Sports Nutrition – Eat to Compete

Mark Mirabelli, M.D.Assistant Professor

Depts. of Orthopaedics and Family Medicine

University of Rochester

GoalsUnderstand basics of general nutritionRecommendations for pregame and

postgame mealsBrief words on sports supplements

Key Nutrition and Performance Goals

Optimize/maintain hydration/ electrolyte status Maximize/maintain fuel supplies Maximize protein synthesis to increase lean body mass Accelerate recovery from a strenuous bout of activity

Carbohydrates ENERGY Protein Growth, Repair Fat Energy stores Water Fluid balance

Vitamins Body Processes Minerals Body Processes

Nutrient Function

•4 calories for each gram•Provides ENERGY for athletes!•50%-60% of our total diet

•Simple carbs for fast energy• Candy, Soda, Fruit, Sugary foods

- Complex for sustained energy• Pasta, Rice, Breads, Grains, Starchy foods

Carbohydrates

Maximize Glycogen Synthesis Glycogen - primary fuel source during moderate to high intensity exercise Muscle glycogen repletion is slow, and can take 24 hrs. Exponential relation between rate of glycogen resynthesis and recovery time Restoration of muscle glycogen most critical factor for recovery/ subsequent performance

Glycogen and Resistance Training: Resistance exercise reduces glycogen by approximately 30-40%;

Resynthesis is slow unless energy substrates are provided; Provision of CHO after exercise enhances resynthesis of glycogen; Provision of protein and fat with CHO after exercise does not impair resynthesis.

Comparison of Diets Low CHO diet (40% kcal from CHO)•Double cheeseburger•Medium fries•Chocolate milkshake

High CHO diet (70% kcal from CHO)•12 inch sub sandwich (lots of vegetables & no mayo)

•500 ml apple juice•250 ml chocolate milk

•banana

Carbohydrate Snacks Foods supplying 50g CHO•500 ml Juice•3 Medium pieces of fruit•1 honey sandwich•2 breakfast bars•1 sports bar (check label)•1.3 bagels•1/2 cup dried fruit•1 cup white rice•1 baked potato

Critical Re-Fueling Interval

Recovery Recovery

Exe

rcis

e

Exe

rcis

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Re-FuelingInterval

Re-FuelingInterval

Phases of Timing Nutrient Intake

Summary To replete glycogen stores after exercise, carbohydrates should be eaten within 15 min and repeated every 2 hr for 4 to 6 hr.

Ingesting protein following resistance exercise should enhance protein synthesis and may inhibit protein catabolism.

For recovery from exercise, food with a CHO to protein ratio of about 4 to 1 should be ingested within 30 minutes after exercise.

•4 calories for each gram•Growth and Repair of all tissue (muscle etc)•10%-15% of our total diet•Red meat, chicken, pork, Fish, Eggs

Protein

150 LBS 10% body fat 90% lean body

150 LBS 35% body fat 65% lean body

Who needs more protein?

•9 calories for each gram (more than double carbs and protein)

•Padding, protection, hormonal response•25%-30% of our diet

• TWO TYPES:• Unsaturated (15%-20%) GOOD fat (plant)

– -Liquid at room temperature– Oils, Nuts, Seeds, Avocados etc.

• Saturated (10%) BAD fat (animal)– -Solid at room temperature– Red meats, fried foods, butter

Good Fat = Plant based Oils

Nuts are healthy

Olive Oils

Nutrient dense

Hydration Status and Guidelines

Regulation of Water Balance Thirst•Daily water balance varies between 0.2 and 0.5% each day, independent of climate

Metabolism•Daily turnover between 3.3 and 4.5 L/day (6 L for very active populations) for sedentary and active populations

Requirements•Low activity: 4.5 - 8 L/day•High Activity: 6 to 12 L/day

Losses•1 - 2 L/h for athletes

Dehydration and

Performance

Dehydration and Performance

Impaired temperature regulation

Reduced muscular

endurance

Reduced strengthReduced

endurance capacity

Heat cramps

Severe heat cramps

Heat strokeComaDeath

We

igh

t L

os

s (

% B

od

y W

eig

ht)

8

6

4

2

Urine color test for dehydration

Lemonade—The good

Apple juice—The bad

Tea—The ugly

Monitoring HydrationStatus

1

2

3

4

5

6

7

8

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Fluid recommendationsClear liquids up to 1 hour before event

Drink 3-8 fl oz of water every 15-20 min when exercising for < 60 min

Drink 3-8 fl oz of a beverage with CHO (5% to 8%) and electrolytes every 15-20 min when exercising> 60 min.

