Sprint Running Research Articles

Cross Sectional Study About Intra-Individual and Inter-Individual Variability of Subjective Effort in Submaximal Sprint Running in Collegiate Male Sprinters

Background: Although subjective exercise intensity is widely used to monitor training load in athletes, the reliability of subjective effort (SE) during high-intensity sprint running has not yet been established. Objectives: This study aimed to examine the intra-individual and inter-individual variability in sprint running performance at different SE levels. Methods: Eighteen male collegiate sprinters participated in the study. We measured 60 m sprint running performance at four SE levels (60% SE, 80% SE, 90% SE, and 100% SE) every day for 5 days. The coefficient of variation (CV) of each participant’s 5-day performance (60 m sprint time (60T) and 40 - 50 m interval average speed (SP)) was calculated to assess the intra-individual variability of SE. A repeated measures ANOVA was used to compare 60 T, SP, and the CVs of 60 T and SP across the different SE levels. Results: The SP ratios of each submaximal sprint (60% SE, 80% SE, 90% SE) to the maximal sprint (100% SE) were 89.72 ± 1.62%, 95.50 ± 1.08%, and 98.11 ± 0.56%, respectively. The inter-individual variation at each SE level for 60T was inversely related to the SE level (60% SE: 3.25%, 80% SE: 2.31%, 90% SE: 2.06%, and 100% SE: 1.54%). Significant differences were found in the intra-individual variability (CV) of 60 T between 60% SE (2.22 ± 0.35%) and 90% SE (1.42 ± 0.22%), 60% SE and 100% SE (1.40 ± 0.30%), 80% SE (1.95 ± 0.32%) and 90% SE, and between 80% SE and 100% SE (P < 0.05). Conclusions: Intra- and inter-individual variation at all SE levels were below 5%, indicating that SE is a reliable indicator of sprint running intensity. However, the lower the SE, the greater the variability, suggesting SE is most suitable for higher-intensity sprint running.

Repeated sprint training in hypoxia and repeated long sprint ability in highly trained sprint runners

Repeated sprint training in hypoxia and repeated long sprint ability in highly trained sprint runners

Enhancing Sports Injury Risk Assessment in Soccer Through Machine Learning and Training Load Analysis.

Sports injuries pose significant challenges in athlete welfare and team dynamics, particularly in high-intensity sports like soccer. This study used machine learning algorithms to assess non-contact injury risk in professional male soccer players from physiological and mechanical load variables. Twenty-five professional male soccer players with a first-time, non-contact muscle injury were included in this study. Recordings of external load (speed, distance, and acceleration/deceleration data) and internal load (heart rate) were obtained during all training sessions and official matches over a 4-year period. Machine learning model training and evaluation features were calculated for each of nine different metrics for a 28-day period prior to the injury and an equal-length baseline epoch. The acute surge in the values of each workload metric was quantified by the deviation of maximum values from the average, while the variations of cumulative workload over the last four weeks preceding injury were also calculated. Seven features were selected by the model as prominent estimators of injury incidence. Three of the features concerned acute load deviations (number of sprints, training load score-incorporating heart rate and muscle load- and time of heart rate at the 90-100% of maximum). The four cumulative load features were (total distance, high speed and sprint running distance and training load score). The accuracy of the muscle injury risk assessment model was 0.78, with a sensitivity of 0.73 and specificity of 0.85. Our model achieved high performance in injury risk detection using a limited number of training load variables. The inclusion, for the first time, of heart rate related variables in an injury risk assessment model highlights the importance of physiological overload as a contributor to muscle injuries in soccer. By identifying the important parameters, coaches may prevent muscle injuries by controlling surges of training load during training and competition.

