Race Velocity Research Articles

The success of critical velocity protocol on predicting 10000 meters running performance

Background and Study Aim. The study aims to evaluate which of the critical velocity (CV) estimates of the three widely used models and the best-fit model successfully predict the running performance of 10000 meters. Materials and Methods. The group of participants in this study consisted of 11 British endurance athletes. The CV estimations were obtained from the models with the athletes' running velocity and exhaustion times of 1500, 3000, and 5000 meters (m). The information was taken from a website where the results of the British athletes are recorded. In terms of selecting endurance athletes, the data of the athletes who ran 1500 m, 3000 m, 5000 m, and 10000 m in the same two years were included in this study. By fitting the data into mathematical models, the CV estimates of the three mathematical models and the individual best-fit model were compared with the 10000 m running velocity. The CV estimates were obtained by fitting the relevant data on the running velocity, exhaustion time, and running distance of the three running distances of athletes to each of the three mathematical models. Results. 10000 m running velocity and times of the athletes corresponded to 19.65 ± 1.26 km-1 and 30.4 ± 1.94 minutes, respectively. The CV values obtained from the three mathematical models and 10000 m running velocity were similar (p > 0.05). Although the lowest total standard error levels were obtained with the best individual fit method, the 10000 m running velocity was overestimated (p < 0.05). Conclusions. Three mathematical models predicted 10000 meters of race velocity when an exhaustion interval between 2-15 minutes was used. Even though the mathematically most valid CV value was obtained with the best individual fit method, it overestimated the 10000 m running velocity. When comparing the values of CV and the velocity of running 10,000 meters, our study suggests using the linear 1/velocity model. This is because the linear 1/velocity model has the smallest effect size, and there is no statistically significant difference in the total standard error level between the linear 1/velocity model and the best-fit model.

Prediction of 2000-m on-water rowing performance with measures derived from instrumented boats.

Rowing instrumentation systems provide measures of stroke power, stroke rate, and boat velocity during rowing races, but how well these measures predict race performance has not been reported previously. Data were collected per stroke from 45 2000-m races using Peach PowerLine and OptimEye S5 GPS units. The boat classes assessed were nine male singles, eight female singles, three male pairs, and six female pairs. Random effects and residuals from general linear mixed modeling of stroke velocity adjusted for stroke power, stroke rate, and mean headwind provided measures interpreted as technical efficiency, race conditions, and stroke-velocity variability. These measures, along with mean race power, mean stroke rate, and mean headwind were then included in multiple linear regressions to predict race velocity from official race times. Effects were assessed for 2 SD changes in predictors and interpreted using interval hypothesis tests. Effects of mean race power, mean stroke rate, and mean headwind on race velocity ranged from small to extremely large and were mostly decisively substantial. Effects of technical efficiency and race conditions ranged from trivial to extremely large but were generally unclear, while stroke-velocity variability had trivial-small and mostly unclear effects. Prediction error was small to moderate and decisively substantial. Men's pairs lacked sufficient data for analysis. On-water rowing race performance can be predicted with mean race values of power, stroke rate, and headwind. Estimates from stroke data are potentially useful predictors but require impractical numbers of boats and races to reduce their uncertainty.

Pacing Strategies of 1500 m Freestyle Swimmers in the World Championships According to Their Final Position.

In 1500 m freestyle swimming races, pacing is generally represented by a parabolic or U-shaped curve indicating that swimming velocity is greatest at the start and the last laps of the race while swimmers maintain an even pace through the middle section of the race. However, there is no information to determine if 1500 m race winners select pacing different to other, less successful swimmers within the same competition. Therefore, this investigation aimed to describe the pacing strategies adopted by 1500 m freestyle competitive swimmers in World Championships (long course), from 2003 to 2019 to determine the most effective pacing to obtain victory or a medal. The official overall and split times for 1500 m freestyle races of the Fédération Internationale de Natation (FINA) were obtained from the website of this organization. In total, data of 143 swimming performances (71 male and 72 female) were extracted. With the split times, lap times, and position were calculated across the race. To determine differences in the pacing between best- and worst-ranked finalist, swimmers in each race were divided into four groups based on the final position (1st vs. 2nd vs. 3rd vs. 4–8th). All the lap times of the winners of the race were faster than those of participants classified as 4–8th position for men and women races (p < 0.05). However, there were no differences in lap velocity among the different positions achieved at the end of the race when it was normalized by average race velocity. Additionally, there were no differences in the lap-to-lap variability among swimmers with different positions at the end of the race. In summary, both men and women elite swimmers selected parabolic pacing consisting of a fast start in the first lap, an even pace close to their average race velocity in the mid-section of the race (from 50 to 1400 m), followed by an end spurt in the final lap(s). This pattern was very similar in all finalists irrespective of the final position in the race. Hence, the obtaining of a medal in the World Championships was associated to possessing a faster average race velocity rather than a specific pacing profile through the race.