Simple liquid carbs after event

DO NOT DRINK MORE THAN 1 L or 1 Qt/hr during exercise.

MineralsMineralsNecessary for food metabolism, energy production, and protection of body tissues

Iron and Zinc supplementation beneficial in those with deficiency

Sparse evidence– Magnesium, Copper, Selenium, Chromium

VitaminsVitamins Required nutrients in

the diet (A,B,C,D,E,K) Traditionally no need to

supplement dietary intake

No advantage to ingesting “mega” doses

Can be necessary in restrictive type diets to replace lost intake

USDA My Plate

Selected Messages for ConsumersBalancing CaloriesEnjoy your food, but eat less.Avoid oversized portions.

Foods to IncreaseMake half your plate fruits and vegetables.Switch to fat-free or low-fat (1%) milkMake half your grains whole grains.

Foods to ReduceCompare sodium in foods like soup, bread and frozen meals and choose the foods with lower numbers.Drink water instead of sugary drinks.

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Balancing calories

Enjoy your food, but eat less

Avoid oversized portions

Nutrient Dense and Non-Nutrient Dense Forms of Sample Foods

What A Typical M.S./H.S. Athlete Eats Prior to Activity:

Breakfast: 0 calories Lunch: 450-550 calories•Chips = 100 calories •1 slice of Pizza = 200-250 calories•Gatorade or other drink = 150-200 calories

Total: 450-550 Calories Prior to Activity!

Caloric Need For Practice or Game

•Football: 900-2700 •Basketball: 600-1800•Running: up to 1500 •Wrestling: up to 1800 •Baseball: 450-1200 •Dance/Cheerleading: 450-1000

•TV or Reading: up to 270

ARE THOSE 500 CALORIES GETTING THE JOB DONE?

It takes 1- 4 hours for food to leave your stomach

High Carb foods are digested quickly

High Protein foods can increase water requirements

Foods high in Fat can stay in your stomach for more than 4 hours

Best choice for pre-game meals is something high in Carbs - easy to digest

and becomes quick energy !

The Pregame Meal

Pre-Event Meal Goals “Top off” glycogen stores Optimize hydration

Empty upper GI tract

Pre-Event Meal Meal Composition High in carbohydrates•mixed complex and simple

Reasonably low in fats and protein Low in dietary fiber

Pre-Event Meal Composition (cont.) High in fluids Individualize •Use familiar foods

Pre-Event Meal Timing of meal•Complete > 2 hours before event

Individualize (3-4 hours better for some)

1994 Dietary Supplement Health and Education Act 1994 Dietary Supplement Health and Education Act (DSHEA)(DSHEA)

• Intent: allow consumers access to nutrition based supplement

• FDA no longer responsible for the purity or safety of dietary supplements

• responsible for taking action against UNSAFE dietary supplements after market

• Supplement manufacturer is responsible safety, efficacy but do not have to provide EVIDENCE

• No approval or product registration required

• FTC responsible for regulating advertising claims/labeling

• Can make health, nutrient, or structure/function claim NOT disease claim

Lack of Regulation and EvidenceLack of Regulation and Evidence

Few well designed studies exist

Most studies showing benefits of supplements are biased (funded by manufacturer)

Few patients actually studied Placebo effect (sugar pill) may account for up to 30-50% of the benefit of supplements

Supplements Conclusions

•Some supplements improve performance somewhat in some athletes some of the time

•Supplement use is ubiquitous•Theory is better than reality - many claims of supplements to improve sports performance are untrue, overstated or taken out of context

•There are few or no studies of most supplements in athletes

For More Information

Web resources:•www.usada.org•www.wada-ama.org•www.drugfreesport.com•www.choosemyplate.gov