes in absolute and relative peak power in the RSA test and absolute VO2max approached significance (p = 0.06, p = 0.053 and p = 0.06). No intervention time x exercise protocol effects were observed for any indices of JA, RSA and aerobic capacity. A five-week pre-season conditioning programme supplemented with only 15 sessions of plyometric exercise did not induce any additional benefits, compared to a matched format of standard jump training, in terms of improving jumping performance and maximal power in the RSA test. Aerobic capacity and the fatigue index in RSA were maintained under these two training conditions. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the importance of skating economy to fatigue during repeated high-intensity efforts of a simulated ice hockey shift. Forty-five collegiate and Junior A male ice hockey players (aged 18-24 years) performed a continuous graded exercise test using a skate treadmill. Breath-by-breath data for oxygen consumption (...O2) and respiratory exchange ratio were collected and used to derive energy expenditure (EE) averaged over the final 10 seconds of each stage. Economy was determined as the slope of the regression line relating V...O2 and EE against skating speed separately. Participants also completed 8 bouts of maximal ice skating through a course designed to simulate typical shift, with timing gates determining first half, second half, and total fatigue decrement, calculated by a percent decrement score. Partial correlation was used to determine the association between economy measures and decrement during the repeated-shift test. Twenty-six participants met inclusion criteria and were included in data analysis. Skating economy measures (both relative ...O2 and EE) were very likely moderate positive correlates of total fatigue decrement (r [95% confidence interval]: ...O2, 0.46 [0.09, 0.72] and EE, 0.44, [0.06, 0.71]) but not with first or second gate decrement. Our results indicate that skating economy plays an important role in fatigue resistance over repeated on-ice sprints designed to simulate a typical shift. This supports the use of technical skating coaching and training techniques to enhance skating economy as a means of improving ice hockey performance. [ABSTRACT FROM AUTHOR]

Physical performance is a key factor in most of the actions that determine success in soccer competitions. The present meta-analysis aimed to determine whether, and to what extent different conditioning programmes implemented in addition to regular soccer training are able to enhance the performance of high-velocity soccer-related tasks. Study groups were categorised according to type of performance measurement: (A) vertical jump ability, (B) linear sprint performance, (C), change of direction with ball, (D) change of direction without ball, (E) repeated sprint ability, and (F) kicking performance. Subgroup analyses were done with reference to the type of conditioning programme applied: (A) resistance training, (B) plyometric, (C) sprint and/or change of direction, and (D) combined methods. The standardised mean differences (SMD) along with 95% confidence intervals (95% CI) were calculated using the Review Manager 5.3 software. The application of a conditioning programme was associated with a significant improvement in vertical jump ability (SMD = 0.64 [95% CI: 0.50–0.77]), linear sprint (SMD = −0.79 [95% CI: −0.61 to −0.96]), change of direction with ball (SMD = −0.78 [95% CI: −0.42 to −1.15]), change of direction without ball (SMD = −0.83 [95% CI: −0.61 to −1.05]), repeated sprint ability (SMD = −0.51 [95% CI: −0.19 to −0.84]), and kicking performance (SMD = 0.78 [95% CI: 0.34–1.22]). No clear differences among the different conditioning programmes were observed. The implementation of a conditioning programme in addition to regular soccer training enhances the performance of high-velocity soccer-related tasks. [ABSTRACT FROM AUTHOR]

During supramaximal exercise, exacerbated at exhaustion and in hypoxia, the circulatory system is challenged to facilitate oxygen delivery to working tissues through cerebral autoregulation which influences fatigue development and muscle performance. The aim of the study was to evaluate the effects of different levels of normobaric hypoxia on the changes in peripheral and cerebral oxygenation and performance during repeated sprints to exhaustion. Eleven recreationally active participants (six men and five women; 26.7 ± 4.2 years, 68.0 ± 14.0 kg, 172 ± 12 cm, 14.1 ± 4.7% body fat) completed three randomized testing visits in conditions of simulated altitude near sea-level (~380 m, FIO2 20.9%), ~2000 m (FIO2 16.5 ± 0.4%), and ~3800 m (FIO2 13.3 ± 0.4%). Each session began with a 12-min warm-up followed by two 10-s sprints and the repeated cycling sprint (10-s sprint: 20-s recovery) test to exhaustion. Measurements included power output, vastus lateralis, and prefrontal deoxygenation [near-infrared spectroscopy, delta (Δ) corresponds to the difference between maximal and minimal values], oxygen uptake, femoral artery blood flow (Doppler ultrasound), hemodynamic variables (transthoracic impedance), blood lactate concentration, and rating of perceived exertion. Performance (total work, kJ; −27.1 ± 25.8% at 2000 m, p < 0.01 and −49.4 ± 19.3% at 3800 m, p < 0.001) and pulse oxygen saturation (−7.5 ± 6.0%, p < 0.05 and −18.4 ± 5.3%, p < 0.001, respectively) decreased with hypoxia, when compared to 400 m. Muscle Δ hemoglobin difference ([Hbdiff]) and Δ tissue saturation index (TSI) were lower (p < 0.01) at 3800 m than at 2000 and 400 m, and lower Δ deoxyhemoglobin resulted at 3800 m compared with 2000 m. There were reduced changes in peripheral [Δ[Hbdiff], ΔTSI, Δ total hemoglobin ([tHb])] and greater changes in cerebral (Δ[Hbdiff], Δ[tHb]) oxygenation throughout the test to exhaustion (p < 0.05). Changes in cerebral deoxygenation were greater at 3800 m than at 2000 and 400 m (p < 0.01). This study confirms that performance in hypoxia is limited by continually decreasing oxygen saturation, even though exercise can be sustained despite maximal peripheral deoxygenation. There may be a cerebral autoregulation of increased perfusion accounting for the decreased arterial oxygen content and allowing for task continuation, as shown by the continued cerebral deoxygenation.