Ultra-endurance Events Research Articles

Psychophysiological, Body Composition, Biomechanical and Autonomic Modulation Analysis Procedures in an Ultraendurance Mountain Race.

The current research aimed to analyze psychophysiological, body composition, biomechanical and autonomic modifications in an ultraendurance mountain race. We analyzed 11 finisher voluntary athletes that participated in a 51.2km ultraendurance mountain race. We measured before and after the mountain ultraendurance event the following parameters: Rate of perceived exertion, body composition, cortical arousal, blood pressure, body temperature, forced vital capacity, blood oxygen saturation, isometric hand strength and heart rate variability parameters. The results of temperature, rate of perceived exertion, heart rate and the percentage of body water at the end of the race increased significantly. However, the variables of body weight, body fat, muscle, body mass index, abdominal fat, blood oxygen saturation, systolic and diastolic blood pressure, cortical arousal and hands and legs strength significantly decreased after the race. The square root of the average of the sum of the differences squared between normal adjacent R-R intervals, percentage of differences between normal adjacent R-R intervals, high-frequency, sensitivity of the short-term variability, and long-term variability decreased significantly after the race. By contrary low-frequency increased significantly at the end of the race. An ultraendurance mountain event produced a large anticipatory anxiety response, an increase in sympathetic modulation, body fat consumption, percentage of body water, and RPE, not affecting the cortical arousal.

The Global Model of Pacing Process for Long and Ultra-Long Distance

Pacing process can be thought as a complex process in which the subject controls the intensity of exercise at any time. It is a key factor determining performance, notably in ultra-endurance events. We agree with the fact that perceived exertion is central in the process of pacing as proposed in the central governor model and the psycho-motivational model, notably. But we claim that using effort, as a unique parameter, is not sufficient and that motivation should be integrated in a more complete manner. The aim of this paper was to explore the role of effort but also other perceptive parameters and motivation in fatigue regulation and pacing process. The impact of motivation and feelings were also envisaged in order to propose a novel model of pacing adapted to ultra-endurance. We explore the manner in which objective and subjective characteristics of the task but also the factors of motivation, emotional state, the level of acceptation of emotional state and physiological state interact which each other in order that the athlete self-selects his intensity during fatiguing exercise. Finally, we propose a new “global model of pacing process” (GMPP) based on the self-determination theory, the theory of goal setting and task motivation, and the theory of energy conservation, in order to have a more holistic view of this complex process.

Age and Performance from 10 Seconds to a 6-Days Race

Purpose: An increasing amount of people are turning to new challenges such as the completion of an ultra-marathon and choose to continue to train intensively despite advanced age. As a result, numerous epidemiological data are available and constitute an experimental model for the research community that studies the effects of aging on physiological functions. The objective of the study is to measure the relationships between age and performance over the entire athletic spectrum from 100 m up to the 6-day ultra-marathon event for men and women. Method: The Top 50 male and female ages and race speed races of all time were compiled with 12 events ranging from 100 m to 6-day races (N=1200). A second database made up of record race-speeds by age (N=1682) was created for all 12 events and for both genders. Results: For both genders, a very significant increase (p<0.01) in age for the Top 50 based on race distance is noticeable from the 100 m sprint to the 6-day race, with an even higher climb starting at the marathon. On the other hand, the age range also increases with the running distance for both genders. The area under the curve (AUC) decreases significantly (p<0.01) with the race distance for both genders. Conclusion: This study measured the impact of aging on the world's best performances ranging from sprints to ultra-endurance events in a context where peak-age performance increases with the distance of the event for both genders.

Team diversity enhances performance under extreme conditions: Why are mixed-gender teams a winning combination?

Background: Diversity as an equity-driven proposition is self-evident. Diversity as a performance enhancer is less obvious, though it has been shown to improve team performance and resilience in work settings, including genuine commercial advantage from increasing the number of women in key decision-making roles due to the subtle differences in decision making and influences on the group. Anecdotal evidence exist of competitive advantage that team diversity affords in extreme sports such as adventure racing – an ultra-endurance event where teams of four compete over a cross-country course using a combination of multiple disciplines. Massive cash prizes create incentives to squeeze all possible performance gains from each team member. Combined with extreme physical challenges of the course, this makes for an intuitive prediction that the competition should be dominated by all-male teams. Yet the records show the opposite: (1) most elite adventure racing teams around the world have included females; (2) the premier category in international adventure racing events is the mixed-gender category; (3) mixed gender teams have dominated the Word Championship podiums since 2001.

