Simulated Race Research Articles

Calcium propionate is an alkalizing agent in exercising Standardbreds.

The objective of this study was to determine if calcium propionate is an alkalizing agent in exercising Standardbreds and if it alters plasma glucose and serum insulin concentrations. This study used a randomized crossover design to test the hypotheses that calcium propionate alters total CO2 (tCO2), Ca++, pH, strong ion difference (SID), glucose, and insulin in Standardbreds completing a simulated race test (SRT) on a high-speed equine treadmill. Blood was collected from eight horses (mean age ± SD = 16 ± 2.7 years; range = 13 - 21 years) at 10 and 5 min prior to treatment or control administration, just prior to the subsequent SRT, directly after the SRT, and at 60- and 90-min post SRT. Plasma pH and plasma concentrations of tCO2, glucose, Ca++, and Na+, K+, Cl-, Lac- (for SID calculation) were measured in duplicate by blood gas analyzer and serum insulin by radioimmunoassay. Data were analyzed by two-way repeated-measures ANOVA. For plasma pH, Na+, K+, Cl-, Lac-, SID, insulin and glucose, no effects of treatment or treatment by sampling-timepoint interaction were found (p>0.05). Plasma tCO2, Ca++, pH, Na+, SID, and glucose concentrations were significantly lower, and Lac- was significantly higher, directly after the SRT compared to all other timepoints (p<0.05). Plasma tCO2, HCO3- and Ca++ were significantly higher in treated than in control horses at multiple sampling timepoints after treatment/control administration (p<0.05). Serum insulin concentration, measured only pre and 30 min post treatment/control administration, was unaffected by treatment. Calcium propionate is an alkalizing agent in horses.

A Comparison of Paddle Forces between Whitewater and Flatwater Training in C1 Canoe Slalom.

Becoming an elite canoe slalom athlete requires thousands of hours of training, spread over many years. It is difficult to assess the correct balance between flatwater and whitewater training because differences in the paddle forces on these terrains are not known. The aim of this study was to describe paddle forces during canoe slalom training on flatwater and whitewater courses for the C1 canoe category. Paddle forces for twenty C1 canoe slalom athletes were quantified during all-out figure-of-eight tests on a flatwater course and during race simulations on a whitewater course. Paddle forces were measured using strain gauges embedded in the paddle shaft and quantified by their force, impulse, and stroke durations. The mean force during the pull phase of the paddle strokes was not significantly different between the flatwater and whitewater courses; however, the longer pull phase durations led to a greater pull phase impulse when paddling on the whitewater course. This study indicates that training for all-out runs on a whitewater course is more demanding for canoe slalom athletes than performing all-out trials on a flatwater figure-of-eight course. This evidence may help to develop effective training plans that are essential to reach the highest levels of the sport.

Performance and Fatigue Patterns in Elite Cyclists During 6 h of Simulated Road Racing.

Fatigue resistance is vital for success in elite road cycling, as repeated, intense efforts challenge the athletes' ability to sustain peak performance throughout prolonged races. The present study combined recurrent performance testing and physiological measures during 6 h simulated racing with laboratory testing to investigate factors influencing fatigue resistance. Twelve male national elite cyclists (25 ± 3 years; 76 ± 6 kg and VO2max of 5.2 ± 0.5 L/min) completed incremental power and maximal fat oxidation tests. Subsequently, they underwent field testing with physiological measures and fatigue responses evaluated through peak sprint power and 5 km time trial (TT) testing after 0, 2, 4, and 6 h of exercise. Peak power declined from 1362 ± 176 W in first sprint to 1271 ± 152 W after 2 h (p < 0.01) and then stabilized. In contrast, TT mean power gradually declined from 412 ± 38 W in the first TT to 384 ± 41 W in the final trial, with individual losses ranging from 2% to 14% and moderately correlated (r2 = 0.45) to accumulated exercise time above lactate threshold. High carbohydrate intake (~90 g/h) maintained blood glucose levels, but post-TT [lactate] decreased from 15.1 ± 2 mM to 7.1 ± 2.3 mM, while fat oxidation increased from 0.7 ± 0.3 g/min at 0 h to 1.1 ± 0.1 g/min after 6 h. The study identifies fatigue patterns in national elite cyclists. Peak sprint power stabilized after an initial impairment from 0 to 2 h, while TT power gradually declined over the 6 h simulated race, with increased differentiation in fatigue responses among athletes.