Assessing pre-season workload variation in professional rugby union players by comparing three acute:Chronic workload ratio models based on playing positions

Quantifying the pre-season workload of professional Rugby Union players, in relation to their respective positions not only provides crucial insights into their physical demands and training needs but also underscores the significance of the acute:chronic workload ratio (ACWR) in assessing workload. However, given the diversity in ACWR calculation methods, their applicability requires further exploration. As a result, this study aims to analyze the workload depending on the player's positions and to compare three ACWR calculation methods. Fifty-seven players were categorized into five groups based on their playing positions: tight five (T5), third-row (3R), number nine (N9), center, and third line defense (3L). The coupled and uncoupled rolling averages (RA), as well as the exponentially weighted moving average ACWR method, were employed to compute measures derived from GPS data. Changes throughout the pre-season were assessed using the one-way and two-way analysis of variance. The results revealed that N9 covered significantly greater distances and exhibited higher player load compared to T5 and 3L [p < 0.05, effect size (ES) = 0.16–0.68]. Additionally, 3L players displayed the highest workload across various measures, including counts of accelerations and decelerations (>2.5 m s−2), accelerations (>2.5 m s−2), acceleration distance (>2 m s−2), high-speed running (>15 km h−1), very high-speed running (>21 km h−1, VSHR), sprint running (>25 km h−1, SR) distance. When using coupled RA ACWR method, centers exposed significantly greater values to T5 (p < 0.05, ES = 0.8) and 3R (p < 0.05, ES = 0.83). Moreover, centers exhibited greater (p < 0.05, ES = 0.67–0.91) uncoupled RA ACWR values for VHSR and SR than T5 and 3R. When comparing the three ACWR methods, although significant differences emerged in some specific cases, the ES were all small (0–0.56). In light of these findings, training should be customized to the characteristics of players in different playing positions and the three ACWR calculation methods can be considered as equally effective approaches.

Acute Effects of Dynamic Stretching on Functional Performance in Non-Athlete Young Adults

Abstract Background: Warming up is an activity carried out before exercise or competition to optimize performance. Dynamic stretching is a type of stretching that is applied as a part of warming up. Previous study showed that dynamic stretching had an acute effect on functional performance in athletes. But, acute effects on functional performance in non athletes have not been studied yet. Aim: To prove that the addition of dynamic stretching during warming up has an acute effect on functional performance. Material and Methods: This study uses an experimental method of randomized controlled trial post test design on 44 physically active young adults in non athlete level who were divided into two research groups. The intervention group completed 5 minute jogging and dynamic stretching whereas the control group completed 5 minute jogging without stretching then each group performed a modified 20-m sprint run test and triple hop for distance test. Result: There is no statistical significant difference in comparison between groups. On speed showed that p values = 0.845 (p&gt; 0.05) and on power showed that p values = 0.366 (p&gt;0.05). Conclusion: Addition of dynamic stretching during warming up has not been proven to have a better acute effect on speed and power in non-athlete young adults.Keywords: Dynamic Stretching, Functional Performance, Warming Up

Physical Fitness and Exercise Performance of Transgender Women.

In spite of the evolving participation of transgender adults in exercise and sports, research investigating the physical fitness of transgender women remains scarce in the scientific literature. In this cross-sectional study, a variety of reference-standard measures of physical fitness of transgender women who had undergone gender-affirming orchiectomy (30 ± 4 years; n = 15) and who had not (27 ± 4 years: n = 15) were compared with reference males (28 ± 5 years; n = 15) and reference females (29 ± 5 years; n = 15) who were matched for age and estimated physical activity level. Transgender women had been undergoing feminizing gender-affirming therapy for 8-10 years. Height and lean mass of arms, legs, and trunk (measured via DXA) of transgender women were greater than those of reference females but lower than those of reference males (all p < 0.05). No significant differences were in isokinetic muscular torque found between reference females and transgender women. Both absolute and relative measures of maximal oxygen consumption were greater in reference males than in reference females and transgender women (all p < 0.05) with no significant difference between the latter two groups. Reference males had greater peak Wingate anaerobic power (expressed in both absolute and relative to body weight), countermovement jump, and squat jump than reference females and transgender women (all p < 0.05). There were no significant differences in anaerobic power between reference females and transgender women. The results on the field tests, including agility T-test and sprint running acceleration, were consistent with the anaerobic power tests. There were no statistical differences in any of the physical fitness measures between transgender women with and without orchiectomy. Transgender women demonstrated similar levels of reference-standard measures of physical fitness to females that were significantly lower than males.