Maximal Fat Oxidation is Related to Performance in an Ironman Triathlon.

The aim of the present study was to investigate the relationship between maximal fat oxidation rate (MFO) measured during a progressive exercise test on a cycle ergometer and ultra-endurance performance. 61 male ironman athletes (age: 35±1 yrs. [23-47 yrs.], with a BMI of 23.6±0.3 kg/m2 [20.0-30.1 kg/m2], a body fat percentage of 16.7±0.7% [8.4-30.7%] and a VO2peak of 58.7±0.7 ml/min/kg [43.9-72.5 ml/min/kg] SEM [Range]) were tested in the laboratory between 25 and 4 days prior to the ultra-endurance event, 2016 Ironman Copenhagen. Simple bivariate analyses revealed significant negative correlations between race time and MFO (r2=0.12, p<0.005) and VO2peak (r2=0.45, p<0.0001) and a positive correlation between race time and body fat percentage (r2=0.27, p<0.0001). MFO and VO2peak were not correlated. When the significant variables from the bivariate regression analyses were entered into the multiple regression models, VO2peak and MFO together explained 50% of the variation observed in race time among the 61 Ironman athletes (adj R2=0.50, p<0.001). These results suggests that maximal fat oxidation rate exert an independent influence on ultra-endurance performance (>9 h). Furthermore, we demonstrate that 50% of the variation in Ironman triathlon race time can be explained by peak oxygen uptake and maximal fat oxidation.

Chronic probiotic supplementation with or without glutamine does not influence the eHsp72 response to a multi-day ultra-endurance exercise event.

Probiotic and glutamine supplementation increases tissue Hsp72, but their influence on extracellular Hsp72 (eHsp72) has not been investigated. The aim of this study was to investigate the effect of chronic probiotic supplementation, with or without glutamine, on eHsp72 concentration before and after an ultramarathon. Thirty-two participants were split into 3 independent groups, where they ingested probiotic capsules (PRO; n = 11), probiotic + glutamine powder (PGLn; n = 10), or no supplementation (CON; n = 11), over a 12-week period prior to commencement of the Marathon des Sables (MDS). eHsp72 concentration in the plasma was measured at baseline, 7 days pre-race, 6-8 h post-race, and 7 days post-race. The MDS increased eHsp72 concentrations by 124% (F[1,3] = 22.716, p < 0.001), but there was no difference in the response between groups. Additionally, PRO or PGLn supplementation did not modify pre- or post-MDS eHsp72 concentrations compared with CON (p > 0.05). In conclusion, the MDS caused a substantial increase in eHsp72 concentration, indicating high levels of systemic stress. However, chronic PRO or PGLn supplementation did not affect eHsp72 compared with control pre- or post-MDS. Given the role of eHsp72 in immune activation, the commercially available supplements used in this study are unlikely to influence this cascade.

