Repeated Sprint Test Research Articles

Crocus Sativus Linnaeus (Saffron) intake does not affect physiological and perceptual responses during a repeated sprint test in healthy active young males

The study aimed to investigate the effects of acute ingestion of saffron (SAF) on physiological (i.e., heart rate and blood lactate) and perceptual (i.e., ratings of perceived exertion [RPE] and feeling scale) measures in response to a repeated-sprint ability test (RSS) in healthy young males (N = 22; mean ± SD: age, 21.7 ± 1.24 yrs.). All participants completed two experimental trials with a one-week washout period using a double-blind, placebo-controlled, crossover design. In each session, the participants were randomly chosen to receive either a capsule of saffron (300 mg) (SAF session) or a capsule of lactose (PLB session) two hours before performing the RSS.No significant differences (p > 0.05) were found for heart rate, RPE, and feeling scale between the SAF or PLB sessions at pre- and post-RSS. There were no significant changes (p > 0.05) in peak time, total time, fatigue index, and blood lactate in either the SAF or PLB sessions. Acute SAF ingestion did not significantly improve RSS performance nor physiological and perceptual measures in active young males. Future trials should address the topic by using shortened/prolonged higher doses of SAF on biological, physical, physiological, and perceptual responses to acute and chronic exercise.

Effects of Carbohydrate and Caffeine Mouth Rinsing Methods on Repetitive Kick Force and Duration, and Hand Reaction Time in Karate Athletes

The effect of carbohydrate (CHO) and caffeine (CAF) solutions rinsing in the mouth in combat sports where high-intensity movements are performed intermittently despite fatigue is unknown. This research was carried out to investigate the effects of rinsing CHO and CAF solutions in the mouth on kick force, duration, and hand reaction time in karate athletes. 16 male trained karate players (average age 21.6 years, weekly training time 8.4 hours, training experience 7.8 years) voluntarily participated in the study. In a replicated, double-blind, placebo-controlled, and crossover design study, after the 10 seconds mouth rinsing of CHO (6.4% maltodextrin), CAF (1.2%), and placebo (water) solutions in sessions, repeated sprint test (6sec sprint ×10 repetitions, with 30sec rest) on a bicycle ergometer, after light stimuli kick test (consecutive 5 times), hand reaction time test (consecutive 5 times), kick test (consecutive 5 times), hand reaction time test (consecutive 5 times) were performed respectively. The results obtained from the tests in the constructed protocol by causing fatigue (peak power, average power, minimum power, power drop; kicking reaction time, strength, power, and time; hand reaction time) were compared between sessions. The highest peak power and average power outputs (W/kg) obtained from the repeated sprint test were obtained in the CAF session, and the best kick and hand reaction times (ms) were obtained in the CAF session in the 2nd set of tests. The results obtained from this study suggest that the CAF mouth rinsing method can improve kick and hand reaction time despite fatigue in karate competitions.

Low and High Doses of Espresso Coffee Improve Repeated Sprint Performance and Eye–Hand Coordination Following Fatigue Status in Male Basketball Players