Increased resting lactate levels and reduced carbohydrate intake cause νLa.max underestimation by reducing net lactate accumulation-A pilot study in young adults.

Modulation of testing conditions such as resting lactate (Larest) levels or carbohydrate intake may affect the calculation of the maximal glycolytic rate (νLa.max). To evaluate the impact of elevated Larest as well as reduced and increased carbohydrate availability on νLa.max in running sprints (RST), twenty-one participants completed five 15-s RST tests on a running track under five different conditions: (I). baseline: Larest ≤1.5 mmol·L-1; (II). Lactate+: Larest ≥2.5 mmol·L-1; (III). CHO-: carbohydrate intake: ≤ 1 g·kg-1 BW d-1 for 3 days; (IV). CHO+: carbohydrate intake: ≥ 9 g·kg-1 BW d-1 for one day; and (V). acuteCHO: 500 mL glucose containing beverage consumed before RST. νLa.max was significantly reduced in lactate+ and CHO- conditions compared to the baseline RST, due to a reduction in the arithmetic mean delta (∆) between Lapeak and Larest lactate concentration (Lapeak, mmol · L-1). AcuteCHO led to an increase in Larest compared to baseline, CHO- and CHO+ with a high interindividual variability but did not significantly reduce νLa.max. Therefore, avoiding low carbohydrate nutrition before νLa.max testing, along with carefully adjusting Larest to below ≤1.5 mmol·L-1, is crucial to prevent the unintentional underestimation of νLa.max.

Time to retire the raw analysis of individual responses

This letter critiques the data analysis of a study investigating peak oxygen uptake responses to cycling and running sprint interval training (Digby et al., 2023 J Strength Cond Res, 37(4), e313-e316). While the study effectively demonstrates the specificity principle in the context of sprint interval training, concerns arise regarding the methodology used to categorise participants as responders or non-responders. The letter highlights the disregard for the recommendations of a number of academics advocating for specific experimental designs and statistical analyses to examine inter-individual variability. Furthermore, the reliability of within-individual adaptive responses to training and the potential impact of measurement errors and biological fluctuations are considered. It is suggested that the (non-)responder categorisation adds nothing to the main findings of the study and should be avoided. The importance of using appropriate experimental designs and statistical analyses when investigating inter-individual variability is emphasised. An open-source beta-version simulator is introduced as an educational resource to demonstrate the limitations inherent in the responder counting approach.

The Influence of the Playing Surface on Workload Response in Spanish Professional Male Soccer Players.

This study aimed to quantify the influence of the playing surface on workload-related variables (i.e., external load, Rate of perceived exertion (RPE), and mental load) in training sessions with a Spanish professional soccer team. Twenty professional male players from the same soccer team were involved. A total of thirty training sessions related to the preseason period were included. All the players completed training sessions on three playing surfaces: natural turf of poor quality, natural turf of high quality, and third-generation artificial turf. Monitoring during sessions involved assessing internal load (i.e., RPE and mental load) via self-reported questionnaires, and external load using Global Positioning System devices. Linear mixed models showed that RPE was significantly higher on natural turf of high quality than on natural turf of poor quality (p < 0.001). Total distance, relative total distance, the number of accelerations, decelerations, and high metabolic load distance were significantly lower on third-generation artificial turf compared to natural turf of poor quality (p < 0.001) and high quality (p < 0.001). In addition, high-speed running, sprint running distances, and the number of sprints reached higher values on third-generation artificial turf compared to the other two playing surfaces. These findings highlight the need for coaches to consider the type of training surface in soccer to optimize training load planning and prevent injuries.

