Sports Nutrition:The Power to Influence Exercise Performance

May 21, 2014

Presenter:

Kristine Clark, PhD, RD, FACSM   Director, Sports Nutrition; Assistant Professor

   Penn State UniversityModerator:

James M. Rippe, MD – Leading cardiologist, Founder and Director, Rippe Lifestyle Institute

Approved for 1 CPE (Level 2) by the Commission on Dietetic Registration, credentialing

agency for the Academy of Nutrition and Dietetics.

NUTRI-BITES®

Webinar Series

Original recording of the May 21, 2014 webinar and PDF download of presentation available at:www.ConAgraFoodsScienceInstitute.com

Based on this webinar, learners should be able to:State why carbohydrate rich foods are optimal for athletic performance and how they play a role in exercise recovery State how macronutrients are used during low, moderate, and long duration exercise and what foods to recommend based on how someone exercises Describe the role protein plays in recovery from exercise and how much protein an exerciser needsIdentify optimal fluids a physically active person could drink before, during, and after exercise Identify strategies to share sports nutrition messages with exercisers 

NUTRI-BITES®

Webinar SeriesSports Nutrition:The Power to Influence Exercise Performance

Nutrient-Related Fatigue

Fatigue is the inability to maintain a given or expected force or power output.

Blood glucose levels fall.

Level of fatty acids in the blood increases.

Proteins provide an increased contribution to energy.

Exercise capacity progressively decreases.

Maintaining ATP levels in muscle is necessary for exercise

• Breakdown of 1 mole of ATP via myosin ATPase = 7 calories of free energy

• Muscles need both quick AND sustained energy

• Decrease in muscle ATP = fatigue

• Body has multiple mechanisms to prevent a fall in the level of ATP in muscle

•Exercisers should start out with a full supply of glycogen – especially if exercise will last awhile•Within 60 min. of exercise, glycogen in liver is depleted, 50% of glycogen in specifically exercised muscles is also depleted

•Within 2 hr of exercise – all glycogen is depleted – performance declines rapidly, exercise difficult to continue

General Recommendations for CHO Intake for an Exercising Individual

• 5-12 g CHO/kg body weight per day• Have CHO-rich sports drink within an hour after

exercise• Post-exercise recovery meal should contain

nutrient-rich, high-glycemic index CHO sources + protein

• Exercise sessions <8 hours apart, begin CHO intake as soon as possible after 1st session

• Exercise sessions >24 hours, consume a CHO- and nutrient-rich diet

• Ensure adequate caloric intake

Intensity is related to the amount of oxygen that can reach the muscles

• Cardiovascular and respiratory systems function to bring in oxygen to the body through the lungs and transport it to all the cells of the body

• Fitness levels are dependent upon the ability to deliver adequate amounts of oxygen to active muscles

• More intense exercise = Less oxygen to muscles

Fuel mix relative to exercise intensity

How duration of exercise affects which fuel is utilized

Food recommendations for various exercises

• Walking: eat balanced meals, eat small amount of carb rich food 30-60 min. before

• Jogging or other aerobic exercise: eat balanced meals, drink and eat carb rich snack prior to exercise. Duration matters: drink every 20 min., if longer than 60 min. eat carb snack during exercise

• Soccer, basketball, lacrosse: high intensity, short burst activities: eat balanced meal 2 hr before, eat carb snack 1 hr before game/practice, drink carb beverage during game breaks

• Marathon, triathlon, long hike/bike: Eat a high carb dinner the night before, eat a meal 2 hr prior to event, carry carb snacks to eat every 60 min., drink carb beverages every 20 min. during exercise

Protein and Exercise• Amino Acids are oxidized in small amounts during physical activity• Increased protein synthesis must be balanced with protein

breakdown• Regular and modest amounts of physical activity require very small

– if any increase in protein needs

• Evidence: Only endurance types of exercise require more protein– Endurance exercise: increased oxidation of BCAA– When carbohydrate intake is suboptimal, protein can contribute up to

10% of energy expenditure during exercise– Leucine appears (in some studies) to be the BCAA that is oxidized at

the greatest rate

Endurance vs Resistance Exercise• The intensity and duration of these exercises influences protein synthesis

after exercise (recovery)

After endurance exercise: increase in mitochondrial protein synthesisAfter strength training: increase in myofibrillar

• Low-moderate intensity exercises do not impact muscle protein turnover

• To maintain nitrogen balance:Endurance athletes: 1.2-1.4 gr/kg/dStrength athletes: 1.6-2.0 gr/kg/d

• Training has a protein–sparing effect

Timing of Protein Intake“The window of anabolic opportunity”

• 20-30 grams of protein after exercise • Eat both carbohydrates and proteins as soon

after exercise as possible (within a 2 hr frame)• After strength training – muscle protein

synthesis remains high up to 48 hr post exercise

• Eating regular meals with 20-30 g protein in all meals (B, L, D) – spreading it out

• High quality protein: EAA

Foods to Eat after workouts

Carbohydrates

• Juice or sport drinks• Fruit• Bread, bagels, crackers• Pretzels• Granola bars, energy bars• muffins

Proteins

• Milk• Yogurt• Peanut butter• Hard boiled egg• Beef jerky, any meat• Protein bars

Optimal fluid intake: prevent dehydration

Reaching exercisers with sports nutrition messages

1. Health clubs, fitness centers, YMCA: presentations, written materials, newsletters, private clients

2. Local newspapers: fitness columns, weekly Q and A

3. Local grocery stores: sports nutrition shopping, cooking classes, newsletter or shopping guide

4. High schools – contacting coaches who could use assistance with team nutrition

5. Parent organizations: helping parents feed their athletes

Sports Nutrition: Summary

1. Carbohydrate rich foods provide optimal energy source for physical activity and prevent exercise fatigue

2. Protein and carbohydrate rich foods eaten as a snack or meal after exercise replace energy stores and aid in optimal recovery

3. Eat before exercise to optimize energy levels, eat during exercise if exercise is long lasting

4. Eating as soon after exercise is a strategy for rapid recovery (2 hr anabolic window)

5. Depending on how long exercise will last should determine how much you need to eat before and after exercise

6. Drink early and often during exercise, don’t wait until thirsty, replace lost body water as it’s lost

Recommended Reading and Resources for RD’s/RDN’s

1. Deutz , N & Wolfe, R Is there a maximal anabolic response to protein intake with a meal, Clinical Nutrition, Nov. 2012

2. Lunn, W, et al Chocolate milk and endurance exercise recovery: protein balance, glycogen and performance, Med Sci in Sp and Ex. 2012.

3. Shirreffs, S et al Milk as an effective post-exercise rehydration drink. British J of Nutr, 98,2007.4. Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports

Medicine: Sports Nutrition, March, ‘09, 109:3, p 509-526 (online and full text, is currently being updated)5. Buell, J. et al, National Athletic Trainer’s Association Position Statement: Evaluation of Dietary Supplements

for Performance Nutrition, Journal of Athletic Therapy, Feb. ‘13, 48(1):124-136. (online, full text)6. Sammarone, P. et al, National Athletic Trainer’s Association Position Statement: Safe weight loss and

maintenance practices in sport and exercise, Journal of Athletic Therapy, ‘11, 46(3):322-336. (online and full text)

7. Sports Nutrition Care Manual – eatright.org, written by a variety of Certified Specialists in Sports Dietetics. Covers all topics of sports nutrition

8. Krieder, RB et al, International Society of Sports Nutrition Review: Research and Recommendations, Journal of the International Society of Sports Nutrition, ‘10, 7:7. (online and full text)