BackgroundAlthough several studies have evaluated the effect of coffee on sports performance, the effect of caffeine on sports performance during fatigue status remains unclear. ObjectivesThis study aimed to determine the effect of high and low doses of coffee on the repeated sprint test (RST), perceived fatigue (PF), and eye–hand coordination following physical fatigue status in male basketball players. MethodsTwenty-four male basketball players were randomly placed in 4 conditions including 1) low-dose espresso coffee (LDEC); 2) high-dose espresso coffee (HDEC); 3) decaffeinated espresso coffee (PLA); and 4) no drinking (CON). PF and eye–hand coordination were measured using the soda pop test (SPT) at baseline, immediately after the RST, and 5 min after the 10 all-out sprints with a 30-s interval of RST. ResultsThe time of the first to tenth sprints (RST1 to RST10), total time (RST-TT), mean time (RST-MT), best time (RST-BT), and percentage of performance decrement (PD) were recorded. Coffee dose-dependently significantly improved RST-TT, RST-MT, and RST-BT compared with PLA and CON. PF increased significantly in all conditions immediately after RST compared with baseline. Five minutes after RST, PF was reduced compared to immediately after RST. Immediately after RST, coffee reduced PF dose-dependently compared with PLA and CON. SPT decreased immediately after RST in PLA and CON compared with baseline, whereas no significant change was observed for LDEC and HDEC. At baseline and immediately after RST, coffee and placebo consumption increased SPT performance compared with CON. Immediately and 5 min after RST, coffee increased SPT performance compared to PLA dose-dependently. ConclusionsHDEC and LDEC improved RST performance and eye–hand coordination in male basketball players. However, HDEC showed a more profound effect compared with LDEC.

Investigation of Some Biomotoric Characteristics of Young German and Turkish Football Players

This research aimed to examine the biomotoric characteristics of Turkish and German young football players living in Germany. 32 football players participated in the research. Repetitive sprint test, agility test, vertical jump test and Sanding long jump test were applied to the football players. The physical and performance characteristics of the research group were analyzed using descriptive statistics and Mann Whitney U test. The results showed that there was a significant difference between the total times of the repeated sprint test and the total times of the repeated sprint test. There was no significant difference between the biomotoric characteristics between the groups, except for repeated 3-4-5 sprints and total times. Turkish football players completed the repetitive sprint test in a shorter time than German football players, but there was no difference in their fatigue index. This result seems meaningful considering that Turkish football players live in Germany, grow up in Germany, have similar environmental conditions, train similarly and play in the same league.

Energy System Contributions in Repeated Sprint Tests: Protocol and Sex Comparison.

The aim of this study was to investigate the energy system contributions to different repeated sprint protocols and also to determine sex-related differences in these contributions. Sixteen men and fourteen women team sport athletes randomly performed two cycling repeated sprint protocols with the same total duration (10 x 6 s and 6 x 10 s). Relative peak power (RPP), relative mean power (RMP), performance decrement (PD), oxygen uptake (VO2), blood lactate (LA), heart rate (HR) and ratings of perceived exertion (RPEs) were measured. The contributions of energy systems were calculated from oxygen consumption and lactate values during rest, exercise and recovery phases based on mathematical methods. Findings indicate that men had higher RPP and RMP. RPP did not differ according to protocols, while RMP was higher in the 10 x 6 s protocol. The sex effect in PD was similar; however, it was higher in the 6 x 10 s protocol. The effects of protocols on the maximum HR and LA were similar; however, the 6 x 10 s protocol resulted in higher RPEs. In both protocols women had higher ATP-PCr and men had higher glycolytic system contribution with similar oxidative system contribution. In addition, the 10 x 6 s protocol had higher ATP-PCr system contribution and the 6 x 10 s protocol had higher glycolytic system and oxidative system contributions. In conclusion, the contribution of energy systems, physiological and performance variables showed variations according to sex and different protocols.

Does "Live High-Train Low and High" Hypoxic Training Alter Stride Mechanical Pattern During Repeated Sprints in Elite Team-Sport Players?