Less Is More: Higher-Skilled Sim Racers Allocate Significantly Less Attention to the Track Relative to the Display Features than Lower-Skilled Sim Racers.

Simulated (sim) racing is an emerging esport that has garnered much interest in recent years and has been a relatively under-researched field in terms of expertise and performance. When examining expertise, visual attention has been of particular interest to researchers, with eye tracking technology commonly used to assess visual attention. In this study, we examined the overt visual attention allocation of high- and low-skilled sim racers during a time trial task using Tobii 3 glasses. In the study, 104 participants were tested on one occasion, with 88 included in the analysis after exclusions. Participants were allocated to either group according to their fastest lap times. Independent t-tests were carried out with sidak corrections to test our hypotheses. Our results indicate that when eye tracking metrics were normalised to the lap time and corner sector time, there was a difference in the relative length of overt attention allocation (fixation behaviour) as lower-skilled racers had significantly greater total fixation durations in laps overall and across corner sectors when normalised (p = 0.013; p = 0.018). Interestingly, high- and low-skilled sim racers differed in where they allocated their attention during the task, with high-skilled sim racers allocating significantly less overt attention to the track relative to other areas of the display (p = 0.003). This would allow for higher-skilled racers to obtain relatively more information from heads-up display elements in-game, all whilst driving at faster speeds. This study provides evidence that high-skilled sim racers appear to need significantly less overt attention throughout a fast lap, and that high- and low-skilled sim racers differ in where they allocate their attention while racing.

Shifting the Energy Toward Los Angeles: Comparing the Energetic Contribution and Pacing Approach Between 2000- and 1500-m Maximal Ergometer Rowing.

To compare the energetic contribution and pacing in 2000- and 1500-m maximal rowing-ergometer performances. On separate visits (>48 h apart, random order), 18 trained junior (16.7 [0.4]y) male rowers completed 3 trials: a7 × 4-minute graded exercise test, a2000-m time trial (TT2000), and a1500-m TT (TT1500). Respiratory gases were continuously measured throughout each trial. The submaximal power-to-oxygen-consumption relationship from the graded exercise test was used to determine the accumulated oxygen deficit for each TT. Differences in mean power output (MPO), relative anaerobic contribution, percentage of peak oxygen uptake, pacing index, maximum heart rate, rating of perceived exertion, and blood lactate concentration were assessed using linear mixed modeling. Compared to TT2000 (324 [24]W), MPO was 5.2% (3.3%) higher in TT1500 (341 [29W]; P < .001, ηp2=.70). There was a 4.9% (3.3%) increase (P < .001, ηp2=.71) in anaerobic contribution from 17.3% (3.3%) (TT2000) to 22.2% (4.3%) (TT1500). Compared to TT1500, maximum heart rate, rating of perceived exertion, and blood lactate concentration were all greater (P < .05) in TT2000. The pacing index was not different between trials. Percentage increase in MPO from TT2000 to TT1500 was negatively associated with pacing variance in TT1500 (R2 = .269, P = .027). Maximal ergometer performance over 1500m requires a significantly greater anaerobic contribution compared with 2000m. Junior male athletes adopt a consistent pacing strategy across both distances. However, those who experienced greater percentage increases in MPO over the shorter test adopted a more even pacing strategy. To prepare for 1500-m performance, greater emphasis should be placed on developing capacity for work in thesevere domain and completing race simulations with a more even pacing strategy.

