Download - Sport Nutrition For Competitive Rowing
Sport Nutrition For Competitive Rowing
Cristina Sutter, MHSc., BSc (Kines)
Registered Dietitian
www.satoriintegrativehealth.com
Performance Benefits
Moderation,Food Groups,
Balance, variety, Regular meals and snacks,
Fuel and Fluids
Supplemenents
0-1% or negative?
24% Sport Nutrition
75%Healthy Diet
Optimal performance goals of sport nutrition (Burke & Read, 1993)
• ensure adequate fuel stores • prevent dehydration • achieve and maintain appropriate lean and fat
mass;• achieve gastro-intestinal comfort • promote optimal adaptation and recovery
Healthy Diet
Have Regular Meals and Snacks
(Breakfast is the most important meal)
Healthy Choices
Four Food Groups
5-15
5-15
4-6
2-4
This is where you start…….
Carbohydrate
Everyday carbohydrate :
– Total Daily Intake: 5-13 grams carb/kg/day– 1-4 hours before exercise: 1-4 grams carb/kg – During practice: 1 gram carb/kg/hour– After practice: 1.2 grams carb/kg/hour until a
meal is eaten. Best to eat a meal within 2 hours.
Glycemic Index
Hours1 2 3
Food eaten
Low GI (pasta)
High GI (potatoes)
Blo
od g
luco
seThe glycemic index is the measure of the relative increase in blood glucose after eating 50 g of a carbohydrate food, compared to a glucose drink.
Refined Carbohydrate Diet (high glycemic index)
snack
Blood glucose
Insulin
McSnack snack
Hunger!
Less refined carbohydrate diet
Oatmeal
Blood glucose
Insulin
Not hungryyet
Lentil soup
Exerciseeffects oninsulin
Protein needs
0.8
Requirement-for averageCanadian
Requirement-for enduranceathlete (use protein as fuel)
1.2 -1.4
Grams protein/kg body weight/day
1.4 -1.8
Requirement-for powerathlete (for muscle syn)
Typical Canadian diet
1.4 - 2.0
> 3
Is protein helpful during recovery?
• Doesn’t aid in fuel recovery– Filling-up on protein could
cut appetite for carbs
• Small amounts combined with CHO may aid muscle protein recovery– 250 ml Chocolate milk– 250 ml Fruit Yoghurt
Fat is important
Essential Fat: Nuts & seeds Avocado Olive & canola oils Legumes Fish Whole grains
Saturated Fat: Chocolate, Meat, Dairy
Trans Fat: • Fast food• Processed/baked goods
• Muffins, pies, cakes
• Snacks:chips, crackers, cookies
• Processed meats: hot dog, bologna,
• Frozen fries, pizza pop, chicken fingers
Fat: Too Much or Too Little?Handout page 9
• Likely too much (of the wrong) fat:– fast food & take-out meals– commercially processed foods (e.g. frozen chicken,
pizza pockets, cookies, crackers, donuts, etc.)– few vegetables or fruit– always eats desserts
• Likely too little fat:– no or very little meat,– avoids egg yolks, ‘regular’ salad dressings, nuts,
avocados, cheeses, milk, butter/margarine, and all fried foods.
– counting grams of fat in their diet
FuelsCarbohydrate *main fuel during exercise• maintains blood glucose• limited body stores: glycogen in liver and muscles• usually burned, rarely goes to fat
Fat• body fat stores (unlimited)• burned:
• In long slow distance, recovery• When glycogen runs out
Protein• body tissues (no stores)• converted to carbohydrate for energy (not desirable)• excess protein converted to fat
Fuel for Performance
Carbohydrate DuringDuring Event...Supplement with High Glycemic Index Carbs during exercise, if glycogen runs out (low stores or long/intense exercise)
• immediately (<10 min) before event can eat carbs– adrenalin suppresses insulin response
• During event, start fueling 30 min before glycogen depletion:– 30-70g CHO/hr = 0.5-1g CHO/kg/hr– 6g glucose/100ml = 400 - 1000ml/hr
What fuel are muscles burning?