We examined changes in stride temporal parameters and spring-mass model characteristics during repeated sprints following a 3-week period of "live high-train low and high" (LHTLH)altitude training in team-sport players. While residing under normobaric hypoxia (≥14h/d; inspired oxygen fraction [FiO2] 14.5%-14.2%) for 14days, elite field hockey players performed, in addition to their regular field hockey practice in normoxia, 6 sessions (4 × 5 × 5-s maximal sprints; 25-s passive recovery; 5-min rest) under either normobaric hypoxia (LHTLH; FiO2 ∼14.5%, n = 11) or normoxia (live high-train low; FiO2 20.9%, n = 12). A control group (live low-train low; FiO2 ∼20.9%, n = 9) residing in normoxia without additional repeated-sprint training was included. Before (Pre)and a few days (Post-1) and 3weeks (Post-2) after the intervention, stride mechanics were assessed during an overground repeated-sprint test (8 × 20m, 20-s recovery). Two-way repeated-measures analysis of variance (time [Pre, Post-1, and Post-2] × condition [LHTLH, live high-train low, and live low-train low]) were conducted. Peak sprinting speed increased in LHTLH from Pre to Post-1 (+2.2% [2.0%]; P = .002) and Post-2 (+2.0% [2.4%]; P = .025), with no significant changes in live high-train low and live low-train low. There was no main effect of time (all P ≥ .062), condition (all P ≥ .771), or a significant time × condition interaction (all P ≥ .230) for any stride temporal variable (contact time, flight time, stride frequency, and stride length) or spring-mass model characteristics (vertical and leg stiffness). Peak sprinting speed improved in elite field hockey players following LHTLH altitude training, while stride mechanical adjustments to repeated overground sprints remained unchanged for at least 3weeks postintervention.

The Relationship Between Lower-Body Force-Time Variables and Skating Performance in Female Ice Hockey Players.

Ice hockey is a team invasion sport characterized by repeated high-intensity skating efforts, technical and tactical skill, physical contact, and collisions requiring considerable levels of muscular strength. The purpose of this study was to evaluate the relationships between lower-body vertical force-time metrics and skating qualities in subelite female ice hockey players. A cross-sectional cohort design was employed utilizing 14 athletes (body mass = 66.7 [1.8]kg; height = 171.6 [6.2]cm; age = 21.1 [1.7]y). The relationships between metrics of lower-body strength collected from a drop jump, squat jump, countermovement jump, loaded countermovement jump, and an isometric squat and 4 skating qualities collected from a linear sprint, repeated sprint test, and a multistage aerobic test were evaluated. The regression models revealed a positive relationship between relative peak force in the isometric squat and skating multistage aerobic test performance (r2 = .388; P = .017) and a positive relationship between repeated-sprint ability and eccentric mean force during the loaded countermovement jump (r2 = .595; P = .001). No significant relationships were observed between strength metrics and skating acceleration or maximal velocity. These data suggest that skating ability is most affected by relative isometric strength in female ice hockey players. It is recommended that practitioners focus training on tasks that improve relative force output. It is also recommended that isometric relative peak force be used as a monitoring metric for this cohort.

Influence of Maturation and Determinants of Repeated-Sprint Ability in Youth Basketball Players.

Gonzalo-Skok, O, and Bishop, C. Influence of maturation and determinants of repeated-sprint ability in youth basketball players. J Strength Cond Res 38(2): 325-333, 2024-The main aims of the current study were (a) to determine the main predictors of general and specific repeated-sprint ability (RSA) tests, (b) to analyze the relationships between RSA tests and independent measures of physical performance, (c) to examine whether between-age differences exist, and (d) to assess whether maturation affects those mentioned above in young basketball players. Thirty-five young (U-14 to U-16), highly trained basketball players performed a linear sprint test (5, 10, and 25 m), an incremental running test, and 2 repeated-sprint tests (general [RSG]: 6 × 25 m; specific [RSS]: 6 × 5 + 5 m with a 45° change of direction and 20 seconds of passive recovery in both tests). Anthropometric variables were measured and used to calculate age at peak height velocity (APHV), which was used to determine maturation. The main determinants of RSA tests were aerobic performance and linear sprinting for RSS ( R2 = 0.84) and adding the percentage of body fat for RSG ( R2 = 0.94). Almost perfect relationships ( r = 0.93-0.99) were found between all RSA variables (i.e., the best [RSG b and RSS b ] and mean time [RSG m and RSS m ]). As age increased, performance in RSA was evident, as shown by improved best and mean scores. When APHV was controlled for, no significant differences were apparent in the comparison from U-14 and U-16 in 25 m, RSG b , and RSG m . By contrast, significant differences ( p < 0.05) were still evident with APHV controlled between U-14 and U-16 in 5 m, 10 m, RSS b , and RSS m . In conclusion, maturation positively affects linear sprinting and linear RSA performance, whereas specific (multidirectional) RSA seems to be related to other factors.