Running sprint force-velocity-power profile obtained with a low-cost and low frame rate acquisition video technique: reliability and concurrent validity

ABSTRACT The Force-velocity (F-v) and Power-velocity (P-v) relationships quantify athlete’s horizontal force production capacities during sprinting. Efforts are underway to enhance ecological validity for practitioners and sports coaches. This study provides detailed data comparison of a low frames per second setup (30 Hz; FPSlow) with splits from a high FPS camera to derive F-v and P-v relationships. Sixty-six sprints performed by 11 university track and field athletes (6 male, 5 female) were evaluated. Data were recorded using FPSlow, photocells, and a high-speed camera (240 Hz; MySprint). In the FPSlow setup, bias was 0.17s, and Limits of agreement was 0.09s compared to photocells. ICC was 1.00, and the coefficient of variation (CV) was 1.0% [0.8–1.1%]. Time acquisition comparison between MySprint and FPSlow setups revealed high consistency (ICC = 0.99) and low CV (2.9% [2.8–3.1%]). F-v profile variables exhibited biases from trivial to small, with ICC ranging from moderate to nearly perfect. CV ranged from 2.7% to 11.8%, and improved using the average of three sprints (CV between 1.8% and 8.6%). The ‘simple method’ applied to data from the low FPS video setup yielded kinetic and kinematic parameters comparable to those obtained by the validated previous method and photocells.

Effect of 6-Week Sprint Training on Long-Distance Running Performance in Highly Trained Runners.

Long-distance running performance has been reported to be associated with sprint performance in highly trained distance runners. Therefore, we hypothesized that sprint training could enhance distance running and sprint performance in long-distance runners. This study examined the effect of 6-week sprint training on long-distance running and sprint performance in highly trained distance runners. Nineteen college runners were divided into control (n = 8) and training (n = 11) groups. Participants in the training group performed 12 sprint training sessions in 6weeks, while those in the control group performed 12 distance training sessions. Before and after the interventions, maximal oxygen uptake (V˙O2max), O2 cost during submaximal running (290m·min-1 and 310m·min-1 of running velocity), and time to exhaustion (starting at 290m·min-1 and increased 10m·min-1 every minute) were assessed on a treadmill. Additionally, the 100-m and 400-m sprinting times and 3000-m running time were determined on an all-weather track. In the control group, no measurements significantly changed after the intervention. In the training group, the time to exhaustion, 100-m and 400-m sprinting times, and 3000-m running time improved significantly, while V˙O2max and O2 cost did not change. These results showed that 6-week sprint training improved both sprint and long-distance running performance in highly trained distance runners without a change in aerobic capacity. Improvement in the time to exhaustion without a change in V˙O2max suggests that the enhancement of long-distance running performance could be attributable to improved anaerobic capacity.

Muscle morphological changes and enhanced sprint running performance: A 1-year observational study of well-trained sprinters.

Numerous cross-sectional studies have attempted to identify the muscle morphology required to achieve high sprint velocity. Our longitudinal study addressed an unanswered question of cross-sectional studies: whether hypertrophy of the individual trunk and thigh muscles induced by daily training (e.g., sprint, jump, and resistance training) is linked to an improvement in sprint performance within well-trained sprinters. Twenty-three collegiate male sprinters (100-m best time of 11.36±0.44s) completed their daily training for 1year without our intervention. Before and after the observation period, the sprint velocities at 0-100m, 0-10m, and 50-60m intervals were measured using timing gates. The volumes of 14 trunk and thigh muscles were measured using magnetic resonance imaging. Muscle volumes were normalized to the participants' body mass at each time point. Sprint velocities increased at the 0-100m (p<0.001), 0-10m (p=0.019), and 50-60m (p=0.018) intervals after the observation period. The relative volumes of the tensor fasciae latae, sartorius, biceps femoris long head, biceps femoris short head, semitendinosus, and iliacus were increased (all p<0.050). Among the hypertrophied muscles, only the change in the relative volume of the semitendinosus was positively correlated with the change in sprint velocity at the 50-60m interval (p=0.018 and ρ=0.591). These findings suggest that semitendinosus hypertrophy seems to be associated with sprint performance improvement within well-trained sprinters during the maximal velocity phase.

