Sport Nutrition For Competitive Rowing

Cristina Sutter, MHSc., BSc (Kines)

Registered Dietitian

www.satoriintegrativehealth.com

csutter@sfu.ca

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