Listening to music during a repeated sprint test improves performance and psychophysiological responses in healthy and physically active male adults

BackgroundIt is well-documented that listening to music has the potential to improve physical performance during intense physical exercise. Less information is available on the timing of music application. This study aimed to investigate the effects of listening to preferred music during the warm up of a subsequent test or during the test on performance of repeated sprint sets (RSS) in adult males.MethodsIn a randomized cross-over design, 19 healthy males (age, 22.1 ± 1.2 years; body mass, 72.7 ± 9.3 kg; height, 1.79 ± 0.06 m; BMI, 22.6 ± 2.2 kg m−2) performed a test including 2 sets of 5*20-m repeated-sprints under one of three conditions: listening to preferred music during the test; listening to preferred music during the warm-up; or not listening to music. The assessed parameters comprised RSS performance indices, blood lactate, heart rate, the pacing strategy profile, rating of perceived exertion, and a feeling scale.ResultsFor performance indices during set 1 of the RSS test, we found a significant decrease in total sum sequence, fast time index and fatigue index in the listening to preferred music condition compared to the no music condition (total sum sequence: p = 0.006, d = 0.93; fast time index: p = 0.003, d = 0.67; fatigue index: p < 0.001; d = 1.30) and the listening to preferred music during the warm-up condition (fast time index: p = 0.002; d = 1.15; fatigue index: p = 0.006; d = 0.74). However, there was no significant effect of listening to preferred music on physical performance during set 2 of the RSS test. Compared to the no music condition, blood lactate concentrations were higher in the listening to preferred music during the test condition (p = 0.025; d = 0.92). In addition, listening to preferred music appears not to have an effect on heart rate, the pacing strategy profile, perceived exertion, and affective responses before, during and after the RSS test.ConclusionFindings from this study revealed that RSS performances were better (FT and FI indices) in the PMDT compared with the PMWU condition. Moreover, in set 1 of the RSS test, better RSS indices were found in the PMDT compared to NM condition.

Effects of beetroot juice intake on repeated performance of competitive swimmers.

Background: Beetroot juice is a sport supplement with a high level of evidence on the physical performance enhancement. However, in swimming, there is no clear data about the effects of beetroot juice on performance. Objective: To investigate whether an acute intake of beetroot juice (BJ) improves the performance of competitive swimmers in a repeated maximum swimming effort. Method: Thirteen national-level swimmers (six females and seven males), participated in this randomized, double-blind crossover study. In two different trials, swimmers ingested a 70-mL placebo shot (.04mmol NO3 -; PLA) or a 70-mL Beet-It shot (6.4mmol of NO3 -beet juice [BJ]) 3h before undergoing a 6 × 100-m front-crawl maximal effort test with 7min rest between each 100m. Results: Overall, 100-m times showed no difference between the BJ and PLA groups (p = .364), although a possibly shorter time was observed for BJ in the last repetition (p = .104; mean difference [MD] = -.99s, mean-based inference [MBI] = 49/51/0). Participants in the BJ condition showed a possibly lower rate of perceived exertion in the first (p = .242, MD = -.85, MBI = 70/28/2) and second repetitions (p = .165, MD = 1.15, MBI = 83/16/1), whereas Total Quality Recovery scale scores were likely higher in the first (p = .110, MD = 1.15, MBI = 83/16/1) and third (p = .082, MD = -.77, MBI = 70/29/1) repetitions compared with those in the PLA group. Blood lactate concentration [La+] levels showed no differences between groups in any of the repetitions (p > .05, unclear), and we observed an increase in 100-m times for both BJ and PLA (BJ: p = .014, MD = -1.51s; PLA: p = .029, MD = -1.57s) after the fifth repetition. Conclusion: No clear differences in performance were observed in a 6 × 100-m repeated sprint test by competitive swimmers when supplementing (or not) with BJ. However, there was a trend toward a better recovery between efforts and a better tolerance of fatigue when swimmers ingested BJ.