Automatic Detection of Faults in Simulated Race Walking from a Fixed Smartphone Camera

Abstract Automatic fault detection is a major challenge in many sports. In race walking, judges visually detect faults according to the rules. Hence, automatic fault detection systems will help a training of race walking without experts’ visual judgement. Some studies have attempted to use sensors and machine learning to automatically detect faults. However, there are problems associated with sensor attachments and equipment such as a high-speed camera, which conflict with the visual judgement of judges, and the interpretability of the fault detection models. In this study, we proposed an automatic fault detection system for non-contact measurement. We used pose estimation and machine learning models trained based on the judgements of multiple qualified judges to realize fair fault judgement. We verified them using smartphone videos of normal race walking and walking with intentional faults in several athletes including the medalist of the Tokyo Olympics. The results show that the proposed system detected faults with an average accuracy of over 90%. We also revealed that the machine learning model detects faults according to the rules. In addition, the intentional faulty walking movement of the medalist was different from that of other walkers. This finding informs realization of a more general fault detection model.

Evaluation of the effects of medium-term (57-day) omeprazole administration and of omeprazole discontinuation on serum gastrin and serum chromogranin A concentrations in the horse.

Rebound gastric hyperacidity (RGH) secondary to hypergastrinemia has been suggested to contribute to the rapid recurrence of equine squamous gastric disease (ESGD) in horses after discontinuation of omeprazole. To evaluate changes in serum gastrin and chromogranin A (CgA) concentrations in response to medium-term (57-day) omeprazole treatment and after omeprazole discontinuation. Fourteen mature Thoroughbred racehorses in simulated race training. Horses received 2.28 g of oral omeprazole PO q24h for 57 days within a 61-day period, excluding a withholding period applied mid-protocol during which treatment was stopped as part of a concurrent study. Serum samples were collected on day 0 before omeprazole treatment, on day 1 of each week of the treatment period, and for an additional 5 weeks after discontinuation of treatment. Serum gastrin and CgA concentrations were analyzed using radioimmunoassay (RIA) and ELISA, respectively. Median serum gastrin concentrations increased 2.5-fold from baseline to day 7 (P < .001) but did not increase further during the omeprazole treatment period. Median serum gastrin concentrations returned to baseline within 2 to 4 days after administration of the last dose of omeprazole. No effect of treatment or discontinuation was seen in serum CgA concentrations. Serum gastrin concentrations increased in response to omeprazole treatment but returned to baseline within 2 to 4 days after the last dose of omeprazole. No effect of treatment or discontinuation was seen in serum CgA concentrations. Our results do not support the use of tapering protocols in horses.

Prompted hands-free drinking improves simulated race car driving in a hot environment

ABSTRACT Race car drivers are often hypohydrated during a race. The FluidLogic drink system is a hands-free, prompted drinking system that is hypothesized to increase the likeliness of drivers’ consuming fluids and thereby mitigating hypohydration. To test the hypothesis, 20 elite professional race car drivers participated in a 2-day cross-over study in which they drove on a race simulator in an environmental chamber that was heated to regulation cockpit temperature (38°C). Drivers used either the FluidLogic drink system or a standard in-car water bottle system (Control) on one of each testing day. The results indicated that there was consistent fluid consumption with the FluidLogic system, while the Control condition elicited fluid consumption in bolus doses. The Control condition was associated with moderate (0.5%) increased core body temperature (P < 0.05) and substantial (3.3%) increased urine-specific gravity (P < 0.001) as compared to the FluidLogic condition. Driving performance metrics indicated that lap times during the Control Condition were 5.1 ± 1.4 (4.1%) seconds slower (P < 0.05) than the FluidLogic Condition, due to driving errors that occurred in the high-speed corners. Based on these results, prompted hands-free drinking can mitigate hypohydration and performance loss in automobile racing drivers.

Kinematical effects of rifle carriage on roller skiing in well-trained female and male biathletes.