Bicycling and Tricycling Road Race Performance in International Para-Cycling Events Between 2011 and 2019.

This study described bicycling (C classes) and tricycling (T classes) performance in the International Cycling Federation road race events between 2011 and 2019. A total of 3243 race results from 33 events were analyzed. Race velocity was calculated for each result. Bicycling and tricycling data were separately modeled using a linear mixed-effects model. Bicycling velocity was statistically different between all adjacent men's classes (Cohen d = 0.14-0.73) and between the women's C1 and C2 (d = 1.15) and C3 and C4 (d = 0.48) classes. The absence of statistical differences between some women's bicycling classes may be due to a limited number of observations in these classifications. As expected, velocity was statistically different between men's (d = 1.64) and women's (d = 1.38) T1 and T2 classes. Road race performance was hierarchical within the disciplines of bicycling and tricycling, although not all adjacent women's bicycling classes were statistically different. The existence of a performance hierarchy does not necessarily validate the classification system. The integration of information regarding athlete impairment type and severity, with performance data, would provide greater insight into the validity of the classification system and should be prioritized as an area of future research.

High-fat versus high-carbohydrate diets for optimal higher intensity endurance exercise performance: and the winner is….

High-fat versus high-carbohydrate diets for optimal higher intensity endurance exercise performance: and the winner is….

The Advantage of Supine and Standing Heart Rate Variability Analysis to Assess Training Status and Performance in a Walking Ultramarathon.

Cardiac autonomic modulation of heart rate, assessed by heart rate variability (HRV), is commonly used to monitor training status. HRV is usually measured in athletes after awakening in the morning in the supine position. Whether recording during standing reveals additional information compared to supine remains unclear. We aimed to evaluate the association between short-duration HRV, assessed both in the supine and standing position, and a low-intensity long-duration performance (walking ultramarathon), as well as training experience. Twenty-five competitors in a 100 km walking ultramarathon underwent pre-race supine (12 min) and standing (6 min) HR recordings, whereas performance and subjective training experience were assessed post-race. There were no significant differences in both supine and standing HRV between finishers (n = 14) and non-finishers (n = 11, mean distance 67 km). In finishers, a slower race velocity was significantly correlated with a higher decrease in parasympathetic drive during position change [larger decrease in High Frequency power normalized units (HFnu: r = −0.7, p = 0.01) and higher increase in the detrended fluctuation analysis alpha 1 index (DFA1: r = 0.6, p = 0.04)]. Highly trained athletes accounted for higher HFnu during standing compared to poorly trained competitors (+11.5, p = 0.01). Similarly, greater training volume (total km/week) would predict higher HFnu during standing (r = 0.5, p = 0.01). HRV assessment in both supine and standing position may provide additional information on the dynamic adaptability of cardiac autonomic modulation to physiologic challenges and therefore be more valuable for performance prediction than a simple assessment of supine HRV. Self-reported training experience may reliably associate with parasympathetic drive, therefore indirectly predicting long-term aerobic performance in ultramarathon walking races.

Relationships between a Load-velocity Profile and Sprint Performance in Butterfly Swimming.

The purpose of this study was to establish the relationships between 50 m sprint swimming performance and variables acquired from a swimming load-velocity profile established by semi-tethered butterfly swimming. Twelve male elite swimmers participated in the present study and performed 50 m sprint and semi-tethered butterfly swimming with different loads. The mean velocity among all upper-limb cycles was obtained from the 50 m swimming (race velocity), and maximum load and velocity were predicted from the load-velocity profile established by the semi-tethered swimming test. There was a very large correlation (r=0.885, p<0.01) and a high intra-class correlation (0.844, p<0.001) between the race velocity and the predicted maximum velocity. Significant correlations were also observed between the predicted maximum load and the 50 m time as well as the race velocity (r=- 0.624 and 0.556, respectively, both p<0.05), which imply that an ability to achieve a large tethered swimming force is associated with 50 m butterfly performance. These results indicate that the load-velocity profile is a useful tool for predicting and assessing sprint butterfly swimming performance.