Recovery time variation during sprint interval training impacts amateur soccer players adaptations - a pilot study.

The objective of the present study was to investigate the selected performance adaptations of amateur soccer players to 2 different running-based sprint interval training (SIT) protocols with different recovery intervals and work-rest ratios (1:5 & 1:1). Twenty-three subjects (age 21.4 ± 1.1 years; height 175.4 ± 4.7 cm; body mass 69 ± 6.4 kg) participated in the study. Before the 6-weeks training period, participants completed 3-weeks of low-intensity training preparation. Subsequently, the pre-tests (anthropometric measurements, repeated sprint test [12 × 20-m with 30-s recovery intervals], Yo-YoIRT1 & Yo-YoIRT2 and treadmill VO2max test) were conducted. Thereafter, participants were randomly divided into 3 sub-groups (1 - SIT with 150 s recovery intervals [SIT150, n = 8]; 2 - SIT with 30 s recovery intervals [SIT30, n = 7]; and 3 - control group [CG, n = 8]). SIT150 and SIT30 training groups completed sprint interval training (2-days/week; 30-s all-out running, 6-10 repetition with 150 s recovery intervals for SIT150 and 30 s for SIT30 groups, respectively), a soccer match (1-day) and routine soccer training (3-days) per week. The CG attended only routine training sessions and the soccer-match (4-days). The study experiments and the trainings were conducted during off-season. Yo-YoIRT1, Yo-YoIRT2, and VO2max were significantly improved both in SIT30 and SIT150 (p < 0.05) groups. Yo-YoIRT1 and VO2max were also significantly improved in CG (p < 0.05). Both the SIT150 and SIT30 training were shown to improve Yo-YoIRT1, Yo-YoIRT2 and VO2max performance compared to the control group, nevertheless, SIT150 was more efficient in improving the Yo-YoIRT1, Yo-YoIRT2 than SIT30. The authors of this study suggest using SIT150 to induce more effective performance outputs in amateur soccer players.

Influence of Beetroot Supplementation on Oxygen Muscle Saturation of Semi-Professional Soccer Players Following a Repeated Sprint Test

Influence of Beetroot Supplementation on Oxygen Muscle Saturation of Semi-Professional Soccer Players Following a Repeated Sprint Test

A RELAÇÃO ENTRE RIGIDEZ DOS MEMBROS INFERIORES E ECONOMIA DE CORRIDA EM JOGADORES DE FUTEBOL INFANTIL

ABSTRACT Introduction Lower limb stiffness has been shown to be associated with running economy (RE) in adults, but this relationship in children remains unclear. Objectives The purpose of this study was to investigate the relationship between lower limb stiffness, RE, and repeated-sprint ability in child soccer players. Methods Twenty-eight male child soccer players (mean age 11.8 ± 0.9 years) participated in the study. RE was determined by measuring the steady-state oxygen uptake (ml/min/kg) at submaximal running speeds of 8 and 9 km/h. Vertical and leg stiffness were calculated from the flight and contact time data obtained during two submaximal running tests. Additionally, vertical stiffness was measured during the maximal and submaximal hopping tests. All participants performed the repeated sprint test consisting of 10 × 20-m all-out sprints interspersed with 20-s active recovery. Results During both submaximal running tests, vertical (r= –0.505 to –0.472) and leg stiffness (r= –0.484 to –0.459) were significantly correlated with RE (p&lt; 0.05). Maximal (r= –0.450) and submaximal hopping stiffness (r= –0.404) were significantly correlated with RE at 8 km/h (p&lt; 0.05). Maximal hopping stiffness was significantly correlated with the best sprint time (r= –0.439) and mean sprint time (r= –0.496) (p&lt; 0.05). Vertical (r= –0.592 to –0.433) and leg stiffness (r= –0.612 to –0.429) at 8 and 9 km/h and submaximal hopping stiffness (r= –0.394) were significantly correlated with the fatigue index (p&lt; 0.05). Conclusions Current findings indicate that the lower limb stiffness may be an important determinant of both RE and repeated-sprint ability in child soccer players. Level of Evidence II; Diagnostic Studies - Investigating a Diagnostic Test.

