Distance Runners Research Articles

Effectiveness of an innovative athletic program at the 1st stage of primary school

The aim of the experiment was to test the effectiveness of an innovative program in grade 3 of elemantary school and to compare the results with a traditional teaching program for lower stage of elementary school. The experiment took place at the Ďumbierska primry School in Banská Bystrica. One class was randomly assigned as an experimental group, in which teaching in the form of an innovative programme took place, and the other as a control group, in which teaching in the traditional way took place. Subsequently, the application of the innovative programme was carried out in the scope of 9 lessons. A 5-point scoring scale was developed to assess athletic skills. SPSS Statistic statistical program was used to detect statistical significance and the results were evaluated at α ≤ 0.05 level. The pupils of the experimental group achieved a significant improvement in sports skills compared to the control group, which was confirmed by calculating the statistical significance. The most significant improvement was recorded in short distance running, where pupils of the experimental group improved by 32%. In short distance running, the most significant differences between the experimental and control group were also recorded, by 20%. In the standing long jump, an improvement of 23.5% was recorded, with a more significant improvement of 19% compared to the control group. The least significant differences were recorded in cricket ball throwing, where the experimental group improved by 16.75%, 13% more than the control group. Based on the results, we recommend incorporating more innovative exercises, exercises in pairs and movement games, following the methodological procedures, incorporating more teaching aids to make the lesson more varied and fun for the pupils.

Does curcumin supplementation affect inflammation, blood count and serum brain-derived neurotropic factor concentration in amateur long-distance runners?

Curcumin is known for its potential health benefits; however, the evidence remains inconclusive regarding its necessity as a supplement for athletes during the preparatory phase of training. This study aimed to assess the effect of 6-week curcumin supplementation at a dose of 2g/day on selected inflammatory markers, blood count, and brain-derived neurotropic factor (BDNF) levels in middle-aged amateur long-distance runners during the preparatory period of a macrocycle. Thirty runners were randomly assigned to either a curcumin-supplemented group (CUR, n = 15) or a placebo group (PLA, n = 15). Venous blood samples were collected at rest, immediately post-exercise, and 1h post-exercise. The participants underwent a graded exercise stress test, with an increasing inclination angle after reaching a speed of 14 km/h, both before and after the 6-week supplementation period. Blood samples were collected at rest, 3 minutes post-stress test, and after 1 hour of recovery. The results showed no significant changes in C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), interleukin-1 β (IL-1β), or blood morphology due to curcumin supplementation. However, BDNF levels increased by 21% in the CUR group post-supplementation, while a 5% decrease was observed in the PLA group. These findings do not support a significant effect of curcumin supplementation on inflammatory markers, blood count, or BDNF concentration. Further research is warranted to determine the potential benefits of curcumin supplementation for endurance athletes during the preparatory period for a training cycle.

A session-by-session analysis of psychological and external workload demands prior to muscle-tendon injuries in Brazilian professional soccer players: a pilot study

ABSTRACT Objectives This study aimed to compare the psychological demands and external workload experienced in the seven sessions leading up to injuries and the demands in the month preceding the injury week among professional Brazilian soccer players. Methods Initially, 33 players participated, but only 15 were included in the analysis due to the occurrence of twenty-three muscle-tendon injuries recorded according to International Olympic Committee (IOC) guidelines. The study assessed muscle-tendon injuries, rate of perceived exertion (RPE), and psychological variables (i.e. mental load, motivation, and mental fatigue) using specific questionnaires, while weekly accumulated workload (i.e. total distance, high-speed running distance, sprint running distance, number of sprints, and actions accelerating and decelerating) was recorded using Global Position System devices. Results The results indicated that players experienced higher external loads, particularly in high-intensity running variables, along with increased mental load and mental fatigue during the match prior to injury occurrence (p < 0.05). Conclusion These findings highlight the significance of carefully monitoring both external and psychological demands during competition, which is essential for developing effective recovery strategies and modulate the subsequent microcycle training loads in order to reduce the risk of suffer a muscle-tendon injury.

