OxfamTrailwalker 2007 Nutrition for Trailwalkers Dr Janice Tsang

Trailwalker is an endurance event requiring proper physical training & nutrition to sustain good performance Failure to complete trailwalkerFailure to complete trailwalker Physical injury / pain Muscle cramps / fatigue Dizziness, blackout / hypoglycemia Vomiting / dehydration

Nutrition Nutrition Integral part of training Exercise  nutrient needs 70 kg person at 6 kph on level ground cal/hr 24 hr - 8,640 cal Optimal nutrition brings out best performance Develop right eating habit during training Before, during and after Trailwalker Carbohydrate, water, protein, fat and supplements Food variety

Carbohydrate Main source of energy in exercise ( %) Carbohydrate  glucose  glycogen stored in muscles/liver  exercise   muscle tissue  calories demand Body’s carbohydrate reserve <1,200 calorie - only last 90 minutes of strenuous exercise Continuous intake - eat carbohydrate every hour along the trail Avoid hypoglycemia - poor-judgement, bad temper, dizziness and fatigue

Carbohydrate Carbohydrate loading – 10-12gm/kg/day for 5-7 days Aim:  glycogen stored in muscles & liver Practised by mature athletes in endurance events Begin with a high protein, low carbohydrate diet & exercise strenuously few days before (start of the wk) Eat a very high carbohydrate diet (pancakes, rice or noodles) and exercise very little few days towards the event, esp hrs before the event

Fluids H2O  digest & metabolise food H2O  sweat to lower body temperature Well hydrated - 8 glasses 1 day before 500 mls 2 hr before  clear 500 mls 15 min before  urine Sweating (esp endurance events) – Sports drink Continuous intake - Drink every minutes on the trail, check urine colour and output. Dehydration -  muscle strength  coordination muscle cramps heat exhaustion, heat stroke

Exercise-Induced HypoNa Occurrence of low Na during prolonged physical activity Classically occurs in events lasting > 4hrs Non-specific symptoms: –Headache, nausea & vomiting, obtundation, seizures

Exercise-induced HypoNa Excessive fluid intake / Over-consumption The most important risk factor Drink only according to own requirement Record own requirement during training Avoid over-drinking!

Protein Build up muscle and strength 1-1.5g/kg/day Excess stored as fat, extra strain on kidney Not a quick source of energy Delay stomach emptying, takes longer to digest than carbohydrate High protein diet may increase urine production, leading to dehydration

No more than 30% of energy in exercise Decrease physical work capacity Only metabolized when CHO supply runs out Fat metabolism too slow to release energy Fatty food slows down digestion, bloated feeling in the stomach Fat

Vitamins & Minerals Play an important role in metabolism of food and in muscle function  physical activity   your need in vitamins and minerals Antioxidant clears the harmful substances released from stress of exercise

Right Diet Balanced in carbohydrate, protein and fat Nutrients come from a wide variety of food Sports diet - high carbohydrate, moderate protein, low fat Rich in vitamins and minerals

What to eat Food rich in Carbohydrate Rice Bread Potatoes Pasta/noodles Banana Power Bar, Cereal Bar  on the trail Natural Food Bar  Energy gel 

What to eat Sugar Fruit juice, Sugar drink & Candy Careful with big sugar load absorbed quickly  blood glucose   insulin  blood glucose  performance  Reactive Hypoglycemic/Sugar crash  Mix and match carbo food which converts to glucose at different speed after ingestion to maintain steady blood glucose level.

What to drink Plain water best for rehydration & cooling Sports drink (with vitamins, minerals and calories) to replenish fluid and electrolytes Bottled/powder Avoid alcohol - diuretics, affect judgement Tea & coffee – caffeine diuretic, suppress sense of hunger & thirst, drink as needed only

How to sustain good nutritional level Establish an eating pattern during training Eat & drink as frequently as possible Don’t rely on sense of hunger or thirst Try out food which works with you beforehand Gastrointestinal upset lower performance, the worst situation causing quitting of race Read the nutrition panel on prepacked food Eat tasty food which you enjoy Replenish carbohydrate and fluid after the race

Conclusion Food & drink on the trail is a personal choice, provided the combination meets your physical need Feeding is a disciplined and calculated act, should be integrated into training Plan well ahead Optimize body condition to enter race Maintain optimal nutritional status during the race Finish the race with best performance

Keys Keep your energy levels up Avoid hunger during the event Stabilize your blood-sugar level Eat frequent mini-meals on the trail Keep your fluid levels up Drink plenty of fluids before, during & after Drink before you get thirsty Keep your body & spirit up

The End

Good Luck & Enjoy !