Analysis of Aerobic Power and Swing Characteristics in Young Male Race Walkers

Economical walking is defined by the steady state of oxygen consumption with top speed and technique in competition is one of the most important factors to achieve higher performance for Pedestrians. The technique of race walking which is defined by World Athletics race walking competitions rules 230.54.2 not a naturally obtained human skill as normal walking and running of childhood. The purpose of the study was to analyze the association and relation of race velocity with aerobic capacity and kinematic properties. Top 10 race walkers of 10000m race walk discipline (Men- U 20), from 33^rd National Junior Athletic Championships, Nov, 2017 held at Acharya Nagarjuna University, Vijaywada, A. P. India were digitized as the subject. For kinematic analysis, athletes were recorded as they passed through halfway 4.55 KM at back straight on the 400 m track by using two standard digital HD camcorders (Nikon B700, 60Hz) mounted on rigid tripods 90° angle 4 m away from the track inside & outside where reference volume was 5 m long and 1.5 m high. Whereas to measure Vo₂ Max athletes’ performance were taken as they passed through 1.5 miles or 2414.02 m on the track. The video data were analyzed by using motion analysis software (KINOVEA). Descriptive statistics and Pearson Product Moment Correlation coefficient (<i>p</i><0.05) were employed for statistical calculation. The tabulation of data was done by using the IBM SPSS software. The result of the study showed that the correlation between race performance and VO₂ max was quite high, r (8df) = 0.726. A Strong relationship was found between step length and RW performance, i.e. r (8df) = 0.689. Whereas variables like, flight time, linearity, maximum knee and foot height of swing leg were positively correlated with the walking performance. A high degree positive association was located in the torso and pelvic displacement r = 0.768 & 0.804 respectively. In toe off phase “r” value of knee angle with performance was 0.742 that showed a high degree coefficient of correlation. Whereas at heel contact and mid stance phase a low degree negative correlation found (r = -0.489& -0.406). Most of the calculated “r” values were significant as the critical value of 8 df at 0.05 level is 0.631. Due to the direct association of race walking velocity (Mean = 3.427 m/s & SD = 0.235) with VO₂ max, step length, knee angle, torso & pelvic displacement may be this type of result found indifferent phases. Race walking performance was positively associated with the race walking economy (kinematic and physiologic variables), which implies that the fastest race walkers were more economical than the lesser performers. In relation to RW technique and forward propulsion, displacement of torso and pelvic region observed a significant role.

Influence of Adventure Race Disciplines on the Overall Performance during 35 to 50-km Races

Abstract Aims: This study aims to analyze the influence of adventure race disciplines on the overall performance during 35 to 50-km competitions. Methods: Twenty-four athletes from twelve teams were studied during the second (Jacarei-SP, Brazil, 44.5-km) and fourth (Passa Quatro-MG, Brazil, 37.1-km) races of the 2015 Haka Race Series, which comprised Brazilian Adventure Race Ranking. We analysed the relationship between disciplines velocities and overall race velocity of the teams during each competition. Results: We observed the race velocity of the teams during second race was significantly (P < 0.05) correlated with the first (R=0.80) and last (R=0.65) split velocities of trekking, and with the last split velocity of mountain biking (R=0.73). On the other hand, the race velocity of teams during fourth race was significantly (P < 0.05) correlated with the split velocity performed during the course of water trekking with trekking (R=0.96). Conclusion: Greater performance of the athletes in the disciplines of mountain biking, trekking and water trekking is related to their overall performance during 35-50 km ARs. In addition, the influence of adventure race disciplines is specific to the overall performance during different competitions.

Race Strategies of Open Water Swimmers in the 5-km, 10-km, and 25-km Races of the 2017 FINA World Swimming Championships.