Sprint Acceleration Mechanical Outputs and Lower Limb Injuries: A Follow-Up of Sprint, Jumps and Combined Events Athletes during an Athletics Season

Problem: We aimed to explore the potential association between sprint running horizontal force production capacities (the theoretical maximum horizontal force that the lower limbs can produce at zero velocity: FH0, and the theoretical maximum velocity until which they can produce force (velocity at zero force): v0 ) and occurrence of lower limb injuries (LLI) in athletics (track and field) athletes through a season. Methods: We performed a prospective cohort study with data collection of FH0 and v0 and their week-to-week changes (dFH0 and dv0 , respectively) and LLI in 16 athletes practicing sprints, jumps or combined events in the same training group during the 2021/2022 season (37 weeks). We performed a multivariable binomial logistic regression with LLI (yes/no) as the dependent variable, and FH0 and v0 , dFH0 and dv0 as explanatory variables, adjusted for individual athletes and LLI during the previous week (yes/no). Risk indicators were presented as odd ratios (OR) and 95% confidence intervals (95% CI). › Results: The multivariable binomial logistic regression showed that a higher FH0 was associated with lower LLI risk (OR=0.12 (95%CI: 0.00-0.89). Conclusion: Lower FH0 was associated with higher risk of sustaining a new lower limb injury during the next week. Although caution should be taken on these preliminary results (e.g., small athletes’ sample, missing measurements, few confounding factors included), monitoring the FH0 could be one additional relevant approach to detect LLI in athletics.

The Effects of Crossfit Training Program on Promoting Physical Fitness Towards a Training Program for Guangdong University Basketball League Players

In this paper, 20 basketball players from each of the three universities who participated in the Guangdong University Basketball League, total 60 persons, were used as experimental subjects. Each university was divided into an experimental group of 10 players and a control group of 10 players for a 12-week comparison experiment. The experimental group was trained using CrossFit program and the control group was trained using traditional physical training methods. The six indexes of body shape, strength, speed, endurance, flexibility and agility were taken as the physical fitness evaluation indexes, and the corresponding test items were body fat percentage, standing long jump, bench press, squat, deadliftl, 3/4 full-court sprint run, 15×17 folding run, 3000 meters run, seated body flexion, and T-word agility test, a total of 10 test items. The data collected before and after the 12 weeks of training were statistically and analytically analysed through the use of EXCEL and SPSS26.0 software. To explore the effects of CrossFit training on athletes' physical fitness relative to traditional physical training. The purpose of the study is to combine CrossFit training with the characteristics of basketball, arrange and design a targeted training program, and help athletes of the Guangdong University Basketball League to improve their physical fitness and performance on the basketball court through scientific training means and methods. Conclusion: Before the CrossFit training program, there is no significant difference in the physical fitness index scores of body shape, strength, speed, endurance, flexibility and sensitivity between the control group and the experimental group, There is no significant difference between the physical status of the control group and the experimental group before the CrossFit training program; After the CrossFit training program, there are significant differences between the control group and the experimental group in terms of body shape, strength, speed, endurance. There were no significant differences in flexibility and sensitivity, but the experimental group improved more than the control group. There is a significant difference between the physical status of the control group and the experimental group after the CrossFit training program; There is no significant difference in the physical status of the control group before and after the experiment. There is a significant difference in the physical status of the experimental group before and after CrossFit training. CrossFit training program is more suitable for improving the physical fitness of college basketball players in Guangdong Province.

Hamstrings Hypertrophy Is Specific to the Training Exercise: Nordic Hamstring versus Lengthened State Eccentric Training.

The hamstring muscles play a crucial role in sprint running but are also highly susceptible to strain injuries, particularly within the biceps femoris long head (BFlh). This study compared the adaptations in muscle size and strength of the knee flexors, as well as BFlh muscle and aponeurosis size, after two eccentrically focused knee flexion training regimes: Nordic hamstring training (NHT) vs lengthened state eccentric training (LSET, isoinertial weight stack resistance in an accentuated hip-flexed position) vs habitual activity (no training controls: CON). Forty-two healthy young males completed 34 sessions of NHT or LSET over 12 wk or served as CON ( n = 14/group). Magnetic resonance imaging-measured muscle volume of seven individual knee flexors and BFlh aponeurosis area, and maximum knee flexion torque during eccentric, concentric, and isometric contractions were assessed pre- and post-training. LSET induced greater increases in hamstrings (+18% vs +11%) and BFlh (+19% vs +5%) muscle volumes and BFlh aponeurosis area (+9% vs +3%) than NHT (all P ≤ 0.001), with no changes after CON. There were distinctly different patterns of hypertrophy between the two training regimes, largely due to the functional role of the muscles; LSET was more effective for increasing the size of knee flexors that also extend the hip (2.2-fold vs NHT), whereas NHT increased the size of knee flexors that do not extend the hip (1.9-fold vs LSET; both P ≤ 0.001). Changes in maximum eccentric torque differed only between LSET and CON (+17% vs +4%; P = 0.009), with NHT (+11%) inbetween. These results suggest that LSET is superior to NHT in inducing overall hamstrings and BFlh hypertrophy, potentially contributing to better sprint performance improvements and protection against hamstring strain injuries than NHT.

