Sprint Group Research Articles

Effect of plyometric and sprint training on repeated sprint and vertical jump capacities in volleyball players aged 11 to 14 Years: A longitudinal study

In adults, plyometric training can positively influence repeated sprint ability, and sprint training can influence vertical jump capacity. However, in children and adolescents, such influences are not yet clear. The aim of this study was to evaluate the effect of plyometric training on repeated sprinting ability and the effect of repeated sprint training on vertical jump performance in young volleyball players of both sexes. Longitudinal study with a sample of 30 adolescents, aged 11 to 14 years. The volunteers were divided into a control group, a plyometric training group, and a sprint training group, and they underwent six weeks of training (two sessions per week). Their repeated sprint ability was assessed using photocell technology, and their vertical jump capacity was evaluated on a platform with an interruption system. There was a significant difference in pre- and post-training within the groups. The Sprint Group showed improvement in the best sprint (p=0.023) and worst sprint (p=0.10). The group that performed additional plyometric training also showed improvement in the best sprint (p=0.004) and worst sprint (p=0.008). As for the countermovement vertical jump, the Sprint Group showed a significant difference from pre-training (5.04±0.67) to post-training (5.37±0.54). The repeated sprint training proved to be effective in improving both repeated sprint and vertical jump capabilities.

Response of skin temperature, blood ammonia and lactate during incremental exercise until exhaustion in elite athletes

The study aimed to evaluate the lower limb skin temperature (Tsk) and blood concentrations of lactate (LA) and ammonia (NH3) during exercise and recovery. Eleven elite sprint athletes (25 ± 3.4 yrs) and 11 elite endurance athletes (24.45 ± 5.4 yrs) performed an incremental running test until exhaustion. Body composition was estimated using the DXA method. Thermograms of the anterior and posterior surfaces of the lower limbs were recorded at rest, before each test stage (every 3 min, starting from 10 km h−1 and increasing by 2 km h−1), and in the 5th, 10th, 15th, 20th, and 30th minute of recovery. Endurance athletes had a higher maximum oxygen uptake than sprint athletes (5.0 ± 0.7 vs 4.3 ± 0.4 l·kg−1, p = 0.018), lower percentage of lean content (79 ± 2 vs 83 ± 2%, p < 0.001), and a higher percentage of fat content in the lower limbs (17 ± 2 vs 12 ± 2%, p < 0.001). In both groups, a significant decrease in Tsk was observed compared to resting value (endurance athletes—31.5 ± 0.6 °C; sprint athletes—32.3 ± 0.6 °C), during exercise (p < 0.001) and rewarming during recovery (p < 0.001). However, endurance athletes had a lower Tsk than sprint athletes at the exhaustion point (30.0 ± 1.1 vs 31.6 ± 0.8 °C, p < 0.05) and the pattern of change in Tsk differed between groups (p < 0.001). Tsk in the endurance athletes group decreased throughout the exercise protocol and returned more rapidly to initial values during recovery, while Tsk in the sprint group stabilised between moderate intensity and exhaustion, recovering more slowly after exercise. Both LA (endurance athletes—max 10.2 ± 1.5; sprint athletes—max 10.1 ± 1.4 mmol⋅L−1, p < 0.001) and NH3 (endurance athletes—max 75.6 ± 11.5; sprint athletes—max 76.7 ± 9.0 mmol⋅L−1, p < 0.001) increased during exercise and decreased during recovery (p < 0.001). During exercise, lower levels and slower increases in LA were observed during exercise in the endurance athletes’ group (p < 0.05). A negative correlation was revealed between Tsk and fat percentage (r = −0.43 to −0.71, p < 0.05). Tsk was positively correlated with LA during recovery (r = 0.43 to 0.48, p < 0.05), and negatively during recovery (r = −0.45 to −0.54, p < 0.05). Differences between groups in maximum aerobic capacity, the pattern of change in Tsk, and the correlation between Tsk and LA suggest that individuals who decrease less Tsk during exercise and higher Tsk during recovery are those with better aerobic capacity. In addition, athletes with less body fat dissipate heat from their tissues more efficiently.