This study aimed to investigate how rifle carriage and skiing speed during biathlon roller skiing affect range of motion (ROM) in joint angles and equipment (skis and poles), the vertical distance between shoulders and treadmill (vertdist ), as well as possible sex differences associated with rifle carriage. Fourteen biathletes (6 women, 8 men) roller-skied on a treadmill at submaximal and simulated race speeds, with (WR) and without (NR) a rifle, using gears 3 and 2. Kinematical data for the whole body, poles, roller-skis, rifle, and treadmill were monitored using a 3D motion capture system. Movements determined as flexion/extension (x), abduction/adduction (y), and/or internal/external rotation (z) were analyzed for the hip, shoulder, thorax, knee, ankle, elbow, poles, and roller skis. ROM (the difference between maximal and minimal angles) in joints and equipment, and vertdist were analyzed over six skiing cycles during each condition (WR and NR) and speed. The maximal vertdist was lower for WR compared with NR (gear 3: 1.53 ± 0.06 vs 1.54 ± 0.06 m; gear 2: 1.49 ± 0.06 vs 1.51 ± 0.06 m; both p < 0.001). ROM in the upper body was altered when roller skiing WR (movements decreased in thorax and shoulder (x) and increased in elbow (only gear 3) (x), thorax (only gear 2), and shoulder (y) and (z); all p < 0.05) and increased with speed, without differences between sexes (p > 0.05). Since rifle carriage and speed appear to affect the kinematics of roller skiing, coaches, and biathletes are advised to perform skiing technique training under competition-like conditions (i.e., at race speeds while carrying the rifle).

Acoustic Indicators for Motor Race Noise: Definition, Validation, and Tests in Simulated and Real Races

Although the road transport sector, together with railways, airports, and industries represent the major contributors to noise pollution in Europe, also other minor activities, scarcely explored in the literature, can have a non-negligible role on a local scale. This is the case of motorsport races. During these types of events, vehicles produce notable noise emissions while are on track during tests, qualifying, and race sessions. As a consequence, they may, directly or indirectly, affect the well-being of inhabitants in the surrounding area of the circuit, and expose the public, workers, and all the other possible Noise Sensitive Receivers (NSRs) to high noise levels. Therefore, a thorough analysis of the noise levels produced during motorsport events at sensible receivers is strongly needed, to better assess NSRs’ exposure and gather information on the possible measures to reduce noise to acceptable levels.This works aims to address this topic, by proposing the definition of two noise indicators: the Lap Equivalent Level (LEL) and the Race Equivalent Level (REL). LEL defines the equivalent noise level at a certain receiver due to a single-vehicle track lap, and REL the equivalent noise level produced during a race.Noise data were collected on different points along a racing circuit during a single-vehicle track test and different car races, to apply in practice the defined indicators. Measurements show that the REL tends to stabilize its values during a race, suggesting that its modeling can be achieved based on the average LEL and the number of vehicles participating in a race. Instead, the duration of the race does not play a key role in the estimation of REL values but, rather, gives information on the NSRs’ exposure time to race noise levels. Estimations of RELs were carried out for real and simulated races. A comparison with available measured values shows good performance of the indicators suggesting that the proposed approach could be appropriate.

Prolonged cycling lowers subsequent running mechanical efficiency in collegiate triathletes