Performance and Energy Balance during a 439 Mile Endurance Run

Running for extreme distances or time has become increasingly popular, however, energy balance and its effect on performance is of great concern. PURPOSE: This case study examined the physical performance and energy balance in a 51 year old firefighter completing an 11-day, 439 mile solo run across Texas. METHODS: All food and drink consumed during the 11 day run were recorded to assess energy intake during the run. Energy expenditure and exercise data were recorded via a heart rate/GPS monitor during each run. Nude body weight was recorded each morning. RESULTS: Daily, the subject completed 39.98±2.61 miles (range 33.26-42.98 mi) in 11.2±1.2 hrs (range 9.74-12.97 hrs) at a 16.8±1.3 min/mi pace (range 15.17-18.45 min/mi). Subject consumed 4398±811 kcals per day (range 3280-5617 kcals/day) and expended 3804±271 kcals per run (range 3280-5617 kcals/run). Over the 11 days, the subject lost 2.6 kg of body weight. Total energy expenditure (5397 ± 271 kcal) was greater than energy intake (4398 ± 812 kcal; p=0.005). Over the 11 days, there was a trend towards a slower mile pace (r=0.832, p=0.001). Heart rate was also lower across the 11 days (range: 95 - 137 bpm; p=0.045). There was no change in core body temperature throughout each run (p=0.125 Time x Day interaction) or across the 11 days (p=0.078). On average, capillary lactate levels increased from 2.3 ± 1.3 mmol/L to 6.5 ± 2.3 mmol/L pre to post run (p=0.005). CONCLUSION: Energy balance is important for sustaining the high training and performance levels required for ultra-endurance events. However, the athlete was not able to consume enough calories to remain in energy balance. Nutritional needs assessments during training and competition should be an integral part of the preparation for participation in an ultra-endurance event. Supported by Valdosta State University Faculty Research Seed Grant

Energy, macronutrient and water intake during a mountain ultramarathon event: The influence of distance

ABSTRACTAdequate dietary strategies are essential for the successful participation in ultra-endurance races. The aim of this study was to evaluate and compare the energy and water intakes of participants during three different mountain ultra-endurance runs. The study took place at the “Ultra Mallorca Serra de Tramuntana” (Mallorca, Spain), an ultra-endurance mountain event with runners participating either in a 44-km (Marathon, n = 51), a 67-km (Trail, n = 109) or a 112-km (Ultra, n = 53) run competition. Participants in the study answered a questionnaire focused on the nutritional intake within an hour after finishing the competition. Mean energy intake during the competitions was 183 kcal · h¯1, with an average carbohydrate intake of 31 g · h¯1 (52.1% of participants consumed less than 30 g · h¯1). No significant differences between competitions were found in these parameters. However, a higher percentage of energy from lipids in participants in the Trail and the Ultra was found (P = 0.034). Furthermore, significant differences were observed in water intake per hour of competition (P = 0.039), with the lowest value for the intake during the Ultra competition. In conclusion, the majority of the participants in the study present low carbohydrate intakes. However, fluid intake seems to be adequate. Different distances did not significantly influence the participants’ nutritional strategies.

The Effects of a 36-Hour Mixed Task Ultraendurance Race on Mucosal Immunity Markers and Pulmonary Function

The present study was conducted to assess the changes in mucosal immunity and pulmonary function among participants in a 36-hour mixed task ultraendurance race. Thirteen of the 20 race participants volunteered for the investigation (age 34±5 y). The event consisted of a mixture of aerobic, strong man, and military-style exercise. Participants had a pulmonary function test and gave a finger stick capillary blood sample and unstimulated saliva samples both before the event and upon dropout or completion. The blood sample was analyzed for hematocrit, and the saliva sample was analyzed for salivary flow rate, salivary alpha amylase, salivary immunoglobulin A (IgA), and IgA type 1. Significant differences were noted among the finishers and those who dropped out in salivary flow rate (P = .026), salivary IgA (P = .017), and peak expiratory flow (P = .05) measurements. Salivary flow rate and IgA for the race finishers were reduced from pre- to postrace, whereas the nonfinishers showed no change or small increases. No significant differences emerged for other variables. Based on the results of the present investigation, finishing a 36-hour mixed task ultra-endurance event results in a decline in both pulmonary function and mucosal immunity compared with competitors who do not finish.

Low-Carbohydrate-High-Fat Diet: Can it Help Exercise Performance?