Abstract 12210: Repeated Systolic Blood Pressure Measures During Intensive Treatment Show a Loss Of Protective Effect Over Time. A Secondary Analysis of the SPRINT Trial

Introduction: The SPRINT trial showed a 25% reduction in the primary outcome with SBP intensive treatment using Cox proportional risk analysis. A recent secondary analysis by the SPRINT group assessed the post-trial maintenance of this protection by considering repeated SBP measurements and using a mixed linear regression model. They found that the intervention lost its protective effect post-trial, possibly due to the loss of intensive blood pressure control. Could this loss of protective effect also be found during the clinical trial, when considering repeated measurements of systolic blood pressure in the analysis? Methods: Secondary analysis of the SPRINT study database included 9,068 patients with repeated measures of SBP and complete baseline information. Cox proportional hazards and mixed linear models were used to analyze the primary endpoint and repeated SBP measures, respectively. A Cumulative Joint Model Analysis was conducted to combine the direct and indirect effects of the intervention on the primary outcome. R Studio V12.0 software was used for the analyses. Results: The protective effect is lost during the trial, both in the total population (3.4 years) as well as in subgroups such as women (1.1 years), patients with CVD (1.3 years), CKD (1.3 years), black patients (1.8 years), younger than 75 years (2.1 years) and in patients who present serious adverse events (3.4 years) compared to those who do not present SAEs (4.2 years). Beyond the loss of blood pressure control, other factors such as cumulative BP, adverse events, and the increase in SBP variability could be considered. Conclusions: Including repeated measures of SBP revealed a loss of protective effect in the intervention during the trial and generated Simpson's paradox. This highlights the need to consider alternative statistical methods in clinical trial analysis beyond Cox proportional hazard analysis for a comprehensive perspective on intervention efficacy.

Effects of sprint versus strength training on risk factors for hamstring injury in football players.

This study aimed to compare the effects of in-season sprint training vs. Nordic hamstring exercise (NHE) training on risk factors for hamstring strain injuries (HSI). Eighteen male university football players (20.9±2.5 years; 181±7 cm; 75.8±9.1 kg; 15.2±3.5% of body fat) were randomly allocated to a sprint group or NHE group. They completed baseline isokinetic strength and sprint mechanics assessments prior to their assigned intervention performed twice weekly for 4-weeks, before post-testing. A mixed design ANOVA with repeated measures assessed time, group and interaction effects for all risk factors. There were significant increases in hamstring eccentric peak torque at 60°·s-1 (+8% - 9.9%), the torque produced at 20° (+15%) and 10° (+21% - 31%), as well as a rightward shift in angle of peak torque towards knee extension (-27% - -36%) in both groups (P<0.05). We also observed a significant increase (+24.5%) in hamstring eccentric peak torque at 180°·s-1 in the strength group only and significant improvements (+29.4%) in the rate of torque development of the dominant leg at 60°·s-1 in the sprint group only (P<0.05). No significant effect was noted on sprint performance or sprint mechanics (P>0.05). These findings suggest that both training programs can be effective to mitigate the risk of HSI, but through different mechanisms.

Comparison of Complex and Simple Anthropometrics in the Descriptive Anthropometric Assessment of Male Cyclists