BackgroundA significant challenge that non-elite collegiate triathletes encounter during competition is the decline in running performance immediately after cycling. Therefore, the purpose of this study was to determine if performing a 40-km bout of cycling immediately before running would negatively influence running economy and mechanical efficiency of running during simulated race conditions in collegiate triathletes.MethodsEight competitive club-level collegiate triathletes randomly performed two trials: cycling for 40 km (Cycle-Run) or running for 5 km (Run–Run), immediately followed by a four-minute running economy and mechanical efficiency of running test at race pace on an instrumented treadmill. Blood lactate, respiratory exchange ratio, mechanical work, energy expenditure, and muscle glycogen were also measured during the four-minute running test.ResultsMechanical efficiency of running, but not running economy, was significantly lower in Cycle-Run, compared to Run–Run (42.1 ± 2.5% vs. 48.1 ± 2.5%, respectively; p = 0.027). Anaerobic energy expenditure was significantly higher in the Cycle-Run trial, compared to the Run–Run trial (16.3 ± 2.4 vs. 7.6 ± 1.1 kJ; p = 0.004); while net (151.0 ± 12.3 vs. 136.6 ± 9.6 kJ; p = 0.204) and aerobic energy expenditure (134.7 ± 12.3 vs. 129.1 ± 10.5 kJ; p = 0.549) were not statistically different between trials. Analysis of blood lactate, respiratory exchange ratio, mechanical work, and changes in muscle glycogen revealed no statistically significant differences between trials.ConclusionsThese results suggest that mechanical efficiency of running, but not running economy, is decreased and anaerobic energy expenditure is increased when a 40-km bout of cycling is performed immediately before running in collegiate triathletes.

Optimal Design of Suspension System of Four-wheel Drive Baja Racing

In order to match the four-wheel drive system of Baja racing, improve the handling stability and driving comfort of the car, and optimize the parameter design of the suspension. Establish a suspension system model in ADAMS, conduct motion simulation, analyze important suspension parameters, modify the suspension hard points according to the analysis results, and optimize the suspension parameters. Finally, a set of excellent suspension parameters is obtained, and the performance of the suspension system can be improved. The suspension parameters of the simulated racing car have been determined, and other performance parameters have also been improved through hard-point modification. Using ADAMS to perform motion simulation of the suspension system saves time and can efficiently realize the optimal design of the suspension system.

Is the Most Commonly Used Strategy for the First 1,500 m of a 2,000 m Rowing Ergometer Race the Most Appropriate?

This study investigated time-courses of physiological and psychological parameters of rowers during the first 1,500 m of a simulated race on a rowing ergometer using different pacing strategies. This provided a picture of the physiological and psychological state of the rowers at the start of the last 500 m of their race. Investigated strategies corresponded either to a degressive (degr), a progressive (prog), or a stable (stab) power output over the traveled distance. Thirteen French rowers (4 oarswomen and 9 oarsmen) of national and ex-international levels volunteered to participate. Handle force and velocity, oxygen uptake, heart rate, blood lactate concentration, and peripheral oxygen saturation were measured during the trials. Power output, generated energy [by O2 consumption (Eoxi) and blood lactate accumulation (Enon−oxi)] and efficiency were computed. Rowers also rated their perceived exertion (RPE) and protocol preference. In the explored strategies, no significant differences were found for Eoxi. Final blood lactate concentration ([La]blood) and RPE were similar for all strategies. However, the increase in [La]blood and RPE occurred sooner for degr than for stab and prog. Therefore, the time spent at higher [La]blood and RPE was longer for degr than for stab and prog. According to the questionnaire, degr was the least preferred protocol. While during 2000 m races, the first 1500 m are usually and empirically often conducted in a degr way, the present results indicate that this strategy was the least preferred by the rowers and led to a higher time spent at high [La]blood and RPE.

Association of Heart Rate Variability and Simulated Cycling Time Trial Performance