Low-carbohydrate-high-fat (LCHF) diets have been used as a means of weight loss and control of symptoms in several clinical conditions. There is emerging evidence that the metabolic changes induced by LCHF diets enhance endurance performance. The aims of this review are to examine the evidence of LCHF diets in improving various aspects of athletic performance. Long-term LCHF dietary intake may help control body weight and fat mass while maintaining lean body mass in athletes in weight-sensitive sports. LCHF-adapted endurance athletes can reach the maximal fat oxidation rate of approximately 1.5 g/min, with a lower carbohydrate oxidation rate and similar muscle glycogen content and a resynthesis rate compared to their counterparts consuming high-carbohydrate-low-fat (HCLF) diets. The elevated fat oxidation rate and glycogen sparing effect may improve performance in ultra-endurance events. These metabolic changes may also prevent the decline in performance in later stages of repeated high-intensity movements, in which the aerobic metabolism becomes more important. However, elevated blood concentrations of non-esterified fatty acids and ammonia during exercise after LCHF diets may lead to early development of central fatigue. It appears that at least several months of adaptation to a LCHF diet are required for the metabolic changes and restoration of muscle glycogen to occur. Further investigations on LCHF diets are needed regarding (1) performance after weight loss in weight-categorized sports; (2) repeated high-intensity exercise performance; (3) development of central fatigue during endurance events; (4) perceptual-motor performance during prolonged intermittent sports; and (5) ideal dietary fatty acid compositions.

Metabolic Responses to the Yukon Arctic Ultra: Longest and Coldest in the World.

PurposeThe Yukon Arctic Ultra is considered the longest and coldest ultraendurance event in the world. Cold exposure and exercise has been reported to influence circulating levels of myokines, adipokines, and hepatokines that may influence considerable alterations in the regulation of metabolism. The purpose of the study was to evaluate the influence of the Yukon Arctic Ultra (430-mile event) on potential activators of brown fat, metabolites, and body composition in healthy individuals.MethodsEight male and female participants (mean ± SEM: age, 44 ± 3 yr; body mass index, 23.4 ± 0.9) were recruited for participation. Blood samples were collected at pre-event, mid-event, and post-event checkpoints.ResultsThe temperature during the event ranged from −45°C to −8°C. Because of these extremely challenging conditions, 50% of the participants withdrew from competition by the 300-mile mark, and those that surpassed 300 miles lost a significant (P = 0.002; P = 0.01) amount of body weight (76 ± 5 kg to 73 ± 4 kg) and fat mass (13 ± 1 kg to 12 ± 3 kg), respectively. With respect to serum irisin, there was a trend (P = 0.06) toward significance from pre-event (1033 ± 88 ng·mL−1), mid-event (1265 ± 23 ng·mL−1) to post-event (1289 ± 24 ng·mL−1). Serum meteorin-like and fibroblast growth factor-21 remained stable throughout the event. There were no changes in creatinine, acetoacetate, acetate, and valine. Serum lactate decreased (P = 0.04) during the event.ConclusionsThe influence of cold exposure and extreme physical exertion may promote substantial increases in serum irisin, and specific alterations in substrate metabolism that largely preserve skeletal muscle and physiological resilience.

Use of Non-Steroidal Anti-Inflammatory Drugs among Participants in a Mountain Ultramarathon Event

The aim of this study was to evaluate and compare the prevalence of non-steroidal anti-inflammatory drugs (NSAID) consumption immediately before, during and immediately after three mountain ultra-endurance runs that differed in their course distance. This observational study took place at the Ultra Mallorca Serra de Tramuntana (Mallorca, Spain), an ultra-endurance mountain event with runners participating either in a 112-km (Ultra, n = 58), a 67-km (Trail, n = 118) or a 44-km (Marathon, n = 62) run competition. Participants in the study answered, within an hour after finishing the competition, a questionnaire focused mainly on NSAIDs consumption. Among study participants, 48.3% reported taking NSAIDs at least for one of the time-points considered: before, during and/or immediately after the competition, with more positive responses (having taken medication) found for the Ultra (60.3%) than for the Trail (49.2%) and the Marathon (35.5%). Among consumers, the Ultra participants reported the lowest intake before and the highest during the race, while participants in the Marathon reported similar consumption levels before and during the race. In conclusion, a high prevalence of NSAID consumption was found among athletes participating in an ultra-endurance mountain event. Competition duration seemed to determine both the prevalence and the chronological pattern of NSAID consumption.

Substance use and misuse in a mountain ultramarathon: new insight into ultrarunners population?

