Optimal Nutrition for Trailwalkers: Tips from Dr. Janice Tsang

1. OxfamTrailwalker 2007 Nutrition for Trailwalkers Dr Janice Tsang

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

3. Nutrition • Integral part of training • Exercise nutrient needs • 70 kg person at 6 kph on level ground - 360 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

4. Carbohydrate • Main source of energy in exercise (65 - 70%) • 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

5. 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. 24-48hrs before the event

6. 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 15-30 minutes on the trail, check urine colour and output. • Dehydration -  muscle strength  coordination muscle cramps heat exhaustion, heat stroke

7. 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

8. 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!

9. 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

10. Fat • 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

11. 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

12. 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

13. What to eat Food rich inCarbohydrate • Rice • Bread • Potatoes • Pasta/noodles • Banana  • Power Bar, Cereal Bar  on the trail • Natural Food Bar  • Energy gel 

14. 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.

15. 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

16. 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

17. 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

18. 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

19. The Endwww.dietitian.orgwww.eatright.org

20. Good Luck & Enjoy !