Ultra-endurance Events Research Articles

Body Mass Changes and Fluid Consumption During an 80.5-km Treadmill Time Trial

Fluid consumption and maintenance of body mass is crucial to exercise performance, particularly during ultraendurance events. The current study aimed to assess body mass change and hydration status during an 80.5-km treadmill time trial (TT). Ultrarunners were recruited to complete 80.5 km on a motorized treadmill within an artificial laboratory environment. Body mass (BM) was determined prior to, at 16.1-km intervals, and on completion of an 80.5-km TT using bioelectrical impedance analysis (BIA). Ad libitum fluid intake was permitted during the trial, and total fluid consumption and gastrointestinal (GI) symptoms were noted throughout. Total fluid intake was 3294.4 ± 1402.9 mL with an average consumption of 386.9 ± 212.2 mL/h. Prerunning BM (72.59 ± 8.48 kg) was reduced throughout the TT. Overall exercise-induced BM loss averaged 2.78 ± 0.94 kg with a 4.01 ± 1.35% decrease over time, although some retention of BM occurred in the latter stages of the TT. Ambient conditions were maintained throughout with no significant fluctuations in temperature (20.8° ± 0.2°C; P > .05) or humidity (35.7 ± 1.3%; P > .05). Average time to completion was 7 hours 28 minutes 9 seconds ± 1 hour 25 minutes 12 seconds at an average speed of 10.8 ± 1.5 km/h. The current study indicates that participants were unable to maintain prerunning BM following the completion of an 80.5-km TT with an average BM loss of 4%. Consensus guidelines state to avoid BM losses of >3%; therefore this emphasizes the importance of optimal hydration strategies in ultraendurance running.

Energy Cost of Running During a Bout of 80.5-km Treadmill Running

Success in ultraendurance running is composed of many interrelated variables. Notably the involvement of the cardiovascular system has been proposed to explain variance in performance. At present, there is limited data on the changes in the energy cost of running (Cr) during bouts of ultraendurance running. Therefore, the purpose of this study was to identify changes and adjustments in Cr and respiratory variables over an 80.5-km treadmill time trial (TT). Participants were instructed to complete 80.5 km on a motorized treadmill and to cover the distance in the fastest possible time. Respiratory variables ( QUOTE o2 [oxygen consumption], QUOTE co2 [carbon dioxide production], and RER [respiratory exchange ratio]) were measured via indirect calorimetry every 16.1 km at a set speed of 8 km/h. Running speed and heart rate were continually monitored throughout the 80.5-km TT. Average run time to completion was 7 hours 28 minutes 9 seconds ± 1 hour 25 minutes 12 seconds at a mean speed of 10.8 ± 1.5 km/h (pace, 5:34 ± 1:04 min/km). QUOTE o2 increased by 21.8% from the start of the TT to completion (31.19 ± 2.89 vs 38.0 ± 6.41 mL∙min–1∙kg–1, respectively), while RER decreased from the start to 32.2 km whereupon RER plateaued. There was a significant increase of 24.2% in Cr (P < .001) from the start to completion of the TT. The current study indicated adjustments in QUOTE o2, Cr, and substrate utilization during an 80.5-km treadmill TT. Results indicated a shift to fatty acid oxidation as a main fuel source over a bout of 80.5 km, which corresponded with the increase in Cr. These findings may influence pacing strategies and overall success of performance in ultraendurance events.

Pacing in a self-paced world record attempt in 24-h road cycling.

BackgroundPacing strategy plays a major role in sport performance. However, there is a dearth of knowledge concerning pacing during ultra-endurance sport events. The present case study investigated the pacing of an ultra-cyclist in a self-paced attempt to break the world record in 24-h road cycling and, with all the caveats and the limitations affecting a case report, could be useful in generating hypotheses and further studies about pacing dynamics during prolonged sport performances.Case descriptionA well experienced ultra-cyclist completed laps of 11.731 km during 24 h and the support crew recorded for each lap time and power output in Watt. The trend in cycling speed and power output across laps was investigated using regression analyses. A mixed-effects regression model including lap, ambient air temperature, air pressure, air humidity and wind speed as fixed variables was used to investigate a relationship of environmental factors with cycling speed.Discussion and evaluationThe athlete achieved 896.173 km within the 24 h. He set a new world record by breaking the old record (Jure Robic, 2004, 834.77 km) by 61.403 km. He cycled at an average speed of 37.34 km/h with an average power output of 250.2 W. The decrease in cycling speed and power output across laps could be modelled linearly. Temperature and wind speed were related to cycling speed during the whole event. There was a significant interaction air temperature × relative humidity for the whole event.ConclusionsThe athlete adopted a positive pacing (i.e. speed gradually declined throughout the event) and environmental factors (i.e. temperature and wind speed) influenced cycling speed during the event.