ABSTRACTEndurance and ultra-endurance events have become increasingly popular. The aim of our study was to explore the use of medication among endurance runners participating in the 2014 Infernal Trail des Vosges. Among the 389 runners engaged, 297 (76.3%) completed a specific questionnaire dealing with substance use/misuse. Our results show a 27% (before the race) and 18% (during the race) prevalence of substance use. The two major classes of substances used were non-steroidal anti-inflammatory drugs (NSAIDs; 9.8%) and painkillers (6.7%), principally because of osteo-articular pain (29.6%) or to prevent pain (28.2%). A positive correlation was found between substance consumption before (past month) and during the race (overall medication: p < 0.0001; NSAIDs: p = 0.008). Our results could be explained by the specific characteristics of ultrarunners predominantly motivated by personal achievement and general health (recreational approach). However, education interventions should further be delivered regarding the risks of substance use in ultra-endurance events.

Association Between Energy Balance and Metabolic Hormone Suppression During Ultraendurance Exercise.

Ultraendurance athletes often accumulate an energy deficit when engaging in ultraendurance exercise, and on completion of the exercise, they exhibit endocrine changes that are reminiscent of starvation. However, it remains unclear whether these endocrine changes are a result of the exercise per se or secondary to the energy deficit and, more important, whether these changes can be attenuated by increased dietary intake. The goal of the study was to assess the relationship between changes in key metabolic hormones after ultraendurance exercise and measures of energy balance. Metabolic hormones, as well as energy intake and expenditure, were assessed in 14 well-trained male cyclists who completed a 1230-km ultraendurance cycling event. After completion of the event, serum testosterone (-67% ± 18%), insulin-like growth factor-1 (IGF-1) (-45% ± 8%), and leptin (-79% ± 9%) were significantly suppressed (P < .001) and remained suppressed after a 12-h recovery period (P < .001). Changes in IGF-1 were positively correlated with energy balance over the course of the event (r = .65, P = .037), which ranged from an 11,859-kcal deficit to a 3593-kcal surplus. The marked suppression of testosterone, IGF-1, and leptin after ultraendurance exercise is comparable to changes occurring during acute starvation. The suppression of IGF-1, but not that of other metabolic hormones, was strongly associated with the magnitude of the energy deficit, indicating that athletes who attained a greater energy deficit exhibited a more pronounced drop in IGF-1. Future studies are needed to determine whether increased dietary intake can attenuate the endocrine response to ultraendurance exercise.

Short-term heat acclimation prior to a multi-day desert ultra-marathon improves physiological and psychological responses without compromising immune status

ABSTRACTMultistage, ultra-endurance events in hot, humid conditions necessitate thermal adaptation, often achieved through short term heat acclimation (STHA), to improve performance by reducing thermoregulatory strain and perceptions of heat stress. This study investigated the physiological, perceptual and immunological responses to STHA prior to the Marathon des Sables. Eight athletes (age 42 ± 4 years and body mass 81.9 ± 15.0 kg) completed 4 days of controlled hyperthermia STHA (60 min·day‒1, 45°C and 30% relative humidity). Pre, during and post sessions, physiological and perceptual measures were recorded. Immunological measures were recorded pre-post sessions 1 and 4. STHA improved thermal comfort (P = 0.02), sensation (P = 0.03) and perceived exertion (P = 0.04). A dissociated relationship between perceptual fatigue and Tre was evident after STHA, with reductions in perceived Physical (P = 0.04) and General (P = 0.04) fatigue. Exercising Tre and HR did not change (P > 0.05) however, sweat rate increased 14% (P = 0.02). No changes were found in white blood cell counts or content (P > 0.05). Four days of STHA facilitates effective perceptual adaptations, without compromising immune status prior to an ultra-endurance race in heat stress. A greater physiological strain is required to confer optimal physiological adaptations.