Changes in the Mechanical Properties of the Horizontal Force-Velocity Profile during a Repeated Sprint Test in Professional Soccer Players.

Seventeen first-division Chilean soccer players completed a repeated sprint protocol consisting of eight sprints of 30 m with 25-s pauses between repetitions. The behavior of HFVP variables in each attempt was recorded from video recordings and analysis in the MySprint® application. Differences (p < 0.05) were found between sprints in the following: time (T), starting from sprint 5 (F = 35.6; η2p = 0.69); theoretical maximum speed (V0), starting from sprint 4 (F = 29.3; η2p = 0.51); maximum power (PM), starting from sprint 5 (F = 17; η2p = 0.52); rate of decrease in force index produced at each step (DRF), starting from sprint 1 (F = 3.20; η2p = 0.17); and RF10, starting from sprint 1 (F = 15.5; η2p = 0.49). In comparison, F0 and RFpeak did not present any differences (p > 0.05). The HFVP variables more sensitive to the effects of fatigue induced by an RSA protocol are those associated with the production of force at high speeds, being V0, DRF, and Pmax, while those that contribute to the generation of force at the beginning of the sprint, F0 and RFpeak, do not present essential variations.

Predicting BMX Performance with Laboratory Measurements in Elite Riders

ABSTRACT In Bicycle Motocross (BMX) performance is determined by the riders’ sprint ability and power output. Therefore, descriptive and predictive performance assessments through laboratory and field tests are of interest. Twelve members of the Spanish BMX National Team performed 4 laboratory tests, including 1RM in squat, a Wingate test, a 5x6-s repeated sprint test (RST) and a force-velocity profile test. These tests were compared with the riders’ field performance using the best lap of a simulated BMX competition consisting of 6 all-out laps on a standard BMX track. Pearson’s correlation and linear regression analysis showed a significant association (p < 0.05) between the riders’ field performance and the 1RM (r = 0.84; R2 = 0.65), the peak power output in the RST (r = 0.87; R2 = 0.78) and the peak power, the mean power and the lactate production in the Wingate test (r = 0.68–0.77; R2 = 0.14–0.65), as well as maximal power from the force-velocity profile (r = 0.71; R2 = 0.53). The laboratory tests included in this study can show information about BMX riders’ performance, with the highest values for the peak power obtained in the repeated sprint test (78% of the variance in common).

Short-Term Creatine Supplementation and Repeated Sprint Ability-A Systematic Review and Meta-Analysis.

The aim of this study was to conduct a systematic review and meta-analysis of the effects of short-term creatine supplementation on repeated sprint ability. Fourteen studies met the inclusion criteria of adopting double-blind randomized placebo-controlled designs in which participants (age: 18-60years) completed a repeated sprint test (number of sprints: 4 < n ≤ 20; sprint duration: ≤10s; recovery duration: ≤90s) before and after supplementing with creatine or placebo for 3-7days in a dose of ∼20g/day. No exclusion restrictions were placed on the mode of exercise. Meta-analyses were completed using random-effects models, with effects on measures of peak power output, mean power output, and fatigue (performance decline) during each repeated sprint test presented as standardized mean difference (δ), and with effects on body mass and posttest blood lactate concentration presented as raw mean difference (D). Relative to placebo, creatine resulted in a significant increase in body mass (D = 0.79kg; p < .00001) and mean power output (δ = 0.61; p = .002). However, there was no effect of creatine on measures of peak power (δ = 0.41; p = .10), fatigue (δ = 0.08; p = .61), or posttest blood lactate concentration (D = 0.22L/min; p = .60). In conclusion, creatine supplementation may increase mean power output during repeated sprint tests, although the absence of corresponding effects on peak power and fatigue means that more research, with measurements of intramuscular creatine content, is necessary to confirm.