Ultra-Marathon Athletes at Risk for the Female Athlete Triad.

BackgroundWorldwide female participation in ultra-endurance events may place them at risk for the female athlete triad (FAT). The study objectives were to establish triad knowledge, occurrence of disordered eating and triad risk amongst participants of the 2014 89-km Comrades Marathon event.MethodsA survey utilising the Low Energy Availability in Females questionnaire (LEAF-Q) and Female Athlete Screening Tool (FAST) questionnaire was conducted on female participants in order to determine the risk. In addition, seven questions pertaining to the triad were asked in order to determine the athlete’s knowledge of the triad. Athletes were requested to complete the anonymous questionnaire after written informed consent was obtained while waiting in the event registration queues. Statistical analyses included Pearson product–moment correlations, chi-square tests and cross-tabulations to evaluate associations of interest.ResultsKnowledge of the triad was poor with 92.5 % of participants having not heard of the triad before and most of those who had, gained their knowledge from school or university. Only three athletes were able to name all 3 components of the triad. Amenorrhoea was the most commonly recalled component while five participants were able to name the component of low bone mineral density. Of the 306 athletes included in the study, 44.1 % were found to be at risk for the female athlete triad. One-third of participants demonstrated disordered eating behaviours with nearly half reporting restrictive eating behaviours. There is a significant association between athletes at risk for the triad according to the LEAF-Q and those with disordered eating (χ2(1) = 8.411, p = 0.014) but no association (or interaction) between triad knowledge and category (at risk/not at risk) of LEAF-Q score (χ2(1) = 0.004, p = 0.949). More athletes in the groups with clinical and sub-clinical eating disorders are at risk for the triad than expected under the null hypothesis for no association.ConclusionsOnly 7.5 % of the female Comrades Marathon runners knew about the triad despite 44.1 % being at a high risk for the triad. Therefore, education and regular screening programmes targeting these athletes are overdue. Postmenopausal athletes are at particularly high risk for large losses in bone mass if they experience chronic energy deficiency and hence require special focus.

Hematological and metabolic changes after a 6-day ultramarathon on indoor cycle and treadmill

Ultra-endurance events may induce biological changes as a consequence of intense muscle stress and hormonal fluctuations. Two ultra-endurance athletes, one on treadmill, the other on a home trainer pinion, have attempted to break world records for greatest distance covered over 6 days in Paris on January 4–10, 2015 (“six extreme days”). We analyzed the hematological, hormonal and biochemical changes. Hematological, biochemical, hormonologic, metabolic and specific to oxidative stress analysis were conducted on fresh and frozen blood samples collected a week before (D-7), 30 minutes (D6) and 2 days (D8) after the event for both sportsmen. Periods of waking/sleep, cardiovascular data (pulse, saturation) and developed efforts (distance, speed) were monitored throughout the event. Hemoglobin, hematocrit and iron parameters (serum iron, ferritin, transferrin saturation coefficient) were found lower on D6, after 2750 km cycling or 713 km running, than on D-7 (hemoglobin decreased from 15.2 g/dl before the event to 13.3 g/dl just after). They start to increase back on D-8. Leukocytes (6.5 to 9.4 G/l between D-7 and D-6), haptoglobin (tripled between D-7 and D-8, from 1 to 3 g/l), liver enzymes, Creatine Phosphokinase, troponin, Brain Natriuretic Peptide and uric acid rose during the event before going back down on D8 without however reaching back initial levels. The observed transient anemia is multifactorial, inflammatory, iron deficiency but without here any element for hemolysis. Hepatic cytolysis and heart stress are commonly encountered [1] . No study however focuses on oxidative stress enzymes (glutathione, lipid peroxidation products, activation of xanthine oxidase) after such a long effort, for which mobilization of leukocytes and increased uric acid (antioxidant) are indirect markers [2] . Data from this exploration should help enhancing our understanding of the impact of very prolonged effort on the oxidative stress chain, and paves the way for potential improvement in the training methods of athletes.