Introduction: Compare the importance of complex (areas and volumes) and simple (lengths and girths) surface anthropometrics in the descriptive anthropometric assessment of the lower body of male cyclists from different disciplines. Method: Using a 3dMDBody5 3D surface imaging system and bespoke software (KinAnthroScan), anthropometrics of the lower body of 23 male non-cyclists and 57 elite male cyclists from different cycling disciplines: sprint (track and road (hill)), endurance (road, &gt; 50 miles), time trial (road, &lt; 50 miles) and mountain bike (cross-country and enduro) were collected. Results: Several anthropometrics differed between cycling groups and when compared to the non-cyclists group; the sprint group demonstrated the largest magnitude of difference with other cycling disciplines and the non-cyclists group, whereas the time trial and mountain bike groups demonstrated the least. Complex anthropometrics were able to distinguish between groups as effectively as simple anthropometrics, and in some cases, were able to distinguish differences that were unidentifiable through simple anthropometrics alone. Conclusions: Researchers, anthropometrists and practitioners should consider the collection and use of complex anthropometrics to improve the understanding of anthropometric differences within descriptive anthropometry, alongside adopting caution when researching groups of cyclists from different disciplines due to their differing anthropometric profiles - categorising them by discipline when possible.

Comparison of Hollow Sprint and Interval Training in Increasing Speed of 100 M Sprint Test

Hollow Sprint Training (accelerated sprint) starts with a slow running motion. Interval training consists of repetitions of a maximum intensity exercise. Detailed data on these two exercises for which one is more effective in increasing the 100 m run is very limited. This study aims to determine the difference in the effect of hollow sprints and interval training in increasing the running speed of 100 meters. Method: A total of 20 samples of 100-meter sprint event athletes participated in this study. The method used was an experiment with a Comparative Design model. The data collection technique used in this study was a test instrument. They were divided into two groups which designed as hollow sprint group (A) and interval training group (B). This study used comparative experimental method where athletes in each group were given two different treatments and a 100meter speed test before and after the treatment. Results: 1) The p-value of the hollow sprint group or group A (0.004) is smaller than 0.05, which can be concluded that group A had a significant increase. 2) The p-value of the interval group or group B (0.006) is smaller than 0.05, which can be concluded that group B had a significant increase. 3) There is a significant difference between hollow sprint and interval training on increasing 100-meter running speed, the p-value (0.035) is smaller than 0.05. Conclusions: Interval training is more effective than hollow sprint training in increasing athletes' 100 meters running speed.

The Effects of Sprint vs. Resisted Sled-Based Training; an 8-Week in-Season Randomized Control Intervention in Elite Rugby League Players.

The aim of the current study was to examine the efficacy of resisted sled-based training compared to traditional unresisted sprint training in terms of mediating improvements in speed, agility, and power during an eight-week period of in-season training in elite rugby league players. Participants were randomly separated into either resisted sled or traditional sprint-based training groups and they completed an eight-week in-season training block with training prescribed based on the group to which they were assigned. Measures of 5 m, 10 m, and 20 m sprint times in addition to countermovement jump height and 505-agility test time were measured at baseline, four-weeks and eight-weeks. For sprint-based outcomes, although both groups improved significantly, there were no statistical differences between the two training methods. However, at the eight-week time point there were significant improvements in 505-agility test (sprint group: baseline = 2.45 and eight-weeks = 2.42 s/sled group: baseline = 2.43 and eight-weeks = 2.37 s) and countermovement jump (sprint group: baseline = 39.18 and eight-weeks = 39.49 cm/sled group: baseline = 40.43 and eight-weeks = 43.07 cm) performance in the sled training group. Therefore, the findings from this investigation may be important to strength and conditioning coaches working in an elite rugby league in that resisted sled training may represent a more effective method of sprint training prescription.