The aim of this study was to determine if an abnormal HRV status would have negative effects on simulated individual time trial (ITT) performance in recreational cyclists. Recreational male (n=23, 42.8±8.3 years, 78.0±11.0 kg) and female (n=2, 37.0±6.8 years, 68.0±4.4 kg) cyclists completed simulated indoor 40-minute ITTs (40TT) over ten weeks. Participants were asked to complete simulated 40TTs under two HRV conditions: HRV normal values and HRV abnormal values. Participants recorded daily morning HRV readings to determine HRV status. Each participant performed all 40TTs on their personal indoor bike trainer and bike without external race simulation (e.g., Zwift). All cycling performance data were recorded on personal bike computers and submitted via a Qualtrics survey. A total of 138 ITTs (Normal = 75; Abnormal = 63) were assessed for relationships between HRV status and performance outcomes using a linear mixed-effects model with Cohen’s D for effect sizes (ES). A significant main effect of HRV status was found for peak power (F = 6.61; Normal: 372 ± 121.5 watts; Abnormal: 349 ± 105.9 watts; 380; p = 0.01; ES = 0.20) and peak speed (F = 6.12; Normal = 10.8 ± 1.2 m/s; Abnormal: 10.4 ± 1.2 m/s; p = 0.02; ES = 0.33). No significant main effect or effect sizes exceeding 0.20 were observed for all other performance variables. Daily HRV monitoring provides valuable insight that an individual’s peak power and speed may be compromised during cycling performance despite no changes in physiological or psychological indicators of effort. Coaches and cyclists can use morning HRV to inform race strategy ensuring desired performance outcomes, especially for those who rely on high power outputs

The Relationship between Stroke Metrics, Work Rate and Performance in Slalom Kayakers

The purpose of this study was to assess the relationship between work rate, stroke metrics, and performance in whitewater slalom. Twelve Spanish, nationally competitive whitewater slalom kayakers took part in a simulated competition while using an instrumented kayak paddle to record stroke metrics over a simulated race, total duration and sectional splits. Performance time was highly correlated to overall power output (r2 = 0.511, p &lt; 0.001), where kayakers demonstrated a positive pacing strategy with power output significantly decreasing over successive sectional splits (158 ± 40, 112 ± 32 and 65 ± 33 W, p &lt; 0.001). This resulted in an increased stroke duration (p &lt; 0.001), time to peak force (p &lt; 0.001), a decrease in stroke peak force (p &lt; 0.001), and rate of peak force development (p &lt; 0.001) over elapsed time. As such, work rate is deemed an objective metric to monitor performance, prescribe training, and ascertain optimal pacing strategies in canoe slalom.

‘I Know What It's Like’: Epistemic Arrogance, Disability, and Race

AbstractUnderstanding and empathy on the part of those in privileged positions are often cited as powerful tools in the fight against oppression. Too often, however, those in positions of power assume they know what it is like to be less well off when, in actuality, they do not. This kind of assumption represents a thinking vice we dub synecdoche epistemic arrogance. In instances of synecdoche epistemic arrogance, a person who has privilege wrongly assumes, based on limited experiences, that she can know what it is like to experience a particular form of oppression. We argue two main points. First, synecdoche epistemic arrogance can lead to a variety of moral harms. Second, synecdoche epistemic arrogance is often tied to other troubling epistemic patterns, which we discuss in the context of disability and race simulations. Overall, the essay helps demonstrate how synecdoche epistemic arrogance can contribute to injustice.

Artificial Intelligence‐Based Real‐Time Signal Sample and Analysis of Multiperson Dragon Boat Race in Complex Networks

Dragon boat sport is a traditional activity in China. In recent years, dragon boat sport has become more and more popular around the world. In order to face more challenges, it is urgent for athletes to enhance their own strength. Scientific training methods are particularly important for athletes, and accurate training data are the basis to support scientific training. Traditional mathematical statistic methods neither can sample signals accurately nor can they do real‐time analysis and feedback the characteristics to each athlete. In this paper, we use the wearable device with a triaxial accelerometer and heart rate sensor builtin to sample the speed signals and heart rate signals of athletes in various stages of men’s 1000m straight race. Based on the complex network theory, we regard the 23 dragon boat athletes in the dragon boat race as 23 nodes so as to establish a network with 23 nodes and reflect the importance of nodes by measuring the impact of node deletion on the results of the race. The neural network multilayer perceptron (MLP) model is used for training to obtain the optimal combined value with speed and heart rate for each race stage. The optimal value will be used in the simulated race as the target value to verify if it can help to improve the training efficiency. Experimental results show that the optimal value obtained by this method has a positive effect on the results of the dragon boat race which is beneficial to sports training and tactics planning.