Despite literature on the pacing strategies of endurance sports, there is an existing lack of knowledge about the swimmers’ tactical decisions in the open water races. The aims of the present research were (1) to compare the pacing profiles and tactical strategies of successful elite open water swimmers (men and women) in the 5-km, 10-km, and 25-km races and (2) to relate these pacing strategies to the end race results. Intermediate split times, positions and gaps with leaders of the first ten swimmers classified in the 2017 FINA World Swimming Championships races were collected from the public domain and were related to the finishing positions. Overall swimming velocities of the 5-km races were faster than the 10-km (δ 0.03 ± 0.03 m/s) and the 25-km (δ 0.14 ± 0.01 m/s) events with male swimmers achieving relatively faster mean velocities than females in the 5-km (δ 0.12 ± 0.01 m/s) compared to the 25-km (δ 0.08 ± 0.01 m/s) events. Medallist swimmers achieved moderate faster overall velocities than finalists in the 25-km races (0.01 ± 0.01 m/s) only. Inter-level differences were detected in selected splits for each race distance. Pacing profiles presented lap to lap velocity improvements in the 5-km and men’s 10-km races (from +0.02 ± 0.00 to +0.11 ± 0.01 m/s) but also mid-race decreases in the women’s 10-km and on the 25-km races. Successful swimmers were located in the leading positions of the 5-km races but at mid-group in the first part of the 10-km and 25-km races, with time gaps with leaders of 15–20 s. Faster lap swimming velocities, mid-race leading positions and shorter time-gaps were only related to the finishing positions in the last lap of the 10-km and in the three last laps of the 25-km events, but also in the first lap of the women’s 5-km race. Despite different mid-race positioning, successful open water swimmers typically presented negative pacing profiles, a consistent control of mid-race gaps with leaders (15–20 s maximum) and great spurts (4–6% faster than mean race velocities) at the end of races. Coaches and swimmers should be aware of the different race dynamics depending to the event distance in order to select optimal race strategies.

Macro-Kinematic Differences Between Sprint and Distance Cross-Country Skiing Competitions Using the Classical Technique.

We compare the macro-kinematics of six elite female cross-country skiers competing in 1.1-km Sprint and 10.5-km Distance classical technique events on consecutive days under similar weather and track conditions. The relative use of double pole (DP), kick-double pole (KDP), diagonal stride (DS), tucking (Tuck) and turning (Turn) sub-techniques, plus each technique’s respective velocities, cycle lengths and cycle rates were monitored using a single micro-sensor unit worn by each skier during the Sprint qualification, semi-final and finals, and multiple laps of the Distance race. Over a 1.0-km section of track common to both Sprint and Distance events, the mean race velocity, cyclical sub-technique velocities, and cycle rates were higher during the Sprint race, while Tuck and Turn velocities were similar. Velocities with KDP and DS on the common terrain were higher in the Sprint (KDP +12%, DS +23%) due to faster cycle rates (KDP +8%, DS +11%) and longer cycle lengths (KDP +5%, DS +10%), while the DP velocity was higher (+8%) with faster cycle rate (+16%) despite a shorter cycle length (-9%). During the Sprint the percentage of total distance covered using DP was greater (+15%), with less use of Tuck (-19%). Across all events and rounds, DP was the most used sub-technique in terms of distance, followed by Tuck, DS, Turn and KDP. KDP was employed relatively little, and during the Sprint by only half the participants. Tuck was the fastest sub-technique followed by Turn, DP, KDP, and DS. These findings reveal differences in the macro-kinematic characteristics and strategies utilized during Sprint and Distance events, confirm the use of higher cycle rates in the Sprint, and increase our understanding of the performance demands of cross-country skiing competition.

Bend sprinting performance: new insights into the effect of running lane

Athletes in inner lanes may be disadvantaged during athletic sprint races containing a bend portion because of the tightness of the bend. We empirically investigated the veracity of modelled estimates of this disadvantage and the effect of running lane on selected kinematic variables. Three-dimensional video analysis was conducted on nine male athletes in lanes 8, 5 and 2 of the bend of an outdoor track (radii: 45.10, 41.41 and 37.72 m, respectively). There was over 2% (p < 0.05) reduction in mean race velocity from lane 8 (left step 9.56 ± 0.43 m/s, right step: 9.49 ± 0.41 m/s) to lane 5 (left step: 9.36 ± 0.51 m/s, right step: 9.30 ± 0.51 m/s), with only slight further reductions from lane 5 to lane 2 (left step: 9.34 ± 0.61 m/s, right step: 9.30 ± 0.63 m/s). Race velocity decreased mainly because of reductions in step frequency as radius decreased. These unique data demonstrate the extent of the disadvantage of inner lane allocation during competition may be greater than previously suspected. Variations in race velocity changes might indicate some athletes are better able to accommodate running at tighter radii than others, which should have implications for athletes’ training.

