nutrition, fitness & sport

Nutrition, Fitness & SportPosition Paper

of DC, ADA & Am.College Sports Medicine

Joint Position Paper

“…physical activity, athletic performance, and recovery from exercise are enhanced by optimal nutrition”

“…appropriate selection of food and fluids, timing and intake, and supplement choices for optimal health and exercise performance”

Rodriguez, DiMarco, & Langley, 2009

Energy Needs

What factors affect energy needs of athletes?

What sports might see weight cycling by competitors?

Weight Loss and Physical Activity Weight loss aims to reduce fat Rapid weight loss

• lean tissue/muscle • Fluid• Increased chance of regain

Is weight the only way body composition changes are seen?

Body Composition

Standards• BMI 20-25• % body fat – males 15-18%; females 20-25%

Minimum level for health • – males 5%; females 12%

Why are body weight and weight for height not good indicators of healthy body size?

Body Composition

Techniques to measure/estimate body composition• Hydrostatic (under water) weighing• Air displacement plethysmography• DEXA• Anthropomtric measures – skinfolds • Bioelectrical impedence

Hydrostatic Weighing

Air Displacement Plethysmography

DEXA

Skinfolds

Bioelectric Impedance

Energy Recommendations

Accepted macronutrient Distribution Ranges• Recommended intakes of

energy-yielding nutrients

• CHO – 7-8 g/kg

• Pro – 1.2-1.4 g/kg endurance

– 1.2-1.7 g/kg strength

• Fat – 20-30%

Nutrients

Do athletes require more protein than non-athletes?

• 0.8-1.2-1.5 g/kg Which minerals are of primary concern with athletes?

Vitamins & Minerals

Micronutrients of concern in athletes• Calcium

• Vitamin D

• B vitamins

• Iron

• Zinc

• Magnesium

• Antioxidants• Vitamins C & A, beta carotene, selenium

Hydration

Important to athletes• Heat production• Affects muscle strength, endurance and

coordination• Cramping, heat exhaustion and heat stroke

all of concern

What conditions create dehydration risk?

Hydration

How can one ensure maximal hydration?• 5-7 mL/kg 4 hr before

event• Aim to prevent loss over

2% body wt• Replace sweat losses

• 1-1.3 L/kg lost beginning early after event

Are specialized products needed to ensure adequate hydration?

Sodium (Na) in Sports Drinks

Not needed, unless exercising strenuously for more than 1 hour• 600 mL bottle Gatorade contains ~275 mg

Na• Daily Na limit 1500-2400 mg

Not for refreshment or snack Flavoured water better choice if plain

water not personally acceptable

Training Diet 2 fundamental differences between athlete’s

diet and general population? Pre-exercise meal (2-4 hr before event)

• Sufficient fluid, low in fat and fibre, 200-300g CHO, some protein, familiar foods

During• CHO in form of glucose 0.7 g/kg extends endurance

performance – every 15-20 min Post-game

• Depends on timing of next event • Not needed if over 1 day until next intense workout

• CHO within 30 minutes • 1-2 g/kg every 2 hr for 6 hr• High GI foods replace glycogen losses better

Ergogenic Aids

How should ergogenic aids be evaluated? What are some of the ergogenic aids

currently marketed? What types of effects have been proven

for these substances?

Nutritional Professional

Career path:• Undergraduate, internship, and work

experience• Knowledge of exercise science and business• At least 1-2 years employment in dietetics

• What roles does the nutrition professional have in the area of sports nutrition?

Required Reading

Lichtenstein, & Ludwig, 2010. Bringing back home economics education.

James, & Adams, 1998. Curriculum integration in nutrition and mathematics.

Graham, Beall, et al., 2005. Use of school gardens in academic instruction.

NS Dept. of Education & Health Promotion and Protection. Food and nutrition policy for Nova Scotia schools (web)