Aging Athlete's Heart: An Echocardiographic Evaluation of Competitive Sprint- versus Endurance-Trained Master Athletes

Sports training triggers exercise-induced cardiac remodeling (EICR). Sprint- and endurance-trained master athletes are exposed to different hemodynamic stimuli accompanied by aging. The aim of this study was to compare EICR types in light of the Morganroth hypothesis, frequency of abnormalities, and relationships between cardiac traits and age. In this observational cross-sectional study, echocardiographic examinations were conducted in 143 sprint-trained (age range, 36-83years) and 114 endurance-trained (age range, 38-85years) competitive master athletes. Structural and functional characteristics were compared with population reference values, and EICR types were identified. Athletic groups were compared using t tests and χ2 tests. Relationships with age were assessed using linear regression. In the sprint group, 51.0% of athletes had normal cardiac geometry (nonhypertrophic heart), 4.2% had eccentric hypertrophy, 36.4% had concentric remodeling, and 8.4% had concentric hypertrophy. In their endurance-trained peers, these proportions were 22.8%, 16.7%, 36.8%, and 23.7%, respectively. Many athletes in both groups had structural abnormalities, as assessed using population norms (up to ~81% for septal thickness) but their resting cardiac function was normal. The relationships of structural and functional cardiac characteristics with age were mostly weak to moderate and did not differ between training modalities. Even though many endurance- and sprint-oriented master athletes exceed population norms for cardiac structure, they do not go beyond the "gray zone" and preserve normal cardiac function. Therefore, physiologic adaptations, rather than pathologic abnormalities, are expected in aging but still active athletes. Inconsistent with the Morganroth hypothesis, EICR is shifted toward normal geometry in sprinters and towardconcentric remodeling and hypertrophy in endurance runners. A better understanding of the mechanisms behind cardiac remodeling during aging is needed to adequately predict EICR types in master athletes.

Applicability of Maximal Ergometer Testing and Sprint Performance in Adolescent Endurance and Sprint Trained Swimmers.

Sprint swimming is a short duration, high intensity sport requiring a relatively greater contribution of energy from anaerobic metabolism. Understanding energy system utilization for the classification of a competitive swimmer (sprint or distance) may be useful for both training prescription and event specialization. The relationship between anaerobic swim ergometer testing and adolescent sprint swimming performance has not been investigated. The purpose of this study was to compare the performance and physiological responses during a maximal all-out ergometer test as well as the maximal anaerobic lactate test in a group of sprint vs. middle-distance specialized swimmers. Sixteen (n = 16) competitive swimmers (mean ± standard deviation (SD), age 16.8 ± 0.7 year; body mass 67.3 ± 9.8 kg) were categorized into two gender matched groups: sprint (n = 8) and middle-distance (n = 8). Each athlete performed (1) a 45 s swim ergometer maximal test to determine peak and mean power output (Watts (W)), (2) a MANLT test to determine peak and average velocity as well as the post-exercise lactate response, and (3) a 50 m swim time trial. The sprint group showed a higher mean (p = 0.026) and peak (p = 0.031) velocity during the MANLT. In addition, blood lactate concentration was significantly (p < 0.01) higher in the sprint vs. middle-distance trained group at 3 and 12 min after completion of the MANLT (3-min post 11.29 ± 2.32 vs. 9.55 ± 3.48 mmol/L; 12-min post 8.23 ± 2.28 vs. 7.05 ± 2.47 mmol/L). The power output during the 45 s all-out swimming ergometer test was higher in the sprint trained group. The results of this study demonstrate the anaerobic contribution to sprint swimming measured during an all-out dryland ergometer test.

Effects of Sprint And Plyometric Training on Speed, Jumping And Anaerobic Strenght of Hearing Impaired Male Sportsmen