The Effect Of Acute Body Mass Reduction On Metabolism And Endurance Running Performance

Reduced body mass and/or relative fat mass is expected to improve endurance running performance, by lowering energy cost of running and allowing the runner to maintain higher mean race velocity using identical %VO2max. The majority of studies during the last 40 years have been centered mainly on the effect of adding external load on energy cost of walking and running. PURPOSE: The purpose of this study was to examine the effect 5 and 10% reduction of inactive body mass on metabolic responses and 3 km running performance. METHODS: Eleven trained (8 male, 3 female) club level runners (mean ± sd body mass, height, %fat, peakVO2 and vVO2max, 65.71 ± 12.07 kg, 174.59 ± 8.32 cm, 12.54 ± 3.55%, 56.30 ± 4.57 ml.kg-1.min-1 and 17.1 ± 1.4 km.h-1 respectively) participated in a series of 4 maximal trials 4–6 days apart. During the first trial, the subjects completed an exhaustive incremental peakVO2 test on the treadmill. On the second visit they completed a 3 km race time trial on the treadmill running with normal body mass (BM). During the last two laboratory visits, the subjects completed two 3 km race trials in random order on the treadmill while body mass (a rope through a system of pulleys lifted the runner with the calculated body weight throughout striding phases while not interfering with running technique) was reduced 5 (5%BM) or 10% (10%BM). Repeated Anova was used for the statistical analysis. RESULTS: Mean (±sd) 3 km performance time was lowered (improved) during 5%BM (663.5 ± 76.05 s) and 10%BM (648.9 ± 74.9 s) trials (p<0.05) compared with BM (684.9 ± 74.8 s). The 5 and 10% reduction in body mass induced a mean 3.1 and 5.2% improvement in 3 km race performance accordingly. Every kg reduction of inactive body mass improved 1.4% running endurance performance. Mean values of the Rate of perceived exertion, heart rate, VO2 ml.min-1, RQ, Blood lactate and Volume of expired air were not different between time trials and peak VO2max test (p>0.05). CONCLUSIONS: The results of the present study showed that the reduction of 5 and 10% of inactive body mass may improve significantly 3 km performance time without noticeable effects on metabolic parameters and are supportive of the notion that one way to maximize further running performance is to reduce inactive body mass.

Allometric scaling of body mass in running economy data: An important consideration in modeling marathon performance

The purpose of this study was to compare metabolic variables during submaximal running as predictors of marathon performance. Running economy (RE) and respiratory exchange ratio (RER) data were gathered during a 30 min incremental treadmill run completed within 2 weeks prior to running a 42.2-km marathon. Paces during the treadmill run progressed every 5 min from 75-100% of 10-km race velocity. Variables at each stage were analyzed as predictors of relative marathon performance (RMP) in competitive (COMP) and recreational (REC) runners. Twenty-nine runners were classified as COMP (n = 12; age 30 ± 8 years) or REC (n =17; age 20 ± 1 year) based on performance in shorter races. RMP was calculated as percent difference from predicted marathon finish time. Two methods of calculating RE were used: unscaled (ml . kg -1. km -1 ) and with allometric scaling of body mass (ml . kg -0.75. km -1 ). The COMP runners were significantly more economical than REC ( p =0.005; p =0.015 with scaling). For the whole population, RE with and without scaling was significantly correlated with RMP. Within groups, RMP was not significantly correlated with RE unless scaling was used: COMP runners at 75% ( p =0.044), 80% ( p =0.040), and REC runners at 85% ( p =0.038). Runners classified as COMP were more economical than REC, but RER was not different. The use of allometric scaling is important when assessing homogeneous groups. In this study, allometrically-scaled RE at 80-85% of 10-km velocity was the best predictor of RMP within groups.