Influence of cadence manipulation on running biomechanics in high school cross-country runners

ABSTRACT Increasing cadence is an intervention to reduce injury risk for adolescent long-distance runners. It is unknown how adolescents respond biomechanically when running with a higher than preferred cadence. We examined the influence of increasing cadence on peak joint angles, moments and powers, and ground reaction forces in long-distance runners. We collected three-dimensional kinematics and kinetics for 31 high school cross-country runners during overground running at their preferred cadence (baseline), +5%, and +10% baseline cadence. We performed repeated-measures ANOVAs to compare peak joint angles, moments and powers, and ground reactions forces among cadence conditions. Increasing cadence reduced peak pelvis, hip, knee, and ankle joint angles (p ≤ .01), peak knee moment and powers (p < .001), peak ankle power (p ≤ .01), and peak ground reaction forces (p ≤ .01) but increased peak hip moment and powers (p < .001). Increasing cadence by 10% elicited greater magnitude changes compared to increasing cadence by 5%. Increasing cadence may be a beneficial intervention to reduce lower extremity peak joint angles and knee kinetics for adolescent long-distance runners. The increase in hip kinetics when running at a higher than preferred cadence indicates this intervention increases the loads applied to the hip for adolescent long-distance runners.

Evaluating the Biomechanical Effects and Real-World Usability of a Novel Ankle Exo for Runners.

Achilles tendon overuse injuries are common for long-distance runners. Ankle exos (exoskeletons and exosuits) are wearable devices that can reduce Achilles tendon loading and could potentially aid in the rehabilitation or prevention of these injuries by helping to mitigate and control tissue loading. However, most ankle exos are confined to controlled lab testing and are not practical to use in real-world running. Here, we present the design of an unpowered ankle exo aimed at reducing the load on the Achilles tendon during running while also overcoming key usability challenges for runners outside the lab. We fabricated a 500-gram ankle exo prototype that attaches to the outside of a running shoe. We then evaluated the reliability, acceptability, transparency during swing phase, and offloading assistance provided during treadmill and outdoor running tests. We found that the exo prototype reliably assisted 95-99% of running steps during indoor and outdoor tests, was deemed acceptable by more than 80% of runners in terms of comfort and feel, and did not impede natural ankle dorsiflexion during leg swing for 86% of runners. During indoor tests, the exo reduced Achilles tendon loads for most participants during running; however, reductions varied considerably, between near zero and 12%, depending on the participant, condition (speed and slope) and the precise tendon load metric used. This next-generation ankle exo concept could open new possibilities for longitudinal and real-world research on runners, or when transitioning into the return-to-sport phase after an Achilles tendon injury.

The influence of prolonged aerobic exercise on cardiac, muscular, and renal biomarkers in trained individuals with obesity.

The aim of this study was to investigate the influence of prolonged aerobic exercise on cardiac, muscular and renal inflammatory markers in a group of trained obese men. Seventeen men (aged 40 ± 6years; body mass index [BMI] 31.3 ± 2.8kgm-2, maximal oxygen uptake [V'O2max] 41.5 ± 5.6mlkg-1min-1) ran a half, 30km, or full marathon. Troponin I (cTnI), the n-terminal creatine kinase-myocardial band (CK-MB), pro b-type natriuretic peptide (NT-proBNP), lactate dehydrogenase (LDH), myoglobin, creatinine (CREA) and the estimated glomerular filtration rate (eGFR)were measured before (T0), immediately after (T1) and 3days after the race (T2). The concentrations of cTnI, myoglobin, LDH, CK-MB and CREA significantly increased (P < 0.05), whereas eGRF decreased at T1 (P < 0.05). All the above parameters returned to baseline at T2, except for eGFR, which remained lower than that at T0 (P < 0.05). A positive association was observed between ΔCK-MB (%) and the time spent in Zone 3 during the race (R = 0.686, P = 0.014). The Δmyoglobin (%) was positively correlated with race time, race mean speed and time in Zone 3 (R = 0.574-0.862, P < 0.05). The ∆CREA values were moderately correlated with the race mean HRMAX (%) and time spent in Zone 3 (%) (R = 0.514-0.610; P = 0.05). The ∆eGRF values were moderately inversely correlated with the time spent in Zone 3 (%) (R = - 0.627; P < 0.05). Changes in cardiac, muscular and renal inflammatory markers in trained men with obesity are consistent with those described in the literature in normal-weight individuals. Finally, running parameters, such as running time, average running intensity and time in Zone 3 appear to be responsible for the changes in cardiac, muscular and renal function markers after long-distance running.

Exploring the impact of high altitude on physiological parameters and training characteristics of endurance runners.

Exploring the impact of high altitude on physiological parameters and training characteristics of endurance runners.

Pre-race medical clearance in 60,609 distance running race entrants: which entrants sought clearance, what physicians did, and what was the outcome? SAFER XXXVII.

