This year, she spent more than 30 consecutive hours running and walking up and down a Mount Isa hill, until finally she reached the equivalent elevation of Mount Everest's peak — a giant 8, metres.
After completing the mammoth task, Ms Whitehead said the only thing she was worried about was what she would come up with next. Like Ms Lynch, she said after the km and 30 hours, she just "did it". We acknowledge Aboriginal and Torres Strait Islander peoples as the First Australians and Traditional Custodians of the lands where we live, learn, and work.
The science. Posted 18 Jul 18 Jul Thu 18 Jul at am. Why ultra-runners thrive in continuing to push the distance. Ultramarathon runner shows women how to go the distance later in life. The women running and winning ultramarathons. More on:. Socceroos' homecoming dampened by injury to star defender Harry Souttar.
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Prime Minister says he does not believe he has told a lie in public life. Live: Victorians on alert for severe weather as heavy rain and high winds forecast to batter the state. Regular training results in an increase in the thickness of the muscle forming the heart wall, in particular, the left side of the heart. This is the side of the heart responsible for circulating oxygenated blood around the body and to the muscles during exercise.
Increased thickness of the left ventricle wall the lower chamber of the heart , enables endurance athletes to pump more blood out of their heart each time it beats. A regular adult, exercising at their maximum level, can have a stroke volume of ml. However, because of the increased thickness of the heart wall, endurance athletes have a stroke volume during maximal exercise of around ml. The amount of blood the heart pumps in one minute is called cardiac output.
In elite endurance runners, it can be nearly twice that of an average adult during maximal exercise. Getting enough oxygen to the working muscles is also vital. Activities lasting longer than a couple of minutes mainly rely on aerobic metabolism the process by which we use oxygen to turn fuel, such as fats and sugars, into energy , making a constant supply of oxygen crucial to success.
Elite marathon runners can breathe around litres of air per minute during maximal exercise. This combined ability of the lungs and heart to take in and transport oxygen means that elite athletes have a very high VO2 max — the maximum amount of oxygen the body can use in a minute. Of note, few human studies exist regarding green tea extract on athletic performance.
In a review documenting later studies in humans, green tea has not shown a similar performance enhancement [ 63 ], and the few studies that did suggest improvements were only in untrained sedentary populations.
Therefore, it remains to be seen if green tea catechins exert a significant performance effect on trained and non-overweight athletes. Additionally, a final word of warning bears consideration: since the methods of growing, harvesting, and preparing green tea vary widely and any supplement may contain contaminants or banned substances , athletes should exercise caution. When selecting green tea, green tea extract, or any other supplement, the authors advocate to choose wisely from trusted sources e.
Caffeine, a popular supplement in the general population, has been heavily researched in sports for its ergogenic effects. Caffeine is a trimethylxanthine, similar to adenosine in chemical structure [ 71 ]. It has numerous proposed mechanisms of action. Peripherally, caffeine increases motor unit recruitment [ 73 ] and helps mobilize calcium to increase muscle contraction [ 72 ]. Systemically, caffeine assists in mobilization of fatty acids for energy decreasing dependence on glycogen and increases thermogenesis [ 72 ].
This dosing can improve sustained maximal endurance e. Of additional practical importance is the synergistic effect of caffeine when consumed with carbohydrate. Taking the two together improves cycling work production compared to caffeine or carbohydrate alone, while perception of work remains unchanged [ 74 ].
Of note in one study, the anhydrous form of supplemental caffeine may have a greater ergogenic effect than drinking coffee [ 75 ], although in this study the caffeine capsule was actually taken with water. Therefore, the authors question if practically this ultimately may be similar to drinking coffee.
Athletes may also be concerned about severe or systemic side effects with this level of dosing. A recent review proposes that caffeine does not result in more serious complications such as water-electrolyte imbalances, dehydration, hyperthermia, or reduced exercise-heat tolerance [ 78 ]. Traditionally, there has been a long-held paradigm that habitual caffeine intake may blunt the ergogenic effects of acute pre-exercise caffeine consumption.
Both caffeine groups had faster time-trial completion compared to placebo, and the moderate dose group had improved performance to a greater extent than the low dose group [ 82 ]. The authors recommend that athletes begin at lower doses if they are not caffeine tolerant and adjust accordingly. Some athletes find it useful to cycle caffeine with periods of abstaining from coffee during lower intensity training or prior to races, then resuming coffee at race time or during high intensity training.