An empirical study of race times in recreational endurance runners.

BackgroundStudies of endurance running have typically involved elite athletes, small sample sizes and measures that require special expertise or equipment.MethodsWe examined factors associated with race performance and explored methods for race time prediction using information routinely available to a recreational runner. An Internet survey was used to collect data from recreational endurance runners (N = 2303). The cohort was split 2:1 into a training set and validation set to create models to predict race time.ResultsSex, age, BMI and race training were associated with mean race velocity for all race distances. The difference in velocity between males and females decreased with increasing distance. Tempo runs were more strongly associated with velocity for shorter distances, while typical weekly training mileage and interval training had similar associations with velocity for all race distances. The commonly used Riegel formula for race time prediction was well-calibrated for races up to a half-marathon, but dramatically underestimated marathon time, giving times at least 10 min too fast for half of runners. We built two models to predict marathon time. The mean squared error for Riegel was 381 compared to 228 (model based on one prior race) and 208 (model based on two prior races).ConclusionsOur findings can be used to inform race training and to provide more accurate race time predictions for better pacing.Electronic supplementary materialThe online version of this article (doi:10.1186/s13102-016-0052-y) contains supplementary material, which is available to authorized users.

Competitive Marathon Runners Exhibit Greater Running Economy than Recreational Runners

INTRODUCTION: Running economy (RE) has been identified as a predictor of distance running performance. More experienced runners are generally more economical than novice or recreational runners, requiring less oxygen to cover the same distance. Given the metabolic cost of marathon running, it was hypothesized that competitive runners (COMP) would be more economical than recreational runners (REC), and that RE at sub-maximal paces would be associated with marathon performance (MP) in both groups. PURPOSE: To compare RE in COMP versus REC runners, and to determine whether it is associated with MP in each group. METHODS: Twenty-nine runners (ages 18-47, 15 male and 14 female) completed a time trial or road race (from 2-miles to 10-km), a 30-minute sub-maximal treadmill run progressing through 6 stages of 5-min from 75 to 100% of 10-km race velocity, and a 26.2 mile road marathon. If necessary, velocities for the 30-min run were set by converting race times to a 10-km equivalent. Oxygen use was assessed continuously during the 30-min run via metabolic cart. Projected marathon finish times were determined using published race time equivalency charts. Marathon performance was reported as percent difference from predicted finish time, with a positive value indicating a slower than expected marathon. Twelve runners (30 ± 8 years, 3 female) had projected marathon finish times of 3:10 or faster (2:58 ± 13 min) and were categorized as COMP, with the other nineteen runners (20 ± 1 years, 11 female) categorized as REC (4:18 ± 41 min). RESULTS: Average O2 use over the 30-min run was 194.7 ± 9.8 ml/kg/km for COMP and 211.6 ± 17.3 ml/kg/km for REC (p=0.005). Both groups ran slower than predicted for the marathon. The percent off expected MP for COMP was 1.7 ± 3.2% and for REC was 15.7 ± 5.8% (p≤0.001). For all runners, O2 use was associated with MP (p≤0.001). By group, there was a trend toward an association between RE and MP. The correlations for REC and COMP runners were 0.419 (p=0.094) and 0.386 (p=0.215). CONCLUSIONS: Competitive runners are more economical than recreational runners and run closer to the marathon finish times predicted by shorter races. Within each category, runners with better RE tend to run closer to their predicted times in the marathon. Running economy may be a more important predictor of performance in the marathon than in races of shorter distances.

Physiological Performance Determinants of a 22-km Handbiking Time Trial.