Medical clearance is often recommended for athletes prior to endurance exercise. The primary aim was to determine the percentage (%) of race entrants that sought medical clearance prior to participation in endurance running events, describe the diagnostic modalities used by doctors to assess entrants seeking medical clearance, and the clearance advice given. Secondary aims were to investigate the factors associated with seeking and outcome of clearance. All consenting race entrants who completed an online screening questionnaire during registration to participate in the 21.1 km or 56 km Two Oceans marathon races from 2013-2015 (N.=60,609) were included. Runners were stratified into four risk categories: low risk (LR), intermediate risk (IR), high risk (HR) and very high risk (VHR). Runners were asked if they consulted with a medical doctor to obtain medical clearance. Follow-up questions enquired about what the doctor did when they sought medical clearance and what advice the doctor gave as an outcome of the medical clearance consultation. Prevalence (%, 95% CI) and Prevalence Ratios (PRs) are reported. Over the 3-year period, 14.8% of entrants sought medical clearance. For clearance, doctors used history only (9.9%), history and physical examination (36.7%) and history, physical examination, and special investigations (53.0%). Most entrants seeking medical clearance were fully cleared to race (87.7% in 21.1 km and 85.9% in 56 km) (P=0.0156). Factors associated with seeking medical clearance include longer race distance, older age and a higher risk category (P<0.0001). The methods doctors use when conducting medical clearance consultations vary greatly. Further research is suggested to develop a protocol that doctors can use for medical consultations.

Acute Effects of Taurine Supplementation on Maximal Fat Oxidation and FATmax in Recreational Endurance Runners: A Randomized, Placebo-Controlled, Crossover, and Triple-Blinded Study.

Taurine (TAU) has been shown to improve time to exhaustion (TTE) and fat oxidation during exercise; however, no studies have examined the effect of acute TAU supplementation on maximal fat oxidation (MFO) and related intensity to MFO (FATmax). Our study aimed to investigate the effect of acute TAU supplementation on MFO, FATmax, VO2peak, and TTE. Eleven recreationally trained male endurance runners performed three incremental running tests. The first visit included a familiarization to the test, followed by two subsequent visits in which exercise was performed 90min after ingestion of either 6-g TAU or placebo (PLA) using a triple-blind randomized crossover design. There was no effect of TAU on MFO (p = .89, d = -0.07, TAU: 0.48 ± 0.22g/min; PLA: 0.49 ± 0.15g/min or FATmax (p = .26, d = -0.66; TAU: 49.17 ± 15.86 %V˙O2peak; PLA: 56.00 ± 13.27 %V˙O2peak). TTE was not significantly altered (TAU: 1,444.8 ± 88.6s; PLA: 1,447.6 ± 87.34s; p = .65, d = -0.04). TAU did not show any effect on V˙O2peak in comparison with PLA (TAU: 58.9 ± 8.4ml·kg-1·min-1; PLA: 56.5 ± 5.7ml·kg-1·min-1, p = .47, d = 0.48). However, V˙O2 was increased with TAU at most stages of exercise with large effect sizes. The acute ingestion of 6 g of TAU before exercise did not enhance MFO, FATmax, or TTE. However, it did increase the oxygen cost of running fixed intensities in recreationally trained endurance runners.

Role of CTRP14/C1QL1 in motor coordination and learning across the lifespan.

C1q/TNF-related protein 14 (CTRP14), also known as C1q-like 1 (C1QL1), is a synaptic protein predominantly expressed in the brain. It plays a critical role in the formation and maintenance of the climbing fiber-Purkinje cell synapses, ensuring that only one single winning climbing fiber from the inferior olivary neuron synapses with the proximal dendrites of Purkinje cells during the early postnatal period. Loss of CTRP14/C1QL1 results in incomplete elimination of supernumerary climbing fibers, leading to multiple persistent climbing fibers synapsing with the Purkinje cells. While this deficit impairs oculomotor learning in adult mice, the impact of CTRP14 deficiency on motor function throughout adulthood has not been examined. Here, we conduct behavioral tests on a constitutive Ctrp14 knockout (KO) mouse model to determine whether CTRP14 is required for motor learning and function in mice across the lifespan. We show that CTRP14 deficiency does not affect grip strength, nor sprint and endurance running, in young and old mice of either sex. We performed accelerated rotarod tests on mice at 6, 12, and 18 months old to assess motor coordination and learning. No significant differences were observed between WT and Ctrp14-KO mice of either sex across the lifespan. Lastly, we performed complex running wheel tests to detect latent motor deficits and found that aged Ctrp14-KO mice have intact motor skills. Despite some limitations of the study, our data suggest that CTRP14 is dispensable for gross motor skills, coordination, and learning throughout adulthood based on the specific tests performed.