The study aims to determine the effect of a 8 week sprint and pliometric training out regularly on speed, jump and anaerobic power parameters among hearing impaired male athletes at the age of 18-21. The measurement and tests of the study was carried out in 2018 and the article was written in 2019 in Samsun. 45 male volunteers with hearing impairment participated in this study. 15 of whom are sprint training (experimental) group aged 19.6±1,18; 15 of whom are pliometrik training (experimental) group aged 19.33±1,12 and 15 of whom are control group aged 19.87±1,19. The experiment groups was made to take sprint and pliometric training practices for 8 weeks, the content of which had been determined before hand while the participants attended their trainings in their local teams. Two assessments were carried out in specified parameters for three groups at the beginning and end of the study. In statistical analysis, the significance level was taken as α=0,05. One way analysis of variance was used to determine the differences between the groups. When the differences were found, Tukey test was used. Paired sample t-test for within group analysis. There are not any statistically difference in parameters of age, weight and training age of the participants (p&amp;gt;0.05). There is statistically significant difference in height parameter (p&amp;lt;0.05). 8 weeks of training, at the end of the results of participants data, there are significant differences among body weight, verticalle and horizontal jumping, 20 meters and 30 meters sprint (p&amp;lt;0,01); anaerobic power, sprint group (p&amp;lt;0.05), pliometric group (p&amp;lt;0,01) positive increase. There is significant difference found in anaerobic strenght in control group (p&amp;lt;0,05). In conclusion, the results of the present study showed that both sprint and plyometric training for 8 weeks improve the sprint, jump and anaerobic power performance.

Short-Term Effects of “Composite” Training on Strength, Jump, and Sprint Performance in Hurling Players

Byrne, PJ, Moody, JA, Cooper, S-M, Farrell, E, and Kinsella, S. Short-term effects of "composite training" on strength, jump, and sprint performance in hurling players. J Strength Cond Res 36(8): 2253-2261, 2022-The purpose of this study was to compare the short-term effects of "composite" training to sprint training on strength, jump, and sprint acceleration performance in hurling players. A randomized counterbalanced group design with baseline test, pretest and post-test measures was used. Twenty-five hurling players volunteered to participate and 21 completed the study. Subjects were divided into a "composite" (COMP group, n = 10) or a sprint training (SPRINT group, n = 11) group. Both groups trained twice per week for 7 weeks with the SPRINT group performing 6 repetitions of 20 m sprints and the COMP group completing 6 repetitions (1 repetition = 3 bounce drop jumps [BDJs] with a 20 m sprint after 15 seconds recovery). Significant differences existed pretraining to post-training for the COMP group for BDJ contact time (-7.25%; p = 0.05) and countermovement jump (CMJ) variables (height: 7.43%, p = 0.006; force: 5.24%, p = 0.05; power: 15.11%, p = 0.001). No significant differences were found between groups at baseline and for group by time interactions. Significant improvements were observed pretraining to post-training in both groups for the following: absolute 3 repetition maximum (3RM) back squat strength (12.73-17.62%, p = 0.01), 5 m (5.74-9.49%, p = 0.006-0.04), 10 m (4.27-5.59%, p = 0.007-0.02), and 20 m (3.35-3.98%, p = 0.003-0.01). In conclusion, "composite" training is effective in enhancing fast stretch-shortening cycle efficiency inducing CMJ force and power augmentation. However, "composite" and sprint training are effective training approaches for enhancing maximal strength and sprint performance in a time efficient manner in hurling players.

Effects of Plyometric and Repeated Sprint Training on Physical Performance.

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.

Sprint versus isolated eccentric training: Comparative effects on hamstring architecture and performance in soccer players.

AimsThe purpose of this study was to compare the effects of hamstring eccentric (NHE) strength training versus sprint training programmed as complements to regular soccer practice, on sprint performance and its mechanical underpinnings, as well as biceps femoris long head (BFlh) architecture.MethodsIn this prospective interventional control study, sprint performance, sprint mechanics and BFlh architecture variables were compared before versus after six weeks of training during the first six preseason weeks, and between three different random match-pair groups of soccer players: “Soccer group” (n = 10), “Nordic group” (n = 12) and “Sprint group” (n = 10).ResultsFor sprint performance and mechanics, small to large pre-post improvements were reported in “Sprint group” (except maximal running velocity), whereas only trivial to small negative changes were reported in “Soccer group” and “Nordic group”. For BFlh architecture variables, “Sprint” group showed moderate increase in fascicle length compared to smaller augment for the “Nordic” group with trivial changes for “Soccer group”. Only “Nordic” group presented small increases at pennation angle.ConclusionsThe results suggest that sprint training was superior to NHE in order to increase BFlh fascicle length although only the sprint training was able to both provide a preventive stimulus (increase fascicle length) and at the same time improve both sprint performance and mechanics. Further studies with advanced imaging techniques are needed to confirm the validity of the findings.