• Depends on intensity:– 90 min practice (70% CHO / 30% fat)
– Regatta (100% CHO)
• Depends on what they’ve eaten:– Eat carb in the past few hours: at any
intensity/training (90%-100% CHO / 0-10% fat)
• This is GOOD for high intensity exercise!
Glycogen Stores• Muscle carbohydrate (glycogen) stores last:
– 1-2 hr at 70-90 % VO2max
– 2-3 hr at 60-80% VO2max
– 30 min at 90-130% VO2max
• If carbohydrate runs-out (glycogen depletion):• Body burns protein and fat
– Very slow fuels, can’t sustain high intensities
Outcomes of Carbohydrate Shortage“Glycogen Depletion”
• Poor endurance performance “Hit the wall”
• Sluggish brain activity, central fatigue
• Hypoglycemia– Symptoms: shake, sweat, tremble, hungry, poor
concentration– Stress response: immune system is weakened
Pre-exercise Carbohydrate• Pre-exercise meals/snacks can:
• Top-up glycogen in liver and muscle• Top-up blood glucose• Increase CHO use• Prevent hypoglycemia • Help psychologically
• Can also cause gastrointestinal discomfort, avoid:• Unfamiliar: select well tolerated foods only• Fibre (apples, legumes, vegetables, whole grains)• Fat• Protein
Pre-exercise Carbohydrate...• 3 days prior to endurance event eat a high (70%) carbohydrate diet
• 4-6 hrs before event may eat up to 5g CHO/kg (200-300g carbohydrate)– enough time to get into muscle glycogen stores
• 1-4 hours before event eat 1-4 grams CHO/kg
• 15-60 min before event avoid carbohydrate– causes insulin response, early reliance on carbohydrate and
hypoglycemia
Carbohydrate after training
• If have less than 20 hours to recover: – High glycemic index, immediately– 0.7-1 gram CHO/kg/hour until meal
• If have more than 24 hours:– 7-10 grams/kg/day works well
Put Glycemic Index to work for you
• High glycemic index great for:– Short event– Quick top-up <10 min. before exercise– Quick supplement during exercise
• Over 90 minutes– start 30 minutes before fatigue
• Drinks often most acceptable
– Quick recovery of glycogen stores (if in hurry)
Put Glycemic Index to work for you
• Low glycemic index foods great for:– Fueling longer training– Overnight recovery– When muscle glycogen stores are full – Abating hunger for longer
Rules for Recovery Following Exercise
• You need 5 hours to recover partially, 17-24 hours to replete glycogen stores completely
• Fill your muscles first:– Junk only fills your stomach
– You won’t want to eat the important stuff
• Until you’ve had your recovery carbohydrate and fluid,avoid:– Fat & excessive protein
– Too much alcohol & caffeine
Summary
• Eat plenty of carbs– Daily (5-10 grams/Kg/day)– Before exercise (1-4 g/kg; 1-4 hours before)– During exercise (>90 minutes: 0.5 to 1 g/kg/hr)– After exercise (1 g/kg/hr up to next meal)
• Unknown if protein can benefit muscle
• Get adequate protein, BUT high protein diets:• Enhance dehydration• Strain kidneys• Increase likelihood carbohydrate depletion
– Performance loss (muscles and brain)– Immune system weakened
In general, what to eat more of?
• Fruit (fresh, dried, canned)
• Vegetables (dark colours are best)
• Whole grains (cereals, bagels, bread, crackers, pasta, rice)
• Nuts & Seeds (not roasted)
• Beans (canned = easy)
• Yogurt, milk (chocolate is OK)
What and when?