With daily caffeine intake, the performance benefit begins to decline at about 15—18 days and may disappear by 4 weeks. Periodic topping-up during prolonged exercise authors suggest every 1—2 h as needed may also be of benefit. Most commonly Lactobacillus and Bifidobacteria are the primary species used [ 83 ] and produce lactic acid from carbohydrates to provide the sour taste in fermented foods. Probiotics have many proposed health benefits including antimicrobial activity to improve diarrheal illness and reduce urogenital infection, assisting with lactose intolerance, preventing constipation, improving immune function, and possibly even having anticarcinogenic effects to the colon [ 83 ].
Endurance athletes are susceptible to upper respiratory infection URI , and elite athletes have a higher rate of URI than recreational athletes [ 84 ].
Probiotics may play a role in reducing these symptoms [ 85 ]. The field of probiotic research in athletes is still in its early stages, and few studies exist regarding performance outcomes [ 86 ]. In a review of the literature, only six studies were found, and while two did show an ergogenic effect on performance, one study was in mice [ 86 ].
A recent review in healthy physically active people and athletes showed probiotics may help with reduction of GI and upper respiratory symptoms [ 85 ]. Endurance athletes when fatigued show similar clinical characteristics of patients who experience reactivation of Epstein Barr virus less T-cell secretion of interferon gamma and exhibit diminished natural killer cell activity [ 83 ].
Probiotic supplementation can improve mucosal T-cell interferon concentration to normal levels and attenuate the reduction in natural killer cell activity [ 83 ]. The probiotic strain, dose, period of consumption and form of administration however e.
These benefits may help the athlete in terms of comfort and recovery from exercise, and therefore indirectly may play a role in performance.
Endurance athletes prone to URI or GI symptoms, those susceptible to infection, or who travel frequently for events and are exposed to travel-related illness, may especially find benefit. Carbohydrate and water have the most research, but the role of post-exercise protein, caffeine, and antioxidants may have important impacts on endurance athletes.
Aggressive carbohydrate refeeding at 1. Ideally, dosing at 15—min intervals achieve the highest glycogen synthesis rates in the early first 3—5 h recovery period [ 11 ].
If the athlete can only tolerate 0. If the exercise had a significant eccentric component leading to significant muscle damage marathons, downhill running , post-exercise protein with a high leucine content — mg within the first 2 h can stimulate MPS and recovery [ 9 , 30 ]. Similarly, eccentric and highly stressful exercise bouts that raise free radical and ROS levels can delay recovery to peak form due to the excessive oxidant load surpassing the innate antioxidant system [ 58 , 59 , 60 , 61 ]; ingestion of high antioxidant foods such as tart cherry juice may improve recovery [ 62 ].
Long endurance bouts can challenge hydration status; fluid and therefore bodyweight loss is expected with exercise and 0. However, the authors caution this strategy in hypertensives or those needing to restrict total sodium intake.
Interestingly, addition of potassium does not show any additional rehydration benefit [ 11 ]. There has been considerable discussion in both the medical literature and popular media [ 88 , 89 ] regarding the recent trend of low carbohydrate diets. Nevertheless, endurance athletes may find it useful to purposefully exercise in lower carbohydrate availability states. Endurance athletes may experience this when exercising in difficult conditions, such as bad weather and low fuel availability.
Exercising in low carbohydrate states can be achieved in several ways: for example, reducing total carbohydrate intake at certain times of their training plan, training in a fasted state, performing two training sessions in close proximity without adequate refueling, or simply early morning training before breakfast [ 8 ]. The world of endurance nutrition is continually evolving, and clinicians need to keep up-to-date as research emerges on sports nutrition topics.
Furthermore, the commercial supplement industry is ever-changing. New products with purported benefits are being advertised to athletes as well as the general population, claiming improvements in performance and general health.
Elite athletes, after they maximize training adaptations, often look to gain marginal benefits that they believe may be pivotal in whether they make the podium or not. This paper therefore summarizes the latest evidence-based recommendations as well as highlights hot topics and controversial subjects in order to equip the clinician dealing with the endurance athlete with current knowledge.