Running trends in Switzerland from 1999 to 2019: An exploratory observational study.

Several single race events (5 km, 10 km, half-marathon, marathon, ultra-marathon) in different countries and different years have been analyzed in multiple studies, representing the rising interest in endurance-based activity and thus physical health. With focus on participation numbers, performance or sex difference, many single study results were obtained. The running trends in a whole country covering a longer period of time and several race distances are missing so far. The aim of this study is therefore to examine 5 km, 10 km, half-marathon, marathon and ultra-marathon races by age, sex, participation numbers and performance during two decades (1999-2019) for one country (Switzerland). In this exploratory observational study, we analyzed 1,172,836 finishers (370,517 women and 802,319 men) competing between 1999 and 2019 in 5 different race distances in Switzerland. We used publicly available data about the athletes and examined total finishing numbers, sex, age and performances (measured in m/s) via descriptive analyses and linear mixed models. Do-not-finishers were excluded. The most frequented race was the half-marathon (33.1% of finishers), the less frequented was the ultra-marathon distance (8.5% of finishers). In most recent years, only the number of finishers in ultra-marathon, especially in trail runs increased. In total, there were more male finishers (68.4%) than female finishers (31.6%) and only in 5 km races, more women finished than men (55.3%). Men were faster than women and both sexes were running slower in all race distances across years. Athletes in 10 km races had the best performance within the five analyzed race distances. Median age increased with longer race distance and decreased in ultra-marathon in recent years. In summary, finishing numbers especially in ultra-marathons increased with a focus on trail runs, female and male athletes had a declining performance across years in all race distances and men ran faster than women. Median age increased with longer race distance leading to more aged endurance-trained athletes. A downtrend in median age is found only in ultra-marathon in recent years. The results are important for athletes, race directors and coaches with regard to training schedules and the trend towards long distance races as well as for the medical attendance especially of older athletes, being more and more interested in endurance running.

Assessment of Relative Energy Deficiency in Sport, Malnutrition Prevalence in Female Endurance Runners by Energy Availability Questionnaire, Bioelectrical Impedance Analysis and Relationship with Ovulation status

Assessment of Relative Energy Deficiency in Sport, Malnutrition Prevalence in Female Endurance Runners by Energy Availability Questionnaire, Bioelectrical Impedance Analysis and Relationship with Ovulation status

Inclined distance running at iso-efficient speeds: Effect on joint work

ABSTRACT Runners often reduce their pace during inclined running to maintain a constant metabolic workload, known as iso-efficiency speed (a speed-incline combination with the same metabolic intensity as level running). This study investigates changes in lower extremity (LE) joint work profiles when running on an incline at iso-efficiency speed. Eleven collegiate distance runners completed a treadmill running task under three conditions (0%, 4%, and 8% incline). Running velocity was reduced with increasing incline to ensure a consistent metabolic workload across conditions. An 8-camera motion capture system and an instrumented treadmill collected kinematics and ground reaction forces. Visual 3D was used to calculate ankle, knee, and hip joint powers, while custom software (MATLAB) calculated ankle, knee, and hip joint positive and negative work values. A significant increase in LE total positive work was attributed to greater ankle and hip joint positive work with steeper inclines. Reduced LE total negative work resulted from lower knee and hip joint negative work as incline increased. Results suggest that at iso-efficiency speeds, inclined treadmill running increases eccentric demands on the ankle joint and concentric demands on the ankle and hip joints, benefiting training programmes to optimize cardiorespiratory stimuli while reducing mechanical demand on specific extremity structures.