• Before morning training– Cereal and juice
– Yoghurt and banana
– Crackers and milk
• After morning training– Water water water
– Bagel and peanutbutter
– Bag of cereal, juice
• At lunch– A real lunch with fruit &
milk
• After school– Baby Carrots
– Trail mix
• After practice– Water water water
– Fruit bar or raisins
• Supper and snack
Fluids for Performance
Fluids: Watch for Dehydration
• Reduced performance at 2% weight loss through dehydration ~1.3 kg
• Signs:– small amount of dark yellow urine– reduced sweat, overheat– Stomach cramps– headache, sluggishness, reduced concentration
Fluid Before Practice or Race
• 600-1000ml 1 hr before
• 400-500ml of that within 15min before
Drink During Practice
• Large gulps are better than sipping
• 300ml up to 2L per hour • Start with 600 ml @ 20 min, then repeat
150 ml every 20 min. during practice
• Add 1/10 tsp salt per Litre water = 0.5ml Na/L H20
Drink After Practice or Race
• 1 kg weight loss = 1 L water loss
• Dehydration at 1% weight loss ~1.5 lbs
• Need to replace 150% of loss
• Monitor weight: • Pre exercise wt 60 Kg
• Weight after exercise 58 Kg
• Fluid loss - 2 kg = 2 L H2O
• Need to rehydrate with 150% = 3 L
Electrolytes
• Replacement rarely necessary during activity– unless replace excessive sweating with copious amount
of water
– sweat loss = 1150mg Na/L sweat
• Need electrolytes: Sodium and Potassium– At end of day
– Don’t avoid salt
– Drink tomato juice, V8, skim milk
– Eat lots of fruit, potatoes.
Water or Sports Drink?
– For rowers, hyponatremia/water intoxication is rare
Sports drinks• Useful for– Pre-exercise carb top-up
– Extra carb for long workouts (>90 min)
• Not so good
– For recovery, require B vitamins to process carbohydrate
What does a Training day look like?
Breakfast1 bowl (400 ml) cereal with skim milk2 pieces toast 4Tbsp Peanut butter1 orange
90 rowing practice: water, water, water
Snackwater, water, water banana
Lunch12” turkey sub2 cookies3 carrots, celery
250 ml skim milk 1 applewater, water, water
Snack1 c fruit yogurt2 kiwi
* 60 minute dryland training: water, water
Supper500 ml riceveg/meat stir frybowl ice cream
What does a Competition day look like?
Breakfast1 bowl (400 ml) cereal with skim milk2 pieces toast 250 ml orange juice
10 minute race
Snackwater, water, water banana
Lunch12” turkey sub3 orange250 ml skim milk 1 applewater, water, water
Snack1 c fruit yogurt2 kiwi
20 minute race
Snack: water, bagel and peanut butter
Supper500 ml riceveg/meat stir frybowl ice creamwater, water, water
Dessert: chips, pop
Weight Cutting• lose 5% body weight in 24 hours
• weigh-in can be 2 to 20 hours pre-event; single or repeated
• methods include: fluid restriction, rubber suits, saunas, exercise, laxatives, vomiting, spitting, diuretics
Effects of Weight Cutting
Recovery is variable, 21% in 1 hour to 42% in 3-5 hours Recovers in 5 - 24 hrs with rehydration + 4gcho/kg Reduces muscle endurance and strength Reduced anaerobic performance, lactic acid build up
Does not recover with Rehydration: Reduced aerobic performance: hypovolemia, increase core
temp, decrease cardiac output, VO2 max Reduce muscle glycogen stores, if low carbohydrate intake
Weight Cutting Recommendations
performance declines if wt loss >4% and have less than 5 hours to recover
if have 5+ hours: 4 - 8% loss rapid will be OK for strength and anaerobic
• Sauna does not reduce performance as much as active dehydration
• high CHO diet during low Calorie phase– 4 g CHO/kg (65-70% CHO), 1.6g prot /kg
Gradual Weight Loss
• Over many weeks• Does not reduce vo2max• Is it possible? Is athlete over-fat? Genetically doomed?
• Look for ‘nice’ but not ‘necessary’ foods in diet. Leave in a few treats.
• Look for ways to burn extra energy• To avoid glycogen depletion if diet is <2200 cal/day,
then have high carb foods
Weight gain in athletes
Most important nutritional factor is energy, especially carbohydrate
Need overload, intensity, progression and recovery
• Recovery: muscle protein synthesis:• reduced during and immediately after training
• CHO (1 gram/kg/hour) can increase synthesis. Benefits of amino acids at this point uncertain.
• Need >24 hours recovery between sessions to maximize gains