Transcript Trailwalker2008NutritionforTW20080607

OxfamTrailwalker
2008
Nutrition for Trailwalkers
Dr Janice Tsang
7th June, 2008
Trailwalker is an endurance
event requiring proper
physical training & nutrition to
sustain good performance
Failure to Complete TW
• Failure to complete trailwalker
– Physical injury / pain
– Muscle cramps / fatigue
– Dizziness, blackout / hypoglycemia
– Vomiting / dehydration
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
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
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
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
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 / Overconsumption
The most important risk factor
Drink only according to own requirement
Record own requirement during training
Avoid over-drinking!
Protein
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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
Fat
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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
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
What to eat
Food rich in Carbohydrate
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Rice
Bread
Potatoes
Pasta/noodles
Banana
Power Bar, Cereal Bar
Natural Food Bar
Energy gel
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on the trail
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
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
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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
www.healthandlifestyle.co.nz
www.dietitian.com
Good Luck & Enjoy !