The acute testosterone, growth hormone, cortisol and interleukin-6 response to 164-km road cycling in a hot environment

This study investigated the acute endocrine responses to a 164-km road cycling event in a hot environment. Thirty-four male experienced cyclists (49.1 ± 8.3 years, 86.8 ± 12.5 kg, 178.1 ± 5.1 cm) participating in a 164-km road cycling event were recruited. Blood samples were collected within 0.3–2.0 h before the start (PRE: ~0500–0700 h) and immediately following the ride (POST). Samples were analysed for testosterone, growth hormone (GH), cortisol and interleukin-6 (IL-6). The temperature and humidity during the event were 35.3 ± 4.9°C and 47.2 ± 14.0%, respectively. Based on the finishing time, results for the fastest (FAST, 305 ± 10 min) and the slowest (SLOW, 467 ± 31 min) quartiles were compared. At POST, testosterone concentration was significantly (P < 0.05) lower (PRE, 20.8 ± 8.6; POST, 18.2 ± 6.7 nmol · L−1), while GH (PRE, 0.3 ± 0.1; POST, 2.3 ± 0.3 µg · L−1), cortisol (PRE, 661 ± 165; POST, 1073 ± 260 nmol · L−1) and IL-6 (PRE, 4.0 ± 3.4; POST, 22.4 ± 15.2 pg · mL−1) concentrations were significantly higher than those at PRE. At POST, GH and cortisol were significantly higher for the FAST group than for the SLOW group (GH, 3.6 ± 2.0 and 1.0 ± 0.8 µg · L−1; cortisol, 1187 ± 209 and 867 ± 215 nmol · L−1). Participation in an ultra-endurance road cycling event in a hot environment induced significant acute changes in concentrations of circulating hormones, with a greater augmentation of GH and cortisol in those completing the ride fastest.

Sport participation and Ramadan observance: Advice for the athlete

Introduction: A growing number of Muslim athletes now engage in international competition. This raises the question of the advice they should be given if a major event occurs during the month of Ramadan. Methods: A narrative review has been based upon books and extensive reviews completed by the author and other investigators. Results: Practical considerations hamper assessment of the effects of Ramadan upon physical performance, but there seem small decreases in muscular strength and both anaerobic and aerobic capacity. Nevertheless, athletes who wish to observe Ramadan can reduce such effects by prior adjustment of diet and training plans, minimizing sleep loss, and careful management of fluid and food intake during the period of intermittent fasting. Conclusion: Competitors in most events can observe Ramadan with a small loss of athletic performance. However, intermittent fasting can endanger health for individuals with type I diabetes mellitus, and for participants in ultra-endurance events (particularly under hot conditions).

The role of fluid temperature and form on endurance performance in the heat.

Exercising in the heat often results in an excessive increase in body core temperature, which can be detrimental to health and endurance performance. Research in recent years has shifted toward the optimum temperature at which drinks should be ingested. The ingestion of cold drinks can reduce body core temperature before exercise but less so during exercise. Temperature of drinks does not seem to have an effect on the rate of gastric emptying and intestinal absorption. Manipulating the specific heat capacity of a solution can further induce a greater heat sink. Ingestion of ice slurry exploits the additional energy required to convert the solution from ice to water (enthalpy of fusion). Body core temperature is occasionally observed to be higher at the point of exhaustion with the ingestion of ice slurry. There is growing evidence to suggest that ingesting ice slurry is an effective and practical strategy to prevent excessive rise of body core temperature and improve endurance performance. This information is especially important when only a fixed amount of fluid is allowed to be carried, often seen in some ultra-endurance events and military operations. Future studies should evaluate the efficacy of ice slurry in various exercise and environmental conditions.