Mobilization of Cardiovascular Function at Onset of Dosed Aerobic and All-Out Anaerobic Workouts

The objective of this study was to compare the peculiarities in the mobilization of cardiovascular function at the onsetof an exercise test in dependence on age and the type of adaptation to physical loads. The study’s participants were boysof 11, 12, 13 and 14 years old and adults, i. e. 17 voluntary students who were not engaged in sports training and well-trained athletes (all participants were members of various national teams), i. e. 23 athletes in the endurance group, 19 —in the sprint group and 21 — in the combative sports group (box, judo and wrestling). The subjects underwent:1) Roufier’s test (30 squats per 45 seconds); 2) a 30-second duration maximal vertical jump test. A computerizedelectrocardiogram (ECG) system “Kaunas-Load” was employed for the 12-lead ECG recording and analysis during theperformance of workloads. A computerized program allowed to measure the ratio of JT and RR intervals (JT / RR) andthe velocity of adaptation of cardiovascular system to exercise, i.e. the index of velocity of adaptation (V Ad ), by calculationthe difference between the relative changes of JT and RR intervals as a difference: V Ad . = (Jt i / JT 0 ) 100% – (Rr i / RR 0 ) 100%. The results obtained during the study allowed to conclude that faster adaptation at the onset of the exerciseis rather characteristic for younger persons but the type of the exercise performed during the long term training processplays a significant role in the developing and improving the velocity of adaptation of cardiovascular system. A fasteradaptation at the onset of the exercise is a more characteristic feature for the trained athletes in sprint events andcombative sports than the representatives of the endurance group or non-athletes. One of the effects of long termadaptation to exercise is a smaller mobilization of cardiovascular system at the onset of the dosed aerobic and all-outanaerobic exercise and the endurance exercise has the most influence on it.Keywords: cardiovascular system, adaptation, exercise test.

PO-120 Research on the fluctuation of Reticulocyte during different altitude training patterns in swimming athletes

Objective To explore the fluctuation of reticulocyte during different altitude training in swimming athletes and their difference between altitude training focused on special aerobic capacity and altitude training focused on high load and sprint, to provide the theory basis for further analyze the altitude training improve the physiological function and athletic performance.&#x0D; Methods Twenty female swimming athletes participated in altitude training for four weeks, which could be divided into two patterns, special aerobic capacity group(G1, n=9) and intensity and sprint group(G2, n=11). Fasting venous blood samples were drawn for each week were determined using Beckman Coulter LH780 automated hematology analyzer, including Reticulocyte related parameters such as Reticulocyte percentage (Ret%), Reticulocyte count (Ret#) and immature Reticulocyte fraction (IRF) and also erythrocyte related parameters.&#x0D; Results (1) In G1, Ret%, Ret# and MRV showed continuous decline and represented minimum level in 4th week. While IRF increased during 2nd and 3rd, and then decreased in 4th week. (2) In G2, Ret%, Ret# and MRV were relatively steady during 1st and 2nd week. Ret% and Ret# gave an increased in 3rd week, and then decreased in 4th week, while MRV decreased in 3rd week and increased in 4th week. IRF significantly decreased in latter period compared to earlier period. (3) There were no significant changes for RBC, HCT and HGB in both G1 and G2. MCV, MCH, MCHC and RDW showed improved in later stages compared to their in earlier stages for all in G1, while MCV increased and then decreased, MCH and MCHC continued decline, and RDW kept at sustaining higher levels in G2.&#x0D; Conclusions (1) Reticulocytes were not in accordance with the trend of erythrocyte during different altitude training. Compared to erythrocyte, the behavior of Reticulocyte could reflect erythropoiesis, and IRF could more sensitively detect the change of bone marrow stimulation in particular.&#x0D; (2) The variability of Reticulocytes during altitude training was influenced by hypoxia, training and especially their interactive effects. In aspect of training type, it was crucial for considering the fluctuation of training load and athletes’ adaptation during different patterns. &#x0D;