Change in the activity of trunk and lower limb muscles during 2000-m rowing.

This study aimed to clarify the changes in the activity of the trunk and lower limb muscles during 2000-m rowing. Ten male rowers performed a 2000-m race simulation on a rowing ergometer. Electromyography results of the abdominal muscles, back muscles, gluteus maximus (GMax), biceps femoris (BF), and rectus femoris (RF) were recorded. The electromyographic activity during the three strokes after the start (initial stage), at 1000m (middle stage), and before the end (final stage) were analyzed. From the handle position, the rowing motion was divided into five phases (early-drive, middle-drive, late-drive, early-recovery, and late-recovery). The peak activities of the abdominal muscles, back muscles, GMax, and BF in each stroke of the rowing motion were delayed at the middle and final stages compared to the initial stage (P<0.05). The peak activity of the RF was observed in the late-drive phase at the initial stage, whereas a high RF activity was observed in the middle-drive phase at the middle and final stages (P<0.05). Considering the results of the activity of the back muscles and RF, RF muscular endurance enhancement may lead to a decrease in the load on the back muscles and help prevent muscular low back pain in rowers. J. Med. Invest. 69 : 45-50, February, 2022.

Effect of mental fatigue on mean propulsive velocity, countermovement jump, and 100-m and 200-m dash performance in male college sprinters

The objective of this study was to analyze the effect of mental fatigue on mean propulsive velocity (MPV), countermovement jump (CMJ), 100, and 200-m dash performance in college sprinters. A total of 16 male athletes of sprint events (100 and 200-m dash) participated in this study. Each participant underwent two baseline visits and then running under the three experimental conditions. Assessments (MPV and CMJ) occurred both before and after either smartphone use (SMA) or Stroop task (ST), or watching a documentary TV show about the Olympic Games (CON). Then, the athletes ran the simulated race (i.e. the 100 and 200-m dash). There was no condition (p > 0.05) or time effect (p > 0.05) for MPV, CMJ, 100-m, or 200-m dash performance. In conclusion, the present study results revealed no mental fatigue effect induced by SMA or ST on neuromuscular, 100-m or 200-m dash performance in male college sprinters.

Carbohydrate supplementation during a simulated 10-km open water swimming race: effects on physiological, perceptual parameters and performance.

ABSTRACT The aim of the present study was to test the effect of carbohydrate ingestion, simulating a 10-km open water race competition on energy cost (Csw), perceived exertion (RPE), heart rate (HR), stroke rate (SR) and performance. We hypothesized that carbohydrate ingestion would reduce Csw and RPE in elite open water swimmers (OW-swimmers) and improve performance. Eight elite OW-swimmers swam for 3 × 30 min with 20-s of interval necessary to collect data in the swimming flume at a pre-set pace corresponding to their 10-km race pace, followed by a time to exhaustion test (TTE) at 100% of the peak oxygen uptake (V̇O2peak). During the set, OW-swimmers ingested 45-g of carbohydrates (CHO) in 550-mL of water (8% solution) during each of the two intervals or a placebo solution (PLA). HR, RPE, V̇O2 and SR were measured. Shapiro–Wilk test was used to verify the normal distribution of data. Two-way repeated measures ANOVA and t-test was performed (p < 0.05). A significant difference emerged in TTE between the trials (169.00 ± 91.06 s in CHO; 102.31 ± 57.47 s in PLA). HR, RPE and SR increased during the TTE but did not differ between trials. Csw did not show a significant main effect between the two conditions and in time course in both conditions. CHO ingestion significantly increased TTE at 100% of V̇O2peak after 90-min of swimming at 10-km race pace. These findings indicate that CHO intake during a 10-km open water swimming competition should have a beneficial impact on performance in the final part of the race.