Table 1 summarizes the key recommendations for macronutrients, hydration, and supplements. High carbohydrate diets have long been tested and continues to be recommended in endurance athletes. Most endurance athletes are familiar with high carbohydrate diets, but the importance of protein both total daily intake and immediate post-exercise consumption may not be as well-known by athletes. Attention to adequate intake is emphasized to improve recovery, ameliorate muscle damage, and maintain muscle mass.
There has been a shift away from forced hydration plans and personalizing fluid intake according to thirst and sweat rates to avoid exercise-associated hyponatremia. Athletes commonly take supplements, and a few supplements may have merit in the endurance world. Nitrates may help reduce oxygen cost and improve time to exhaustion, possibly cardiorespiratory performance at anaerobic threshold, and even VO 2max.
Studies are mixed however, and nitrate may preferentially benefit non-elite recreational athletes. Antioxidants may help an athlete who has already peaked in terms of training adaptation, where the main goal is facilitating recovery and earlier return to competition in multi-stage events. Caffeine has a very large body of research behind its ergogenic effects, with side effects being the main limiting factor. There is a paucity of quality research on probiotics for athletes, but chronic URI and GI symptoms common in endurance athletes may potentially be attenuated with Lactobacillus and Bifidobacteria supplementation.
Additionally, as with any supplement, since the US Food and Drug Administration FDA is not authorized to review dietary supplement products for safety and effectiveness before they are marketed, there is the risk of contaminants and illicit substances in commercial supplements. These substances may not only present a safety risk but may be on a banned substance list for professional athletes [ 92 ]. While it is recommended that athletes obtain nutrition from whole foods, we acknowledge that athletes may take supplements and recommend they choose from trusted sources.
We hope this review helps clinicians treating and counseling endurance athletes clear up misconceptions athletes may have regarding sports nutrition and provide evidence-based recommendations according to current research. In the absence of high-quality evidence, we also provide practical recommendations on select supplements and offer our clinical advice on specific topics based on years of treating endurance athletes.
Future research may help shed new light on the potential pleotropic benefits of probiotics, fats including CLA, fish oil, and MCTs, more clarity of the roles of nitrates and antioxidants, and the ideal balance of low vs. Conceptualization, methodology, software, K. National Center for Biotechnology Information , U. Journal List Nutrients v. Published online Jun 7. Author information Article notes Copyright and License information Disclaimer. Received Apr 9; Accepted Jun 6. This article has been cited by other articles in PMC.
Abstract Background: Endurance events have experienced a significant increase in growth in the new millennium and are popular activities for participation globally. Keywords: athletes, physical endurance, sports nutritional sciences, nutritional requirements, dietary supplements. Introduction Participation in endurance events has increased both nationwide and globally, with 2.
Open in a separate window. Figure 1. Results 3. Carbohydrate Carbohydrate requirements for the endurance athlete can be a fiery topic, often leading to passionate and sometimes confrontational debates on ideal intake amongst the fitness and medical community. Table 1 Key recommendations for macronutrients, hydration, and supplements exercise duration is listed in italics within parentheses. Protein Traditionally, endurance athletes have placed less of a priority on protein in comparison to carbohydrate.
Pre-, During, and Post-Exercise Protein Requirements Compared to resistance exercise, few studies have been done on pre- and during exercise protein intake with endurance activities, but available evidence shows it may improve same day and next day endurance performance [ 30 ]. Hydration Fluid intake recommendations for endurance athletes have evolved [ 38 , 39 , 40 ]. Nitrates Dietary nitrate has been used for years in medical conditions such as cardiovascular disease and hypertension [ 49 ].
Antioxidants The role of antioxidant supplements in sport was notably questioned by Gomez-Cabrera [ 58 , 59 , 60 , 61 ] who highlighted the potential blunting of the training adaptation response to exercise.
Caffeine Caffeine, a popular supplement in the general population, has been heavily researched in sports for its ergogenic effects. Concern with High Carbohydrate Diets? Discussion The world of endurance nutrition is continually evolving, and clinicians need to keep up-to-date as research emerges on sports nutrition topics. Author Contributions Conceptualization, methodology, software, K. Funding This research received no external funding. Conflicts of Interest The authors declare no conflict of interest.
References 1. Shilton A. Miller J. The Running Bubble Has Popped. Costa R. Sports Med. Nikolaidis P. Nutrition in Ultra-Endurance: State of the Art. Ebell M. Sports Nutr. Thomas D. Spriet L. Jeukendrup A. Nutritional Considerations in Triathlon. Getzin A. Noakes T.
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