Low and Moderate Doses of Caffeinated Coffee Improve Repeated Sprint Performance in Female Team Sport Athletes.

Simple SummaryThe bulk of research on caffeine as an ergogenic aid has been on endurance performance, however there is evidence that caffeine can enhance short-term high-intensity performance. Caffeine may have an ergogenic impact during anaerobic exercise by facilitating central effects by antagonizing adenosine receptors, hence decreasing the detrimental effects of adenosine on neurotransmission, arousal, and pain perception. Caffeine intake also activates the central nervous system, which promotes alertness and concentration. Additionally, athletes typically consume coffee containing caffeine. To date, the bulk of study has focused on the administration of 3–9 mg/kg of anhydrous caffeine, as opposed to the readily accessible source of caffeine, coffee, and has mostly been conducted on males. Consequently, there is a dearth of study evaluating the ergogenic impact of caffeine on females, particularly when consuming alternative caffeine delivery methods, such as coffee. The current study is the first to investigate the effects of low (3 mg/kg) and moderate (6 mg/kg) doses of caffeine from coffee on repeated sprint performance in females.The aim of this study was to determine the effect of low and moderate doses of caffeine ingestion via caffeinated coffee on repeated sprint test (RST) and plasma catecholamine concentration in trained female team-sport athletes. In a randomized, double-blind, crossover design, 13 female team-sport athletes (VO2max: 48.7 ± 4 mL·kg·min−1) completed three RST trials, separated by 4-day, 60 min post-ingestion of either 3 mg·kg−1 (LCOF) or 6 mg·kg−1 (MCOF) or placebo (PLA). The RST consisted of 12 × 4 s sprints on a cycle ergometer interspersed with 20 s of active recovery. Blood lactate (BLa) and glucose (GLU) and epinephrine and norepinephrine concentrations were collected before and 60 min after coffee ingestion, and after RST. Heart rate (HR) and ratings of perceived exertion (RPE) were measured at the beginning of RST, and after the 6th and 12th sprints. Average peak power score during RST was significantly improved after LCOF (p = 0.016) and MCOF (p = 0.041) compared to PLA, but peak and mean power output of the individual sprints, and fatigue index were not different between trials (all p > 0.05). Epinephrine and norepinephrine concentrations were significantly higher before and after RST in LCOF and MCOF compared to PLA (all p < 0.05). BLa was also higher after RST in both LCOF and MCOF compared to PLA (p = 0.005). HR, RPE, and GLU were not different between conditions (p > 0.05). In conclusion, low and moderate dose of caffeine ingestion can enhance the average peak power score during repeated sprints. These findings partly support low and moderate doses of caffeine supplementation via coffee as a nutritional ergogenic aid for trained female team-sport players during repeated sprint exercise.