The Influence of Training Status on Vascular Stiffness Following an Ultra-Endurance Event

The Influence of Training Status on Vascular Stiffness Following an Ultra-Endurance Event

Creatine Kinase Elevations in Ultra-endurance Runners at Altitude

Introduction: Creatine kinase (CK) is a sensitive enzyme marker for muscle damage in athletes. Elevated CK levels have been reported in many endurance physical activities. The consequence and possible long-term sequela of the CK elevation in these athletes is unknown. There is a paucity of literature stating actual numerical values of CK associated with competing in an ultra-endurance event with extreme environmental conditions. PURPOSE: To assess the CK levels of athletes pre- and post- the Leadville 100 race at high elevation (2800-3800m). METHODS: We collected blood samples from voluntary athletes, 65 runners (79% male) before and 84 (81% male) runners immediately after a 161-km ultramarathon in Leadville, Colorado in August 2014. CK and sodium levels were analyzed from the samples obtained. IRB approval was received prior to all data collection. RESULTS: Out of 672 athletes who started the race, 351 successfully completed the race in less than 30 hours (52%). The majority of starters and finishers were male (∼85%). We were able to collect both pre- and post-race blood samples from 37 runners. Out of 84 runners who we collected blood samples after the race, 19 were not able to successfully finish the race.Out of these 37 runners, the mean pre-race CK (PrCK) was 124±64 U/L. The mean post-race CK (PoCK ) was 14569±14729 U/L. There was a linear correlation between lower sodium levels and higher CK levels post-race (p=0.003; r2=0.10). There was no statistically significant correlations between post-race CK levels and athletes’ BMI, age, or finishing time. Based on the electronic survey conducted 1-2 weeks after the race (92% response rate), none of the athletes who we collected blood samples on visited an emergency department or a physician’s office after the race. CONCLUSION: Significant elevation of CK level occurs as a result of running ultramarathons with lower sodium levels significantly correlated with higher CK levels. The majority of athletes with significantly elevated CK levels were asymptomatic and required no major medical attention. Further studies are needed to better equip the medical team in monitoring and treating ultra-endurance athletes. This study was in part funded by the ACSM Clinical Sports Medicine Endowment Grant.

Ultraendurance Cycling in a Hot Environment

The purpose of this field investigation was to identify and clarify factors that may be used by strength and conditioning professionals to help athletes drink adequately but not excessively during endurance exercise. A universal method to accomplish this goal does not exist because the components of water balance (i.e., sweat rate, fluid consumed) are different for each athlete and endurance events differ greatly. Twenty-six male cyclists (mean ± SD; age, 41 ± 8 years; height, 177 ± 7 cm; body mass, 81.85 ± 8.95 kg) completed a summer 164-km road cycling event in 7.0 ± 2.1 hours (range, 4.5-10.4 hours). Thirst ratings, fluid consumed, indices of hydration status, and body water balance (ingested fluid volume - [urine excreted + sweat loss]) were the primary outcome variables. Measurements were taken before the event, at designated aid stations on the course (52, 97, and 136 km), and at the finish line. Body water balance during exercise was not significantly correlated with exercise time on the course, height, body mass, or body mass index. Thirst ratings were not significantly correlated with any variable. We also observed a wide range of total sweat losses (4.9-12.7 L) and total fluid intakes (2.1-10.5 L) during this ultraendurance event. Therefore, we recommend that strength and conditioning professionals develop an individualized drinking plan for each athlete, by calculating sweat rate (milliliter per hour) on the basis of body mass change (in kilograms), during field simulations of competition.