The influence of race length on arterial compliance following an ultra-endurance marathon

There is inconclusive evidence concerning the effects of routine participation in ultra-endurance events on cardiovascular disease (CVD) risk. Arterial compliance is a reliable, non-invasive, and effective tool for evaluating CVD risk. The purpose of this research was to examine if race length influences acute changes in arterial compliance following an ultra-marathon event. A total of 46 ultra-marathon runners were recruited including 21 participants (39.8 ± 8.3 years, 6 females) in the 80-km event and 25 participants (43.7 ± 9.8 years, 3 female) in the 195-km event. Arterial compliance was measured via radial applanation tonometry (CR-2000, HDI) for diastolic pulse contour analysis before and following the race. Significant between-group differences were found for changes in large arterial compliance with a decrease (increase in stiffness) following the 195-km event and an increase following the 80-kilometre event (p < .05). Longer race lengths are associated with greater reductions in large arterial compliance following recreational ultra-marathon running. Assessment of arterial compliance might be a useful prognostic tool to assess the long-term risk of CVD among ultra-marathon runners.

Effects of two neuromuscular training programs on running biomechanics with load carriage: a study protocol for a randomised controlled trial.

BackgroundIn recent years, athletes have ventured into ultra-endurance and adventure racing events, which tests their ability to race, navigate, and survive. These events often require race participants to carry some form of load, to bear equipment for navigation and survival purposes. Previous studies have reported specific alterations in biomechanics when running with load which potentially influence running performance and injury risk. We hypothesize that a biomechanically informed neuromuscular training program would optimize running mechanics during load carriage to a greater extent than a generic strength training program.MethodsThis will be a two group, parallel randomized controlled trial design, with single assessor blinding. Thirty healthy runners will be recruited to participate in a six weeks neuromuscular training program. Participants will be randomized into either a generic training group, or a biomechanically informed training group. Primary outcomes include self-determined running velocity with a 20 % body weight load, jump power, hopping leg stiffness, knee extensor and triceps-surae strength. Secondary outcomes include running kinetics and kinematics. Assessments will occur at baseline and post-training.DiscussionTo our knowledge, no training programs are available that specifically targets a runner’s ability to carry load while running. This will provide sport scientists and coaches with a foundation to base their exercise prescription on.Trial registrationANZCTR (ACTRN12616000023459) (14 Jan 2016)Electronic supplementary materialThe online version of this article (doi:10.1186/s12891-016-1271-9) contains supplementary material, which is available to authorized users.

Effects of Training for a 439 Mile Endurance Run on Performance and Energy Balance

Running for extreme distances or time has become increasingly popular, however, little is known about the training process needed to successfully complete an ultra-endurance event. PURPOSE: This case study examined 28 weeks of training on physical performance, training volume, and energy balance in a 51 year old firefighter preparing for an 11-day, 439 mile solo run across Texas. METHODS: A maximal treadmill exercise test and body fat assessment via plethysmography was conducted at baseline and 28 weeks later. Nutritional intake was recorded biweekly via food diary. Exercise training data were recorded via a heart rate/GPS monitor for all workouts. Resting heart rate and morning body weight was self-reported weekly. Training consisted of running, tire dragging, and stair repeats in the fire station. RESULTS: VO2max improved by 5.19% (52.0 vs 54.2 ml/kg/min; 4.17 vs 4.38 L/min (4.94%)), while percent body fat increased 2.54% (23.6 vs 24.2%) following 28 weeks of training. Subject consumed 13731±2578 kcals per week (~1962 kcals/day) and expended 2658±1518 kcals per week (~380 kcals/day) from exercise. At the end of training, the subject had lost 2.17 kg from baseline weight, however weight fluctuated throughout the 28 weeks (77.63-82.54 kg). There was no correlation between weekly weight change from baseline and calories consumed (r=0.264, p=0.384) or weekly exercise caloric expenditure (r=0.385, p=0.748). CONCLUSION: Twenty-eight weeks of training resulted in improved maximal aerobic capacity in this 51 year old ultra-endurance athlete. Energy balance is important for sustaining the high training levels required for ultra-endurance events. However, the athlete was not able to consume enough calories to remain in energy balance. Nutritional needs assessments during training and competition should be an integral part of the preparation for participation in an ultra-endurance event. Supported by Valdosta State University Faculty Research Seed Grant

Core Temperature In Triathletes During The Ironman World Championship - Kailua Kona (Hawaii)

