 PHYSICAL DEMANDS |  ENERGY EXPENDITURE |  MACRO/MICRO NUTRIENTS |
|---|---|---|
 SUPPLEMENTS |  RACE DAY PLAN |
Ultra endurance running is defined as a distance longer than a marathon ( 26.2 miles). Traditionally ultra races are 31.2 miles, 50 miles, 100 miles, or 200 miles completed with little to no rest. Races and many long training runs are more than 5 hours, therefore proper training, individualized nutrition plans, and adequate equipment are the keys for success. Throughout endurance race there are rapid changes in elevation, temperature, and humidity. Proper hydration can be the the highest concern for athletes to successful finish extreme events.
Other ultra endurance events include cycling, mountain biking, swimming, paddling and other outdoor sports. They have become more popular in the last ten years and nutrition considerations are similar across all sports. Exercise physiologists are continuing to study bioenergetics for extreme events. There is a strong division in research between a high carbohydrate diet and a high fat diet due to the fact that ultra endurance athletes use fat as their primary source of energy during the extremely long events.
NUTRITION FOR ENDURANCE SPORTS
Physical Demands
Ultra-endurance and endurance athletes need to be properly training and prepare for extreme events and conditions. Racers often drop out due too dehydration, hyponatremia, hypothermia, and gastrointestinal issues.
Dehydration
Dehydrations occurs when athletes lose more than 2% of their body weight during exercise. For more information visit the "Nutrition for Events in HEAT"
Hyponatremia
Exercise- associated hyponatremia occurs when fluids and electrolytes are out of balance while exercising. The longer the event the athletes are at more risk. Symptoms include drinking excessive amounts of water, confusion, nausea, or exhaustion. Athletes can avoid hyponatremia by monitoring water and electrolyte intake, monitor weather conditions, and pre-calculating average sweat loss.
Hypothermia
Endurance events are becoming more extreme to present new challenges of athletes. Specifically cold water ultra-events have reported illness and death from cold water temperatures. During triathlons core body temperature can continue to drop after the swim stage of the race. Race at high altitude can also cause rapid drops in temperature and humidity. Hypothermia accounts for 68.9% of rescue of mountain athletes. Athlete education and preperation is the best way to prevent hypothermia. Athletes need to understand the sign of cold illness and have an emergency plan.
GI disturbances
Gastrointestinal issues are common in endurance sports due physical stress from the activity and blood moving towards the muscle and skin for thermoregulation. Athletes need to practice intake of different foods to personalizing nutrition to prevent GI disorders. Complex carbohydrates are common causes of GI distress. Regular intake of glucose ( 5-12g/kg bw/day) with a reduction of fermentable oligosacchardise, disaccharide, and monosaccharides reduces the incidences of GI problems lowers. Some athletes ate a gluten-free diet to reduce inflammation, but research is not clear on the benefits. Athletes should not try new foods days before the competition or the day of the competition.
(Martínez-Sanz et al., 2020)
Energy Expenditure
Low intensity exercise converts free fatty acids into energy through Oxidative Phosphorylation. The primary substrate during the beginning of an is glucose via the aerobic glycolytic system. Approximately 50-60% of energy in the first 1-4 hours while athletes are competing at 70% of maximal oxygen capacity is from carbohydrates. During long events, a large amount of energy comes from free fatty acids. The more trained an athlete is the better they utilize free fatty acids for energy versus glycogen stores. When the intensity rapidly increases for 10 minutes or less or when athletes are doing a steep ascent and their oxygen uptake increases ATP is produced rapidly from glycogen stores (“Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance,” 2009).
Free fatty acids are the most efficient substrate during oxidative phosphorylation and endurance events. One gram of fat contains nine kcal of energy and one gram of carbohydrates only provides four kcal of energy. Even though Carbohydrates are more readily usable energy sources, fats are metabolized more efficiently during oxidative phosphorylation. Carbohydrates are metabolized into glucose-6 phosphate to glycolysis and it undergoes oxidative decarboxylation. Acetyl CoA then enters the Kreb cycle for higher ATP production. If an athlete's VO2 is too high athletes will reach the lactate threshold and will not be able to continue the event because their oxygen uptake is too high and glycogen stores are depleted. For an athlete to continue for many hours, Pyruvate is converted by Carbon Dioxide to NAD+ NADH+ to form Acetyl CoA during Beta oxidation. The fatty acids activate Acetyl CoA or undergo Lipogenesis to activate Acetyl CoA to enter the Krebs cycle. Oxidative phosphorylation is the longer process to produce ATP for energy but it is the most efficient and produces the highest amount of ATP per Kreb Cycle (Powers & Howley, 2017).
When endurance athletes are planning their dietary intake before an event they need to prepare for the high amount of fuel and energy use during the event. Fats are the primary fuel for an athlete in low-intensity exercise, but carbohydrates intake improves performance due to quick energy replenishment during the event and to prevent depletion of fat and protein stores which can cause muscle breakdown during the event and recovery periods. Although protein stores are utilized more for energy in events longer than 5 hours, it only contributes 5-10% at the end of the event if the athlete is consistently refueling with carbohydrates and fats (Powers & Howley, 2017).
