SPORTS NUTRITION

20 MARCH 2015

Why Are Good Nutritional Practices Important For Athletes? 

•      Enhances Training and Competitive Performances•    Provides Adequate Nutrients For Recovery Between Sessions•    Maintains Good Health•    Sustains Growth & Development

“A Proper Diet Can’t Make An Average Athlete Elite, But A Poor Diet Can Make An Elite Athlete Average”

 

  

What Are The Issues?

•      Energy – Macro Nutrient Intakes For Various Sports – Do They Differ? •      Hydration – does it affect performance? •      Timing – When should athletes eat/drink?

CarbohydratesWhy Do Athletes Need Them?

•      Primary fuel source for most groups of athletes •      Primary fuel source for endurance athletes is fat but limiting fuel source is carbohydrate

 

CARBOHYDRATESWhat Are The Foods Sources?

Grain Products Vegetables and FruitMilk ProductsExtras

Carbohydrates –How Much Do Athletes Need? 

•      Endurance Athletes & Athletes Who Train Exhaustively On Successive Days –60-70 % of total energy–If consume high energy

diets then need 7-10 g/kg/d

•      Recreational Athletes & Most Active People – 55-60 % of total energy

 •      Strength Athletes - ~ 55–65% of total energy

–   Depends on Training Schedule

FATWhy Do Athletes Need It?•      Provides Fat Soluble Vitamins (A,D, E, K)•      Supplies Essential Fatty Acids•      Taste•      Aids With Satiety•      Primary Fuel Source For Endurance Athletes

FAT

Where Athletes Get It?

•      Naturally Present In Many Foods–   Hidden vs Added Fats

 •      Majority Of Fat In Diet From Fats & Oils

–   i.e. Butter, Margarine, Salad Dressings, Sauces

FAT-too much can slow down the athleteHow To Reduce Intake•      Choose Lower Fat Foods  i.e. Leaner meats, lower fat dairy products,

low fat salad dressings•      Trim Fat From Meats, Skin From Poultry•      Prepare Food Without Adding Fat•      Choose Appropriate Serving Sizes•      Avoid Adding Fat When Possible  i.e. butter, margarine, gravy,

mayonnaise, sauces

Protein

Why do athletes need it?

•builds muscle and bone

•make enzymes-required for energy and building molecules

•to meet all other functions of proteins

Protein

Where do athletes get it?

•Meat and alternatives

•Milk and alternatives

•Grain products

Protein Recommendations

Dietary reference intake-for healthy non-athletes

–   0.80 grams/kg body weight/day Athletes:

–   Strength: 1.4-2.0 grams/kg body weight/day

–   Endurance: 1.2-1.6 grams/kg body weight/day

Protein RecommendationsHow much do athletes need?  

Example•      80 kg Male •      Normally Active: 0.80g/kg BW/day~ 64 grams/day•      Strength Athlete: 1.4-2.0g/kg BW/day ~110-160 g/day•      Endurance Athlete: 1.2-1.6g/kg BW/day ~ 95-130g/day   

Protein Recommendations

 

Can You Consume Too Much Protein? No Adverse effects have been reported for Healthy Athletes when Protein intakes are <2.0 g/kg BW/day

Water-Why Do Athletes Need It?

 •      Water Assists in the Digestive Process & Elimination

of Waste Products •      Major Component of Blood •      Acts as a Coolant for Working Muscles &

Maintains Normal Body Temperature

Water-Where Do Athletes Get It?

  •      drinks-water, juices, milks, sports drinks, tea, coffee •      semi-solid and solid foods have some water

Water-how much do athletes need?

  •      replace what lose-assuming normal water balance to start •      normal water balance means sufficient water where and when it is needed in the body

• avoid dehydration

Fluid Losses Experienced During Training

•      Athletes typically only replace 30-70% of sweat losses during a training session•      Therefore, athletes are moderately dehydrated post-exercise•      Continued fluid loss in recovery phase:

   Sweat   Urine production

 Goal:•      Replace fluid lost during training prior to next event 

Dehydration•      Starts When fluid Loss Exceeds 1% of Body Weight •      Symptoms:

–   Headache–   Irritability–   Fatigue

Impact of DehydrationReplacing Fluids During Activity•      Thirst is not a Good Indicator•      Water is Best Fluid if Activity is Under 1 Hour•      Activities > 1 hour would benefit from a carbohydrate

source (6-10% CHO)•      Cool Fluid in Small Volumes•      Drink ~ 125 ml every 10-20 minutes

Is Plain Water Enough?Recommendation:•      Athletes experience >2% loss of body weight from

dehydration•      Consume ~150-200% of volume lost•      Fluid should contain sodium•      Also consume some foods containing sodium

post-exercise •      Recommended levels of sodium: 50mmol/Litre•      Sports Drinks: 10-25 mmol sodium/L 

Remember:•      When selecting a fluid for re-hydration, the fluid has to be palatable to the athlete. This has been shown to increase fluid consumption

Vitamins and minerals

Why do athletes require them?- to allow their functions

Where do athletes get them-in carbohydrate, fat and protein containing foods

How much do athletes require-amounts found in sufficient intake of foods containing carbohydrate, fat and protein

Supplements are a waste of money

PRE-COMPETITION MEALS

•Assume a Sound Training Diet Has Been Consumed

 •    Replace Liver Glycogen Stores That Have

Become Depleted Over Night 

Pre-Competition Meals

Purpose:•      To Prevent Hunger During the Competition •      To Assist with Adequate Hydration •      To Increase the Physical & Psychological

Comfort of the Athlete

Pre-Competition Meals

Timing2-4 hours before event to allow adequate digestion•      Meal Size ~ 500 kcals•      Meal Time ~ 2-4 hours before•      Competition – If < 2hours before

competition, smaller meal is required

Foods Must Be Familiar To The AthletePre-Competition Meals

Composition:

•      High Carbohydrate•      Plenty of Fluids•      Moderate in Protein Content•      Low in Simple Sugar Content•      Low in Fibre and Fat•      Low in Salt & Caffeine

Fueling After ActionReplace:

–   Water–   Glycogen Stores–   Electrolytes (and other minerals)

- Plenty of Fluid -1.5 litres of fluid for every kg weight loss

- Carbohydrate–   Within 2 hours after activity–   Fruit, juice, crackers, bagels,

lower fat yogurt–   Ensure a full meal with adequate

intake

Nutrition Does Impact Performance!