Nutrition, Fitness & Sport

							Nutrition, Fitness & Sport
         Position 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)