Click on the video below for more information of the Krebs cycle and the Oxidative phosphorylation system:
(Tutorials, 2013b)
Supplementation
Caffeine
Caffeine is found in energy drinks, pre-workout beverages, teas, and coffee. Caffeine is the most common ergogenic aid besides carbohydrates before and during endurance events. In general caffeine increases the perception of time to fatigue and increases the release of adrenaline into the blood. For endurance athletes it can influence glycogen resynthesis or spar muscle glycogen resynthesis. Ergogenic effects have been measured when athletes take 3-6 mg per kg of body weight before or during exercise.Too much caffeine ( >6mg/kg of body weight) can cause anxiety, higher heart rates, headaches, GI discomfort, irritability, insomnia, and increased urine output (Tan et al., 2021).
In Lara et al. (2020) researchers measured the effects of caffeine on women throughout their menstrual cycle. The results showed an increase in peak aerobic cycling power in all three phases of the menstrual cycle. This may be a good supplement for women during their luteal phase when women are more fatigued. For women athletes moderate doses of caffeine increases muscle strength and improves performance cycling (Lara et al., 2020).
Beetroot Juices
Nitrates, including beetroot juices have many ergogenic effects for athletes when they are using the anaerobic system, but recent studies have shown performance improvements for endurance athletes. A study by Garnacho-castano et al. (2018) studied 12 male triathletes who were divided into two groups for a double-blind study. One group ingested 70 ml of beetroot juice and the other group drank a placebo. The study done on acute benefits showed no improvement on performance measures for the males during a cycling test (Garnacho-Castaño et al., 2018). In 2022 study, athletes took 3g of citrulline and 3g of beetroot juice for nine weeks. Compared to the placebo group the well-trained triathlete increased their maximal and endurance strength and improved aerobic power. More research needs to be completed using female participants (Burgos et al., 2022).
Macronutrients and Micronutrients
It is recommended by Powers & Howley, (2017):
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Increase the athlete's carbohydrate intake to 10g/kg of body weight one day before an ultra endurance event to elevate the glycogen store in the muscle.
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Athlete’s should consume the recommended protein and fat during normal training leading up to an event.
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The morning of an event athletes should eat a well balanced breakfast with slightly higher carbohydrates, fats and protein three hours before the start of the event.
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One hour before the event athletes should include only 1-4g/kg of body weight of high glycemic carbohydrates with an equal ratio of glucose and fructose. This can prevent hypoglycemia by sparing liver stores during the beginning of the event.
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If athletes are taking in a mix of glucose and fructose they must continue to replenish every 30 minutes during a long event to completely restore the glycogen levels every one to three hours.
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With such a long event athletes will also need to replenish their fat stores for satiation and long term energy supply, but it is harder on the stomach to digest fats during an event. The better trained the athlete the easier it is for them to digest and metabolize fat without GI issues (Powers, 2017).
Week Before an Event
Nutrition is adjusted the days leading up to the race to prepare for the event. Carbo-loading is an effective way to increases carbohydrate (CHO) stores before the event. It is recommended that endurance athletes increase their carbohydrates by 10-12g of CHO kg of body weight per day. Many women eat less than their daily energy expenditure and may need to increase their calories and carbohydrates even more to influence carbohydrate stores. The morning of the race athletes should eat a breakfast containing proteins, fats, high fiber carbohydrates and water with high osmolality. If athletes eat at least one hour prior to the race they might avoid gastrointestinal disruptions (Bentley et al., 2008).
During the Event
During long distance events, athletes should consume 1.0-1.1g or carbohydrates per min or 60g-80g of carbohydrates per hour. Depending on the intensity of the event athletes may need to increase to 1.5g per min. Fluid intake varies on the climate conditions of the event, the size of the athletes and the amount they perspire. During training athletes should monitor their fluid intake and their weight. If any athlete loses more than 2% of their body weight during a training session or event they can be dehydrated. When athletes are dehydrated they may have imbalances in their electrolytes or risk an unhealthy rise in body temperature. If athletes intake too much water they risk development of hyponatremia (Bentley et al., 2008).
After Event
After a 5 hour or longer event athletes need to replenish their carbohydrates within 24 hours. Powers recommends 500-700g of carbohydrates for energy, muscle recovery and rebuild. The post event meal within four hour of the event should include 1.2g/kg of carbs and 1.2-1.4g of protein for muscle repair (Powers,2017).
The athlete should be maintaining her weight during peak training to maintain lean mass while training at high volumes. If the athlete desires to lose weight they should be encouraged to lose weight before their high volume preparation phases of training (Antonio et al., 2014). Meeting energy expenditure calorie needs can be difficult for many women, due to preparation and stigma around eating higher volumes of food. Eating several meals per day comprised of carbohydrates, fats and proteins can help women maintain a steady energy intake and eat enough calories to match their total expenditure (Jeukendrop & Gleeson, 2018).