The Relationship Among Maximal Aerobic Capacity, Pulmonary Function Tests, and Cognitive Functions in Healthy Middle-Aged Adults

Aim: This study aimed to investigate if maximal aerobic capacity and pulmonary function tests can be a predictor of cognitive function including selective attention and inhibitory response in healthy middle-aged adults. Material and Methods: The study involved 43 people, comprising 31 females and 12 males. The research included evaluations of maximal aerobic capacity (VO2max), pulmonary function tests, and cognitive assessments. VO2max was assessed by the 1-mile Endurance Run/ Walk Test, and pulmonary function evaluations were conducted via a spirometer. Selective attention was measured via the d2 test, whilst inhibitory response was evaluated using a computer-based Go/No-Go test. Results: The TM parameter was not significantly predicted by TM Model 1 (F(4, 38) = 1.324, p = 0.279) or TM Model 2 (F(8, 34) = 1.752, p = 0.122). Similarly, E1 Model 1 did not show statistical significance in predicting the E1 parameter. Analysis of the inhibitory parameters GCR and NGRC also revealed no significant associations, as indicated by GCR Model 1 (F(4, 38) = 0.389, p = 0.815), GCR Model 2 (F(8, 34) = 0.333, p = 0.947), NGRC Model 1 (F(4, 38) = 1.917, p = 0.128), and NGRC Model 2 (F(8, 34) = 2.042, p = 0.071). However, a moderate positive correlation was observed between TM and FEV1 (r = 0.35, p &lt; 0.05). Conclusion: It can be concluded from these results that the VO2max test and the outcomes of the pulmonary function tests are not reliable indicators of cognitive abilities in middle-aged, healthy persons. Nonetheless, FEV1 may function as a marker of selective attention. Additional research involving a larger sample size is needed to better understand the relationship between maximal aerobic capacity, pulmonary function tests, and cognitive performance

The Relationship of Dynamic Foot Posture with Injuries and Other Related Factors in Recreational Long Distance Runners

Foot posture is one of the risk factors that is thought to play a role in the occurrence of running-related injuries. This research aims to see if there is an association between foot posture and running-related injuries in long-distance recreational runners. Methods A cross-sectional research was conducted on 131 recreational long-distance runners (94 men and 42 women). Foot posture was determined by Arch Index values calculated from static and dynamic footprints, then tested whether it was associated with running-related injuries. The results showed that dynamic and static foot posture were not associated with running-related injuries in recreational long-distance runners (OR=0.67(0.21-2.20), 95% CI, p=0.516), (OR=0.87(0.29-2.61), 95% CI, p=0.806). On dynamic examination, low arch and high arch foot postures were not associated with running-related injuries in recreational long distance runners (OR=0.67(0.21-2.19), 95% CI, p=0.508), (OR=0.86(0.07-10.67), 95% CI, p=1.00). Most subjects had low arch foot posture on dynamic (83.8%) and static (82.4%) examination. Running-related injuries were found to be 28.7%, with most injuries in the knee (19.5%), calf (17.9%), and sole (15.6%) areas. The conclusions and suggestions in this research are that dynamic and static foot posture are not associated with running-related injuries in long-distance recreational runners, so further prospective research needs to be done to get a clearer picture of other risk factors that cause running-related injuries.

Differential Gut Microbiome Profiles in Long-Distance Endurance Cyclists and Runners.

We recently have shown that the gut microbiota composition in female and male runners positively correlates with sports, and female runners show similar gut microbiome diversity to male runners. However, gut microbiota composition has not yet been fully investigated in other endurance athletes, such as cyclists. Therefore, in the current study, we investigated the gut microbiome profiles in competitive, non-professional female and male cyclists compared to what we have shown in runners. We aim to understand (1) whether the gut microbiome signature is sport-specific; (2) whether there is a microbiome difference between female and male cyclists and runners; and (3) whether the gut bacteria expressed in cyclists and runners correlates with exercise performance. Our study included 58 subjects: 18 cyclists (9 males), 22 runners (13 males), and 18 control subjects (9 males). Fecal samples were obtained and subjected to taxonomic analysis to assess the relative abundances of species across subjects based on 16S rRNA sequencing results. Both alpha and beta diversity of the bacterial communities were evaluated to identify compositional variations between the groups. Each participant completed a maximal oxygen consumption test and a time-to-exhaustion test at 85% of the measured VO2max. Cyclists performed the test on an SRM ergometer, while runners used a motorized treadmill. Blood lactate levels were measured at 5 min intervals throughout the time-to-exhaustion trials. Alpha diversity demonstrated a significant difference (p-adj < 0.001) between cyclists and runners. Male cyclists showed significantly lower alpha diversity than runners (p-adj < 0.001). The taxonomic analysis of gut microbiota composition between cyclists, runners, and controls showed a lower or higher abundance of fifteen different bacteria. In cyclists, there was a significant positive correlation between six bacteria, and in runners, there was a significant positive correlation between eight bacteria, with weekly training volume, time-to-exhaustion, VO2max, and blood lactate levels. This study suggests potential sport-specific characteristics in long-distance cyclists' and runners' gut microbiome signatures. These findings emphasize the differences in gut microbiota between cyclists and runners, probably due to the difference in physiological and biomechanical conditions related to the activity mode during each sport.