Autonomic modulations of heart rate variability are associated with sports injury incidence in sprint swimmers

ABSTRACTObjectives: Young athletes’ participation in competitive sports is becoming increasingly common, and this increased involvement raises concerns about the occurrence of overtraining and sports injuries. Since these issues are poorly understood, this study analyzed heart rate variability, stress/recovery relationship, and sports injury incidence during a training macrocycle of young sprint and endurance swimmers.Methods: Thirty teenage swimmers (aged 12 to 17 years) were divided into two groups as follows: Sprint (n = 17) and Endurance (n = 13). Subjects were evaluated over 20 weeks, based on the following three schedules: general, specific, and competitive. In addition to heart rate variability and sports injury incidence, the Recovery-Stress-Questionnaire of Athletes was used to analyse stress/recovery states in athletes. All procedures were developed at the initial moment and at the end of each periodization step.Results: The Sprint group presented a reduced standard deviation of normal-normal beats (73.0 ± 6.6 vs. 54.1 ± 3.5 ms; p < 0.05) and root mean square of the successive differences (55.3 ± 6.2 vs. 42.0 ± 3.7 ms; p < 0.01) from the period of general preparation until the time of competition. Recovery-stress monitoring was affected only by the swimming training periodization (p < 0.05). During the general period, differences between recovery and stress scales were correlated directly with the root mean square of the successive differences (r = 0.576; p = 0.001), the standard deviation of instantaneous variability beat-to-beat (r = 0.521; p = 0.003) and the triangular index (r = 0.476; p = 0.008). Differences between general recovery and stress scales were inversely correlated with geometric indexes after the specific training period. Moreover, the Sprint group showed a higher incidence of sports injury than the Endurance group (0.0214 ± 0.0068 vs. 0.0136 ± 0.0050 cases/1000 hours).Conclusion: Sprint training was associated with progressive activation of the sympathetic nervous system as well as a higher incidence of sports injury in comparison to endurance swimming during a training macrocycle.

Sprint interval training on the vertical treadmill improves aerobic and anaerobic running performance.

The vertical treadmill (VertiRun) is an unresearched mode of exercise where users engage in a “running-like” action whilst body weight is supported by a recumbent bench and overhanging resistance cables are tethered to the user’s ankles. The purpose of this study was to determine the effects of training on a VertiRun and any cross-training effect on running performance. Thirty active males (age, 22±4 years; stature, 1.79±0.08 m; body mass, 78.5±12.6 kg) volunteered for this study. Participants’ aerobic and anaerobic running performance were determined by incremental maximum rate of oxygen consumption (VO2max) treadmill test and a maximum anaerobic running test (MART), respectively. Participants were matched and then randomly assigned to either a VertiRun group, 20-m shuttle sprint group or control group. The intervention consisted of 4–6, 30-sec all-out efforts with 4-min recovery between bouts, 3 days a week for 6 weeks. The pre- and postintervention VO2max and MART were analysed using a mixed repeated measures analysis of variance. MART increased by 4.5% in the VertiRun group (P=0.006) and 4% in the sprint group (P<0.001). VO2max increased by 6.2% in the VertiRun group (P=0.009) and 5.5% in the sprint group (P=0.020). The MART and VO2max of the control group were unchanged (P=0.910 and P=0.915, respectively). These data suggest that the VertiRun could be an effective cross-training mode for running and could supplement training programmes. Also, as VertiRun is a low-impact exercise it might be useful in the physical preparation of athletes returning to sport following lower limb injury.