Hydration status affects mood state and pain sensation during ultra-endurance cycling

Laboratory-based studies indicate mild dehydration adversely affects mood. Although ultra-endurance events often result in mild to moderate dehydration, little research has evaluated whether the relationship between hydration status and mood state also exists in these arduous events. Therefore, the purpose of this study was to evaluate how hydration status affected mood state and perceptual measures during a 161 km ultra-endurance cycling event. One hundred and nineteen cyclists (103 males, 16 females; age = 46 ± 9 years; height = 175.4 ± 17.9 cm; mass = 82.8 ± 16.3 kg) from the 2011 and 2013 Hotter’N Hell events participated. Perceived exertion, Thermal, Thirst, and Pain sensations, Brunel Profile of Mood States, and urine specific gravity (USG) were measured pre- (~1 h before), mid- (~97 km), and post-ride. Participants were classified at each time point as dehydrated (USG ≥ 1.022) or euhydrated (USG ≤ 1.018). Independent of time point, dehydrated participants (USG = 1.027 ± 0.004) had decreased Vigour and increased Fatigue, Pain, Thirst, and Thermal sensations compared to euhydrated participants (USG = 1.012 ± 0.004; all P < 0.01). USG significantly correlated with Fatigue (r = 0.36), Vigour (r = −0.27), Thirst (r = 0.15), and Pain (r = 0.22; all P < 0.05). In conclusion, dehydrated participants had greater Fatigue and Pain than euhydrated participants. These findings indicate dehydration may adversely affect mood state and perceptual ratings during ultra-endurance cycling.

Occult bleeding, haematochezia and the endurance athlete: what are the risks?

Objective. To examine the risks of visceral ischaemia associated with participation in endurance sport, including gastro-intestinal bleeding and systemic endotoxaemia. Methods. A systematic search of the Ovid/Medline data-base from January 1996 to May 2015, combining the terms ischaemia/visceral ischaemia/gastro-intestinal haemorrhage/bleeding/ and endotoxins with exercise/endurance exercise/physical endurance/marathon/ultra-marathon/triathlon, supplemented by a review of reference lists and personal files. Results. Around 20% of participants in marathons and other endurance events develop objective manifestations of visceral ischaemia in the first 2 days following a race, usually occult gastro-intestinal bleeding. A small proportion of athnletes develop overt bleeding. This generally resolves over a few days, although there are 2 reported cases that required a partial colectomy, and 1 reported death. In some individuals, plasma levels of bacterial endotoxins may also rise. Conclusions. Once other more dangerous diagnoses have been excluded, the blood loss associated with exercise-induced visceral ischaemia can usually be treated expectantly. A watch must be kept for anaemia secondary to repeated blood loss, but the risks of bleeding requiring colectomy and bacterial sepsis seem too small either to require other specific treatment or to influence clinical advice on the wisdom of participating in ultra-endurance events.

Energy balance of triathletes during an ultra-endurance event.

The nutritional strategy during an ultra-endurance triathlon (UET) is one of the main concerns of athletes competing in such events. The purpose of this study is to provide a proper characterization of the energy and fluid intake during real competition in male triathletes during a complete UET and to estimate the energy expenditure (EE) and the fluid balance through the race. Methods: Eleven triathletes performed a UET. All food and drinks ingested during the race were weighed and recorded in order to assess the energy intake (EI) during the race. The EE was estimated from heart rate (HR) recordings during the race, using the individual HR-oxygen uptake (Vo2) regressions developed from three incremental tests on the 50-m swimming pool, cycle ergometer, and running treadmill. Additionally, body mass (BM), total body water (TBW) and intracellular (ICW) and extracellular water (ECW) were assessed before and after the race using a multifrequency bioimpedance device (BIA). Results: Mean competition time and HR was 755 ± 69 min and 137 ± 6 beats/min, respectively. Mean EI was 3643 ± 1219 kcal and the estimated EE was 11,009 ± 664 kcal. Consequently, athletes showed an energy deficit of 7365 ± 1286 kcal (66.9% ± 11.7%). BM decreased significantly after the race and significant losses of TBW were found. Such losses were more related to a reduction of extracellular fluids than intracellular fluids. Conclusions: Our results confirm the high energy demands of UET races, which are not compensated by nutrient and fluid intake, resulting in a large energy deficit.

Assessing hydration status during ultra-endurance events: Are certain assessment techniques promoting fluid-overload?

Assessing hydration status during ultra-endurance events: Are certain assessment techniques promoting fluid-overload?

Validation of a 24 h recall questionnaire culturally modified for use in rural south Indian populations

Validation of a 24 h recall questionnaire culturally modified for use in rural south Indian populations

Psychophysiological response and energy balance during a 14-h ultraendurance mountain running event.