Impact of Anaerobic Exercise Integrated Into Regular Training on Experienced Judo Athletes: Running Vs. Repetitive Throws.

Kamandulis, S, Dudėnienė, L, Snieckus, A, Kniubaite, A, Mickevicius, M, Lukonaitiene, I, Venckunas, T, Stasiule, L, and Stasiulis, A. Impact of anaerobic exercise integrated into regular training on experienced judo athletes: running vs. repetitive throws. J Strength Cond Res 38(9): e489-e495, 2024-Anaerobic training in high-level athletes is of considerable interest to practitioners aiming to optimize performance. This study compared the impact of interval anaerobic training (IAT) sessions consisting of either high-intensity running or throwing that were performed twice a week together with regular judo training on the anaerobic and aerobic performance of experienced judo athletes. Employing a repeated-measures, counterbalancing, research design, 12 national team judo athletes (7 women and 5 men; mean age, 20.4 ± 0.95 years; mean judo training experience, 13.4 ± 1.4 years; competitive level, black belt first and second Dan) performed each IAT modality for 6 weeks, for a full training cycle of 12 weeks. Assessments of their anaerobic fitness (Cunningham and Faulkner Anaerobic Treadmill Test), sport-specific anaerobic fitness (Special Judo Fitness Test [SJFT]), and aerobic capacity (maximal incremental treadmill running test) were performed before, after 6 weeks, and after 12 weeks of training. The uphill running performance improved by 13.1% over the 12-week period ( p = 0.047). Simultaneously, there was a 9.0% improvement in the SJFT index and a 6.9% increase in the number of throws ( p = 0.011 and p = 0.017, respectively). Although a trend for throwing drills being more effective than interval sprint running was observed, the interaction effect lacked statistical significance ( p = 0.074). Moreover, no substantial changes were noted in aerobic endurance markers. In conclusion, this study suggests that incorporating specific and nonspecific high-intensity drills into a routine training regimen may enhance anaerobic capacity among well-trained judo athletes, potentially leading to favorable competitive outcomes.

Efforts to Improve Student Learning Outcomes Sprint Running Through Traditional Games (Gobak Sodor)

This study aims to determine the increase in student learning outcomes Sprint Running through traditional games (Gobak Sodor). This research was carried out in the 2022/2023 school year. The form of this research was classroom action research. The research subjects were 37 students in class VIII F of MTs Al-Muttaqin Pekanbaru. This research technique is total sampling. The data analysis technique uses a performance test, namely doing Sprint Running practice, then the test results are assessed. From the implementation of the first cycle, the results were 26 students who achieved the KKM score (70%) and 11 students who had not reached the KKM score (30%), followed by the implementation of the second cycle, the results increased with a total of 37 students achieving the KKM score (100%). Thus it can be concluded that there is an increase in student learning outcomes in sprinting through traditional games (gobak sodor) at Mts Al-Muttaqin Pekanbaru with an increase of (100%).

Influence of the External Workload on Calf Muscle Strain Injuries in Professional Football Players: A Pilot Study.