Modeling in Football Training: The Effect of Two Methods of Training Based on Small Sided Games and Repeated Sprints on Mood and Physical Performance among Footballers

The aim of the study was to compare the effect of additional practice/training of small-sided games (SSG) or repeated sprints (RS) on mood state, and physical performance in professional soccer players. Twenty four professional soccer players took part in this study (age: 17 ± 0.19 years). Participants were divided into two groups: small-sided gamed group (GSSG) performed 3 bouts of SSG (3 versus 3 players on 25 × 30 m pitch size) and repeated sprint group (GRS) performed 3 bouts of RS (6 × 40 + 40-m sprint with 20s of passive recovery in-between). Both groups were trained over a period of seven weeks (2 sessions/weeks) with the usual practice. The profile of mood state (POMS), the YOYO intermittent recovery test (YOYOTRT), sprint 10-m and five-jump test were conducted before and after training program. After 7 weeks of training, no changes in mood were determined, but run distance improved in both groups. Sprint time and leg strength improved in the RSG only. Coaches and physical trainers could choose between these two training modalities according to the objective of their training, keeping in mind the brief and intense actions advantages of the RS shown in the present study.

Discriminant musculo-skeletal leg characteristics between sprint and endurance elite Caucasian runners.

Excellence in either sprinting or endurance running requires specific musculo-skeletal characteristics of the legs. This study aims to investigate the morphology of the leg of sprinters and endurance runners of Caucasian ethnicity. Eight male sprinters and 11 male endurance runners volunteered to participate in this cross-sectional study. They underwent magnetic resonance imaging and after data collection, digital reconstruction was done to calculate muscle volumes and bone lengths. Sprinters have a higher total upper leg volume compared to endurance runners (7340 vs 6265cm3 ). Specifically, the rectus femoris, vastus lateralis, and hamstrings showed significantly higher muscle volumes in the sprint group. For the lower leg, only a higher muscle volume was found in the gastrocnemius lateralis for the sprinters. No differences were found in muscle volume distribution, center of mass in the different muscles, or relative bone lengths. There was a significant positive correlation between ratio hamstrings/quadriceps volume and best running performance in the sprint group. Sprinters and endurance runners of Caucasian ethnicity showed the greatest distinctions in muscle volumes, rather than in muscle distributions or skeletal measures. Sprinters show higher volumes in mainly the proximal and lateral leg muscles than endurance runners.

Effects of Resisted Sprint Training on Sprint Performance in High School Baseball Players

Resisted sprint training (RST) affects sprint speed in the acceleration phase, but there is no research regarding this for in adolescents. This study investigated the effects of RST on sprint speed and ground reaction force (GRF) in high school baseball players. Subjects were assigned to the resisted sprint group (RSG, n=10, loading 20% body mass), or the normal sprint group (NSG, n=9, without loading) and trained three days per week for eight weeks. Sprint speed [0-5, 5-10, 10-15, 15-20 and 0-20 meters (m)] and GRF [peak propulsive/resultant force, (PFpro/ PFres); impulse, (I); and ratio of force applied onto the ground (RF)] measured at the right and left foot at the start, the first step of the left foot (L1st), 5 m and 10m were assessed before and after training. In the RSG, a significant interaction was found for sprint speed at 0-5 m (p=0.028) and increased after training (p<0.0001). The 15-20 m sprint speed increased significantly in the NSG after training (p=0.022). The 0-20 m sprint speed increased significantly in both groups after training (RSG, p=0.001; NSG, p=0.041). Significant interactions were found for PFpro (p=0.015) and RF (p=0.0002) at the L1st in the RSG. PFpro (p=0.005), PFres (p=0.038) and RF (p=0.0002) at L1st increased significantly in the RSG. RST increased sprint speed in the early part of the acceleration phase by improving force production but prevented the improvement of sprint speed over 15 m. Combining RST and sprint training without loading improved sprint speed in the acceleration phase.