Many studies have researched the psychophysiological response and energy balance of athletes in numerous ultraendurance probes, but none has investigated an ultraendurance mountain running event. The current study aims to analyze changes in blood lactate concentration, rating of perceived exertion, heart rate, heart rate variability, and energy balance after the performance of an ultraendurance mountain running event. The parameters in the 6 participants who finished the event were analyzed (age, 30.8 ± 3.1 years; height, 176.2 ± 8.6 cm; body mass, 69.2 ± 3.7 kg). The race covered 54 km, with 6441 m of altitude change, 3556 m downhill and 2885 m uphill. The athletes completed together the race in 14 h and 6 min. After the ultraendurance event, the athletes presented a negative energy balance of 4732 kcal, a blood lactate concentration of 2.8 ± 0.3 mmol/L, a heart rate mean/heart rate maximum ratio of 0.64, a heart rate mean of 111.4 ± 5.9 beats/min, a decrease in vagal modulation, and an increase in sympathetic modulation, and recorded 19.5 ± 1.5 points on the 6-20 rating of perceived exertion scale. The event was a stressful stimulus for the athletes despite the low intensity measured by blood lactate concentration and heart rate. The results obtained may be used by coaches as a reference parameter of heart rate, heart rate variability, rating of perceived exertion, and lactate concentration to develop specific training programs. In addition, the energy balance data obtained in this research may improve nutritional intake strategies.

Physiopathological, Epidemiological, Clinical and Therapeutic Aspects of Exercise-Associated Hyponatremia.

Exercise-associated hyponatremia (EAH) is dilutional hyponatremia, a variant of inappropriate antidiuretic hormone secretion (SIADH), characterized by a plasma concentration of sodium lower than 135 mEq/L. The prevalence of EAH is common in endurance (<6 hours) and ultra-endurance events (>6 hours in duration), in which both athletes and medical providers need to be aware of risk factors, symptom presentation, and management. The development of EAH is a combination of excessive water intake, inadequate suppression of the secretion of the antidiuretic hormone (ADH) (due to non osmotic stimuli), long race duration, and very high or very low ambient temperatures. Additional risk factors include female gender, slower race times, and use of nonsteroidal anti-inflammatory drugs. Signs and symptoms of EAH include nausea, vomiting, confusion, headache and seizures; it may result in severe clinical conditions associated with pulmonary and cerebral edema, respiratory failure and death. A rapid diagnosis and appropriate treatment with a hypertonic saline solution is essential in the severe form to ensure a positive outcome.

Managing collapsed or seriously ill participants of ultra-endurance events in remote environments.

Increasing participation in ultramarathons and other ultra-endurance events amplifies the potential for serious medical issues during and immediately following these competitions. Since these events are often located in remote settings where access may be extremely limited; the diagnostic capabilities, treatment options, and expectations of medical care may differ from those of urban events. This work outlines a process for assessment and treatment of athletes presenting for medical attention in remote environments, with a focus on potentially serious conditions such as major trauma, acute coronary syndrome, exertional heat stroke, hypothermia, hypoglycemia, exercise-associated hyponatremic encephalopathy, severe dehydration, altitude illness, envenomation, anaphylaxis, and bronchospasm. A list of suggested medical supplies is provided and discussed. But, given that diagnostic and treatment options may be extremely limited in remote settings, it is important for medical providers to understand how to assess and manage the most common serious medical issues with limited resources, and to be prepared to make presumptive diagnoses when necessary.

Providing Sport Psychology Support to an Athlete in a Unique, Ultra-Endurance Event

Participation in ultra-endurance events has increased in popularity in recent years. Many of these ultra-endurance events have used sport and exercise theory as an interventional tool to quantify the impact of the challenge. However, some challenges are unique, and include feats of incredible endurance in order to push the human body to its maximal limit. We describe a case study of a sport psychologist providing support to an athlete prior to, during and following the completion of a challenge that involved walking the same mile, 1,000 consecutive times during 1,000 consecutive hours, thereby lasting 42 days. We also review and detail the experiences gained from a sport psychology perspective with the intention of sharing the applied experience amongst other sport psychologists and the wider community.