One-sided Cusum Chart with V-mask for Weighted Weibull Distribution Parameter Shifts

In our research, we have developed a cumulative sum control chart to identify changes in the parameter of the weighted Weibull distribution. This chart incorporates the V-mask technique and a sequential ratio test. Our analysis of the V-mask revealed that even minor shifts in the weighted Weibull distribution's parameters led to significant variations in the mask's angle, lead distance, and average run length. A change in the V-mask parameters has the following importance: it can lead to an increase in false alarms, decreased detection of true signals, change in process capability, indicates the need for process adjustments, increased security from regulatory bodies, impact on supply chain and customer relationships, and the need for re-training or re-certification. Finally, we applied the cumulative sum chart to real data from the Kabsad Scientific Hospital to illustrate the sensitivity of the proposed cumulative sum control chart. The V-mask plot showed a shift in the process mean of the dataset.

Association Among MCT1 rs1049434 Polymorphism, Athlete Status, and Physiological Parameters in Japanese Long-Distance Runners.

Monocarboxylate transporters (MCTs) comprise 14 known isoforms, with MCT1 being particularly important for lactate transport. Variations in lactate metabolism capacity and aerobic performance are associated with the T1470A polymorphism in MCT1. We aimed to investigate the frequency of the T1470A polymorphism and compare relevant physiological parameters among long-distance runners, wherein these parameters are fundamental to athletic performance. We included 158 Japanese long-distance runners (LD) and 649 individuals from the general Japanese population (CON). The frequency of the T1470A polymorphism was compared between these groups and across athletic levels using the chi-square test. Additionally, physiological data were collected from 57 long-distance runners, and respiratory gas measurements were obtained using the mixing-chamber method during a graded incremental exercise test. We observed a significant difference between the LD and CON groups in the dominant model and between the sub-28 min group and 28 min or above group in the recessive model. As the competitive level increased, the frequency of the AA genotype also increased. When comparing physiological parameters between the AA genotype and T allele, subjects with the AA genotype showed significantly higher values for oxygen uptake at lactate threshold (p = 0.001), oxygen uptake at onset of blood lactate accumulation (p = 0.01), maximal oxygen uptake (p = 0.005), and maximal blood lactate concentration (p = 0.038). These results suggest that the AA genotype of the T1470A polymorphism of MCT1 is an effective genotype associated with athletic status and aerobic capacity in Japanese long-distance runners.

7 days of L-citrulline supplementation does not improve running performance in the heat whilst in a hypohydrated state.

7days L-citrulline supplementation has been reported to improve blood pressure, O2 kinetics, gastrointestinal (GI) perfusion and endurance cycling performance through increasing arterial blood flow. In situations where blood volume is compromised (e.g., hyperthermia/hypohydration), L-citrulline may improve thermoregulation and exercise performance by redistributing blood flow to aid heat loss and/or muscle function. This study assessed 7days L-citrulline supplementation on running performance in the heat, whilst mildly hypohydrated. 13 endurance runners (2 female, 31 ± 8y, O2peak 60 ± 6mL/kg/min) participated in a randomised crossover study with 7days L-citrulline (CIT; 6g/d) or placebo (maltodextrin powder; PLA) supplementation. Participants completed a 50min running 'preload' at 65% O2peak (32°C, 50% relative humidity) to induce hyperthermia and hypohydration before a 3km running time trial (TT). Body mass and blood samples were collected at baseline, pre-preload, post-preload and post-TT, whilst core and skin temperature, heart rate and perceptual responses were collected periodically throughout. TT performance was not different between trials (CIT 865 ± 142s; PLA 892 ± 154s; P = 0.437). Core and skin temperature and heart rate (P ≥ 0.270), hydration (sweat rate, plasma volume, osmolality) indices (P ≥ 0.216), GI damage (P ≥ 0.260) and perceptual responses (P ≥ 0.610) were not different between trials during the preload and TT. 7days of L-citrulline supplementation had no effect on 3km running performance in the heat or any effects on thermoregulation or GI damage in trained runners in a hypohydrated state.

Cardiorespiratory, Metabolic, and Perceptual Responses to Blood Flow Restricted Running in Female Distance Runners.

Cardiorespiratory, Metabolic, and Perceptual Responses to Blood Flow Restricted Running in Female Distance Runners.