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MULTI-DAY EVENTS
 VEGAN ATHLETES |  PREPARATION |  ENERGY EXPENDITURE |
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 ENVIROMENTAL CONSIDERATION |  OXIDATIVE STRESS |  NUTRITION |
Outdoor Recreation creates unique physical demands due to rapid environmental changes and high daily energy expenditure. Outdoor multi-day events are typically self-sustained athletes who are biking, running, adventure racing, or multi-sport events. Some events allow for a racing crew that assists the athlete in restocking supplies. When preparing for a prolonged event athletes need to pack enough nutrition and hydration to match energy intake with energy expenditure. Properly educating athletes on energy expenditure, physical demands, and environmental conditions reduces emergency rescues and improve overall athletic performance.
Energy Expenditure
Low intensity exercise converts free fatty acids into energy through Oxidative Phosphorylation. The primary substrate during the beginning of an exercise bout 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 the oxidation of free fatty acids. The more trained an athlete is the better they utilize free fatty acids for energy versus glycogen stores.
For more information on Oxidative Phosphorylation click the link below:
Preparation
Many multi-day events are self-sufficient, which refers to athletes needing to carry all of their items and cannot restock until check-points or public facilities to purchase items. There are theories but not sound research that athletes that carry more items and heavy packs are more prone to injury, slower hikes, and other adverse events. Athletes need to determine what to pack to remain safe from the elements, but keep their gear lightweight for long days of carrying the packs. In a large study with over 900 participants, the most essential gear was hydration, food, clothes/layer, and rain gear (Daniel et al., 2021).
This is a list of other essential items for hikers to pack to be well prepared for their long event:
List of essential items to prevent emergency evacuation:
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Fire
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First-aid supplies
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Hydration
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Illumination
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Insulation
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Navigation
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Nutrition
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Shelter
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Sun protection
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Tools
Multi-day and ultra-endurance athletes need to be properly trained and preplan for extreme events and conditions to remain safe and healthy while on the trails. Researchers reported an increase in mountain rescues as long events evolve to become more extreme. Martinez-Sanz et al. (2020) reviewed 33 articles that examined adverse outcomes during multi-day ultra-endurance events. Racers often discontinued the events due to dehydration, hyponatremia, hypothermia, and gastrointestinal issues (Martinez-Sanz et al., 2020).
Proper hydration and maintaining a healthy core temperature should be the primary goal for athletes during preparation and to remain on the trail. When athletes lose more than 2% of their body weight they are at risk for severe illness. Water intake needs to be in conjunction with electrolyte intake. If athletes over drink water and their sodium levels become too low they can suffer from hyponatremia. Hyponatremia is very rare except during extremely long events. 15-30% of athletes reported incidences of hyponatremia in ultra-endurance races and it is also reported during triathlons, mountain biking, and long open-water swimming events. The symptoms of dehydration and hyponatremia are similar: confusion, exhaustion, muscle cramping, and GI symptoms. Monitoring water, electrolyte, urine color, and urine quantity can help athletes self-diagnose and remain safe while they are on the trail (Martinez-Sanz et al., 2020). For more information click the buttons below:
Environmental Considerations
Maintaining Core Body Temperature
Hyperthermia is when an athlete's body temperature is above 101 degrees due to metabolic heat and/or high environmental temperatures with high humidity levels. When the body can no longer self-regulate heat exhaustion and heat stroke occurs when the body's temperature is between 103-104 degrees. Symptoms of hyperthermia are decreased sweating response, irritability, confusion, conventions, and alterations of consciousness. Athletes should acclimatize to the heat 7-10 days before an event and dress in performance layers with sun protection (Martinez-Sanz et al., 2020). For more information on heat related illness click the button:
Hypothermia is when the body temperature drops and athletes can no longer maintain a healthy core body temperature. Hypothermia can cause heart arrhythmia which was the reported cause of death during rescues. This is most commonly reported in long open-water swim events and mountaineering expeditions. When athletes are competing in cold temperatures they need to have many layers to interchange to avoid sweating but remain warm. Athletes need to also consider keeping their fluids and foods from freezing. Most importantly athletes need to have an emergency action plan if they are not prepared for rapid changes in the environment (Martinez-Sanz et al., 2020).