Evaluation of repeated sprint test protocols used in soccer with a global positioning system

Background and Study Aim. The aim of the research is to evaluate the 7x34.2 m Repeated Straight Sprint Test (RSST) and 7x34.2 m Repeated Change of Direction Sprint Test (RCST), which are used for improvement, measurement, and evaluation of repeated sprint ability, by using Global Positioning System (GPS).&#x0D; Material and Methods. Twenty-two professional soccer players participated in the research voluntarily. Internal and external load data were examined comparatively by using data as before and after the repeated sprint tests. External load data measured by 10 Hz GPS.&#x0D; Results. When the findings of the research are examined, it is seen that values of blood lactate concentrations which are taken after three and five minutes of the RCST are significantly higher than RSST protocol (p &lt; 0.001***, p = 0.042*, respectively). In the study, the value of lactate which is taken five minutes after the RSST was measured as 9.60 ± 2.65 mM, while the value which is taken three minutes after RCST was measured as 9.75 ± 2.51 mM. Nevertheless, whereas there was a difference between the two tests in terms of lactate values, no significant difference was found in terms of perceived exertion.&#x0D; Conclusions. As a conclusion, according to the analyzes made after the RCST and RSST, we can say that the internal and external load performances of the athletes were very different. It has been observed that coaches, athletes, and practitioners can use two different test protocols for different objectives according to the purposes they set.

Effects of Carbohydrate and Sodium Chloride Mouth Rinses on Repeated Sprint Performance

Aim: The purpose of this research is to examine the effects of oral rinsing of CHO and NaCl on repeated sprint performance in trained athletes.&#x0D; Methods: Fifteen trained athletes (5 women; 10 men) voluntarily participated in the repeated, single-blind, placebo-controlled and crossover design study. Athletes came to the laboratory with a night fasting four times with an interval of at least 48 hours and participated in the repeated sprint test (10 sec × 6, 40 sec intervals) after 30 minutes of endurance exercise (70% maxVO2). At the 0th, 10th, 20th and 30th minutes of the endurance exercise, it was requested to MR with CHO (6.4% maltodextrin), sodium chloride (6.4%) solution and water (placebo) or no rinsing (control).&#x0D; Results: As a result of the analyzes performed with 3 × 4 ANOVA, the power output variables obtained by repeated sprint performance [peak power, average power, minimum power (W, W/kg) and fatigue index (%)] and fatigue variables (heart rate, blood lactate level and rate of perceived exertion) between sessions were not found to be significantly different.&#x0D; Conclusion From the obtained results, it may be concluded that the method and stimuli used in this study seem insufficient to affect the outcome variables of physical performance.

Effects of a Short-Term Heat Acclimation Protocol in Elite Amateur Boxers

Stone, BL, Ashley, JD, Skinner, RM, Polanco, JP, Walters, MT, Schilling, BK, and Kellawan, JM. Effects of a short-term heat acclimation protocol in elite amateur boxers. J Strength Cond Res 36(7): 1966-1971, 2022-Boxing requires proficient technical and tactical skills coupled with high levels of physiological capacity. Although heat and humidity negatively affect acute exercise performance, short-term exercise training in hot and humid environments can lead to physiological adaptations that enhance exercise performance in both hot and thermoneutral conditions. In highly trained endurance athletes, exercise-induced acclimation can occur in as little as 5 days (known as short-term heat acclimation [STHA]). However, the impact of a 5-day heat acclimation (5-DayHA) in combat athletes, such as elite amateur boxers, is unknown. The aim of the present investigation was to determine whether a 5-DayHA improves aerobic performance in a thermoneutral environment and causes positive physiological adaptations in elite boxers. Seven elite amateur boxers underwent a 5-DayHA protocol, consisting of 60-minute exercise sessions in an environmental chamber at 32 °C and 70% relative humidity. Repeat sprint test (RST) evaluated aerobic performance in a thermoneutral environment 24 hours before and after the 5-DayHA. Presession and postsession hydration status (urine specific gravity) and body mass were assessed. After a 5-DayHA period, boxers significantly improved RST performance (13 ± 7 to 19 ± 7 sprints, d = 0.92, p = 0.03) but not pre-exercise hydration status (1.02 ± 0.01 to 1.01 ± 0.01, d = 0.82, p = 0.07). Therefore, these findings suggest 5-DayHA enhances aerobic performance in elite-level amateur boxers and may provide a viable training option for elite combat athletes.