During ultra-endurance events, thermoregulation plays an important role in guaranteeing physical performance and avoiding health problems (i.e: heat stroke). Hyperthermia occurs when the core temperature rises above 38.5°C. Weather conditions (heat & humidity) or training level of athletes may affect thermoregulation. PURPOSE: To measure core temperature (Tcore) in high-level triathletes during the Ironman World Championship (Hawaii) under thermal stress conditions. METHOD: Tcore of fifteen triathletes (age: 36.11±7.36 years, weight: 71.14±7.12 kg, height: 179± 0.04 cm, fat %: 8.48±0.85) who classified for the Ironman World Championship in Kailua - Kona were measured using an ingestible pill telemetry system before competition, upon completion of the event (marathon) and after 60 minutes of recovery. Event mean ambient temperature was 29.1 °C (range 20–36 °C) and relative humidity was 76% (range 71-88%). Body Mass Index (BMI) and exercise perceived exertion (Borg Scale and Visual Analog Scale-Pain) were measured before the event and 60 minutes after the event. Performance variables were extracted from their own GPS and official race time and splits. Statistical analysis was performed using Repeated Measured Test, ANOVA. RESULTS: Finish time (hh:mm:ss) was 10:06:56 ± 0:48:30. Initial Tcore was 36.62 ± 0.17 °C, increasing at the end of the event (38.55 ± 0.64 p<0.01) and remaining high 60 minutes after the event (38.65 ± 0.41°C p<0.002). BMI significantly decreased after the event (22.85 ± 1.11 vs. 21.73 ±1.36 p<0.05) while exercise perceived exertion - Borg Scale (10.2 ± 1.64 vs. 18.60 ± 1.67 P<0.003) and perceived muscle pain - VAS Pain (2.75± 1.59 vs. 9.08 ± 1.13 p<0.001) increased significantly after the event. CONCLUSION: High-level triathletes competing under thermal stress conditions in the Kona Ironman reached a state of hyperthermia during the event. After 60 minutes of recovery, when exercise perceived exertion was at a maximum, the hyperthermic state persisted. Strategies to aid cooling and recovery, especially after the race, should be considered by both triathletes and event organizers. Supported by Government of Extremadura-Spain (GR15020 - CTS036) and 226ERS- Endurance Research Lab

Muscle damage, physiological changes, and energy balance in ultra-endurance mountain-event athletes.

The biological response to ultra-endurance mountain race events is not yet well understood. The aim of this study was to determine the biochemical and physiological changes after performing an ultra-endurance mountain race in runners. We recruited 11 amateur runners (age: 29.7 ± 10.2 years; height: 179.7 ± 5.4 cm; body mass: 76.7 ± 10.3 kg). Muscle damage, lactate concentration, energy balance, rating of perceived exertion (RPE), heart rate (HR), heart rate variability (HRV), body composition changes, and jump performance were analyzed before, during (only lactate, HR, and HRV), and after the race. Athletes completed 54 km in 6 h, 44 min (±28 min). After the race, myoglobin and creatine kinase concentration increased from 14.9 ± 5.2 to 1419.9 ± 1292.1 μg/L and from 820.0 ± 2087.3 to 2421.1 ± 2336.2 UI/L, respectively (p < 0.01). In addition, lactate dehydrogenase and troponin I significantly increased after the race (p < 0.01). Leukocyte and platelet count increased by 180.6% ± 68.9% and 23.7% ± 11.2%, respectively (p < 0.001). Moreover, after the competition, athletes presented a 3704 kcal negative energy balance; a significant increase in RPE values; a decrease in countermovement and squat jump height; and a decrease in body mass and lower limb girths. During the event, lactate concentration did not change and subjects presented a mean HR of 158.8 ± 17.7 beats/min, a significant decrement in vagal modulation, and a significant increase in sympathetic modulation. Despite the relative "low" intensity achieved, ultra-endurance mountain race is a stressful stimulus that produces a high level of muscle damage in the athletes. These findings may help coaches to design specific training programs that may improve nutritional intake strategies and prevent muscle damage.