Environmental Considerations
Oxidative Stress
Does hiking improve cellular aging and reduce stress?
Low-to-moderate endurance exercise is known to release psychological stress and many hiker reports having a spiritual experience while they are isolated in nature. Gagnon et al.(2019) measured changes in fifteen multi-day canoeing athletes' physiological adaptions which affect oxidative stress. A few studies have shown increases in oxidative stress after a single-day event, but chronic training demonstrates increases in antioxidant activity. Oxidative stress was measured by changes in malondialdehyde (MDA), superoxidase dismutase, and relative telomere length. Total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), Triglycerides (TG), serum glucose, creatinine levels, electrolytes, serum total testosterone, plasma insulin levels, cortisol levels, and urea were measured before and after the fourteen-day event. The only measures that had significant reductions were triglycerides, serum glucose, and creatinine levels. Superoxoidase dismutase activity was greater after the multi-day hike. Researchers conclude this may show that low-level chronic activity may increase anti-oxidant activity which positively influences cellular aging (Gagnon et al., 2019).
Nutrition Recommendations
For the health of the athlete, the most important nutrition recommendation is to maintain their body weight during the event through the appropriate energy intake to match high amounts of energy expenditure. Athletes should aim to get most of their energy intake through nutrient-dense foods. It is easier to digest carbohydrates when exercising because carbohydrates rapidly produce energy. The week before an event athletes can increase their carbohydrates to ensure that glycogen stores are complete. There was no specific recommendation for multi-day athletes, but endurance athletes were recommended to increase their carbohydrates by 10-12g/kg of body weight per day, 3-5 days before the event ( Vitale et al., 2019)
Nutrition recommendations are under-researched for stage races, hiking, and other multi-day events. Outdoor, multi-day event athletes will need to make individualized fuel plans factoring in the recommendations for endurance athletes.
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Hydration and calorie intake may need to increase with rapid climate changes, changes in intensity, or altitude and elevation increases.
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On average low-intensity athletes should consume 1.0-1.1g of carbohydrates per minute or 60-90g of carbohydrates per hour.
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Daily protein and fat recommendations should be close to average daily intake on a training day.
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Protein recommendations for endurance athletes are 1.6-2.0g/kg of body weight per day. Fat should be between 20-30% of athletes' total daily intake.
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While participating in a long event athletes should divide protein and fat intake throughout the day as long as their digestive system tolerates the slower digesting foods. An athlete can also eat higher protein items before sleep to allow time for digestion ( Jeukendrup & Gleeson, 2018).
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Hydration :
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Athletes may find it easier to consume liquid calories. Powders are less weight to carry in their packs.
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Hydration recommendations for athletes are: drink 400-800mL per hour of water of beverages with carbohydrates and electrolytes. Hydration plans need to be individualized based on body size, sweat rate, and exercise efforts.
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Athletes should practice hydration in different climates before an event.
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If athletes weigh themselves before an exercise bout and then immediately post-event, they can measure how much weight they lost during the exercise bout.
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For every pound, an athlete loses they should drink about 1L of water to replenish water loss. On average, the athletes will lose 300-600 mg/h if the athletes' sweat rate is high. This is approximately 1.2L of water/h. Athletes' nutrition should include sodium, potassium, and other minerals to replenish losses through sweat and exercise ( Vitale et al., 2019).
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Special Considerations for Vegan Athletes
There is not much research on recommendations for vegan ultra-endurance athletes. Wirnitzer & Kornexl (2014) reported a case study of a vegan ultra-athletes. Her nutrition was reported during a 8-day stage mountain bike race. The female athlete weighed 49.6kg and her height was 161cm. She trained 25 hours a week to prepare for the Transalp Challenge. This case study was her second successful finish in the top 20 female racers while being a vegan athlete. Her weight remained stable, indicating the proper amount of fuel and water intake during the event. The athletes hourly carbohydrate intake was 1.2g/kg/hr or 92g/hr; the current recommendations for prolonged stage races was 10-13 g/kg/day. The athletes carbohydrate intake was almost double the current recommendations. The table shows her nutrition intake for the event (Wirnitzer & Kornexl, 2014):