The influence of external workload variables on the development of calf muscle strainsin football players has not been previously explored. Overloaded players would have an increased risk of calf muscle strain injury. Prospective observational study. Level 4. A total of 41 professional football players from 1 team were monitored for 2 consecutive seasons. Total distance covered (TD), and distances covered at high-intensity running, high sprint running, low (LACC) and high (HACC) acceleration, low (LDEC) and high (HDEC) deceleration, and at high metabolic load distance (HMLD) were monitored with GPS units. Accumulated players' external workload in the week before injury was compared with the weekly mean value of the 6 weeks before injury occurred for each player. Ten players (24.3%) suffered 16 calf muscle strain injuries (3.1 injuries per 1000 hours of match play; 0.5 injuries per 1000 hours of training exposure). Players with a calf muscle injury were older (p = 0.03), with higher body weight (p = 0.01) and height (p = 0.03). Injured players displayed substantially higher total training volume (p < 0.01), TD (p < 0.01), LACC (p < 0.01), LDEC (p < 0.01), HACC (p < 0.01), HDEC (p < 0.01), and HMLD (p = 0.03) in the week before injury, in comparison with the mean values of these variables in the 6 weeks before injury. A week with a higher-than-habitual external workload might increase the risk of calf muscle strain injury in professional football players. Calf muscle injuries were preceded by a week with unusually high workloads associated with accelerating and decelerating distances and higher training volumes. Monitoring external workload indicators may be helpful in determine players with a higher risk of calf muscle strain injury due to excessive workload during training/competition.

Effects of a 6-Week Repeated-Sprint Training With Voluntary Hypoventilation at Low and High Lung Volume on Repeated-Sprint Ability in Female Soccer Players.

To investigate the effects of repeated-sprint training with voluntary hypoventilation at low (RSH-VHL) and high (RS-VHH) lung volume on repeated-sprint ability (RSA) in female athletes. Over a 6-week period, 24 female soccer players completed 12 sessions of repeated 30-m running sprints with end-expiratory breath holding (RSH-VHL, n = 8), end-inspiratory breath holding (RS-VHH, n = 8), or unrestricted breathing (RS-URB, n = 8). Before and after training, a running RSA test consisting of performing 30-m all-out sprints until exhaustion was implemented. From before to after training, the number of sprints completed during the RSA test was increased in both RSH-VHL (19.3 [0.9] vs 22.6 [0.9]; P < .01) and RS-VHH (19.3 [1.5] vs 20.5 [1.7]; P < .01) but not in RS-URB (19.4 [1.3] vs 19.5 [1.7]; P = .67). The mean velocity and the percentage decrement score calculated over sprints 1 to 17 were, respectively, higher (82.2% [1.8%] vs 84.6% [2.1%] of maximal velocity) and lower (23.7% [3.1%] vs 19.4% [3.2%]) in RSH-VHL (P < .01), whereas they remained unchanged in RS-VHH and RS-URB. The mean arterial oxygen saturation recorded during training at the end of the sprints was lower in RSH-VHL (92.1% [0.4%]) than in RS-VHH (97.3% [0.1%]) and RS-URB (97.8% [0.1%]). This study shows that female athletes can benefit from the RSH-VHL intervention to improve RSA. The performance gains may have been limited by the short sprinting distance with end-expiratory breath holding, which provoked only moderate hypoxemia. The increase in the number of sprints in RS-VHH seems to show that factors other than hypoxia may have played a role in RSA improvement.

Longitudinal study of three-dimensional pelvic behaviour in maximal sprint running

The kinematics and kinetics of pelvis are associated with sprint performance. In this study, we aimed to investigate the longitudinal changes in the kinematics and kinetics of the pelvis in response to increasing sprinting velocity. Nine male sprinters performed 60 m regular sprints starting from a crouching start position, once a year. A three-dimensional motion analysis was performed to longitudinally investigate the changes in the pelvic movements and force exertion characteristics during sprinting. Sprinting velocity was significantly higher in the post-test than the pre-test. Step frequency was significantly higher in the post-test than the pre-test. The pelvic anterior/posterior tilt angle at stance leg touch-down, stance leg toe-off, and free leg touch-down were significantly smaller in the post-test than the pre-test. The thigh angle of the stance leg at stance leg toe-off and free leg touch-down were significantly smaller in the post-test than in the pre-test. The integrated contributory component of the lumbosacral joint torsion angular impulse during the stance phase was significantly greater in the post-test than the pre-test. This study provided new insights into the longitudinal evaluation of sprint performance in the transverse plane, focusing on pelvic movement and force exertion characteristics.