To investigate physiological performance determinants of the partial laps and an overall 22-km handbiking (HB) time trial in athletes with high paraplegia. Seven male HB athletes with spinal cord injury (lesion levels thoracic 2-8) performed a laboratory maximal incremental test under cardiorespiratory-mechanical monitoring including respiratory-exchange ratio (RER), oxygen uptake (VO2), and mechanical power output (PO). Individual first and second ventilatory thresholds (VO 2VT1 and VO 2VT2), VO 2peak, and PO peak were posteriorly identified. Athletes also performed a simulated HB time trial along a 4-lap bike circuit under cardiorespiratory measurement. Overall metabolic cost (C) and %VO 2peak (ratio of VO2 to VO 2peak) were calculated from race data. Race performance was defined as mean race velocity (v). athletes completed the 22-km HB time trial in 45 ± 6 min, at 29.9 ± 3.6 km/h, with %VO 2peak = 0.86 ± 0.10 and RER = 1.07 ± 0.17. VO 2peak (r = .89, P = .01), POpeak (r = .85, P = .02), VO 2VT1 (r = .96, P = .001), VO 2VT2 (r = .92, P = .003), and C (2nd lap, r = .78; 3rd lap, r = .80; and 4th lap, r = .80) were significantly (P < .05) positively correlated with race performance. Within-subjects correlation coefficient revealed a large and significant (r = .68, P < .001) relationship between %VO 2peak and v. VO 2peak, PO peak, ventilatory thresholds, %VO 2peak, and C appeared to be important physiological performance determinants of HB time trial.

The effect of the bend on technique and performance during maximal effort sprinting

This study investigated changes in performance and technique that occur during maximal effort bend sprinting compared with straight-line sprinting under typical outdoor track conditions. Utilising a repeated measures design, three-dimensional video analysis was conducted on seven male sprinters in both conditions (bend radius: 37.72 m). Mean race velocity decreased from 9.86 to 9.39 m/s for the left step (p = 0.008) and from 9.80 to 9.33 m/s for the right step (p = 0.004) on the bend compared with the straight, a 4.7% decrease for both steps. This was mainly due to a 0.11 Hz (p = 0.022) decrease in step frequency for the left step and a 0.10 m (p = 0.005) reduction in race step length for the right step. The left hip was 4.0° (p = 0.049) more adducted at touchdown on the bend than the straight. Furthermore, the bend elicited significant differences between left and right steps in a number of variables including ground contact time, touchdown distance and hip flexion/extension and abduction/adduction angles. The results indicate that the roles of the left and right steps may be functionally different during bend sprinting. This specificity should be considered when designing training programmes.

The 3D CFD study of gliding swimmer on passive hydrodynamics drag

The aim of this study was to analyze the effect of depth on the hydrodynamic drag coefficient during the passive underwater gliding after the starts and turns. The swimmer hydrodynamics performance was studied by the application of computational fluid dynamics (CFD) method. The steady-state CFD simulations were performed by the application of k - omega turbulent model and volume of fluid method to obtain two-phase flow around a three-dimensional swimmer model when gliding near water surface and at different depths from the water surface. The simulations were conducted for four different swimming pool size, each with different depth, i.e., 1.0, 1.5, 2.0 and 3.0 m for three different velocities, i.e., 1.5, 2.0 and 2.5 m/s, with swimmer gliding at different depths with intervals of 0.25 m, each starting from the water surface, respectively. The numerical results of pressure drag and total coefficients at individual average race velocities were obtained. The results showed that the drag coefficient decreased as depth increased, with a trend toward reduced fluctuation after 0.5m depth from the water surface. The selection of the appropriate depth during the gliding phase should be a main concern of swimmers and coaches.

Numerical Simulation of Two-Phase Flow Around Flatwater Competition Kayak Design-Evolution Models

The aim of the current study was to analyze the hydrodynamics of three kayaks: 97-kg-class, single-rower, flatwater sports competition, full-scale design evolution models (Nelo K1 Vanquish LI, LII, and LIII) of M.A.R. Kayaks Lda., Portugal, which are among the fastest frontline kayaks. The effect of kayak design transformation on kayak hydrodynamics performance was studied by the application of computational fluid dynamics (CFD). The steady-state CFD simulations where performed by application of the k-omega turbulent model and the volume-of-fluid method to obtain two-phase flow around the kayaks. The numerical result of viscous, pressure drag, and coefficients along with wave drag at individual average race velocities was obtained. At an average velocity of 4.5 m/s, the reduction in drag was 29.4% for the design change from LI to LII and 15.4% for the change from LII to LIII, thus demonstrating and reaffirming a progressive evolution in design. In addition, the knowledge of drag hydrodynamics presented in the current study facilitates the estimation of the paddling effort required from the athlete during progression at different race velocities. This study finds an application during selection and training, where a coach can select the kayak with better hydrodynamics.