Nutrition and Physical Activity

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Nutrition and Physical Activity

• Chapter 13

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Fitness

• Depends on physical activity and exercise (not
  body type!)
• Regular physical activity
• Promotes health
• Reduces risk of developing many diseases
• Heart disease
• Cancer
• Stroke
• Diabetes
• Hypertension

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More Benefits of Fitness

• Restful sleep
• Nutritional health
• Optimal body composition
• Optimal bone density
• Resistance to infectious diseases
• Lower incidence of anxiety depression

• Lower risk for some types of cancer
• Strong circulation lung function
• Stress reduction
• Cortisol reduction
• Strong self image
• Lower risk of dementia

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How much should I do?

• Highly individual
• Just 15-20 min/day starts to reduce disease risk
• Minimum for optimal health 2.5 hrs moderate or
  1.25 hrs vigorous activity
• Not an upper limit!
• Good to spread out over the week
• How much is too much?

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Developing Fitness

• Minimizing risk of overuse injuries
• Be active all week
• Use proper equipment and attire
• Use proper form
• Include warm-up and cool-down activities
• Challenge your strength and endurance a few times
  a week
• Mix it up!
• Pay attention to body signals

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Developing Fitness

• Muscle conditioning
• Fit muscles use oxygen efficiently
• Increased mitochondria and vasculature
• Reduces hearts workload
• Burns fat longer
• Balanced fitness program
• Activities you enjoy doing
• Addresses all aspects of fitness
• Strength, endurance, flexibility
• Each has specific benefits

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Resistance Training

• Purpose
• Build muscle mass
• Increases metabolism!
• Develop and maintain muscle strength, muscle
  power, and muscle endurance
• Benefits for prevention of chronic diseases
• Maximizes and maintains bone mass
• Improves posture reduces risk of back injury

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Nutrition Physical Performance

• Performance and recovery both enhanced by optimal
  nutrition
• We need all essential nutrients to power movement
• 3 energy systems
• ATP-CP, lactic acid, and oxygen
• All 3 systems always active and work together
• ATP-CP (creatine phosphate)
• Stores of ATP and CP only power muscles 3-15
  seconds
• Muscle and liver glycogen needed to continue
  contraction

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Creatine Phosphate

• Popular supplement (ergogenic aid)
• Studies show improvement in muscle strength and
  power
• No benefit for aerobic training
• Possible side effects
• Weight gain (water retention)
• GI symptoms nausea, diarrhea, abdominal pain
• Rash, anxiety, headache, fatigue
• Not appropriate for people with kidney issues
• Should be avoided in children, adolescents,
  pregnant women, nursing mothers, diabetics

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Anaerobic vs. Aerobic

• Anaerobic activities and fatigue
• Lactic acid energy system
• Anaerobic glycolysis leads to drop in pH
• Impairs glycolysis, inhibits binding of calcium
• Aerobic activities and endurance
• Oxygen energy system
• Oxidative metabolism of energy nutrients
• Increased blood flow to muscles oxygen!
• Produces much more ATP, but at slower rate
• Uses glucose and fatty acids

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Endurance

• As long as ATP supply meets energy needs,
  activity can continue
• Rate/intensity of activity influences energy
  system used
• Anaerobic exercise CP and glycogen rapidly
  depleted
• Level of training highly influences shift to
  anaerobic metabolism
• Number of mitochondria and efficiency of oxygen
  delivery increase with training

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Glucose Use During PA

• Exertion
• Liver breaks down glycogen
• Release glucose into bloodstream
• Muscles use glucose and stored glycogen
• Muscle fatigue when glycogen is depleted
• Glycogen storage limited
• Intensity of activity
• Impacts how long glycogen will last
• CHO post-workout restores glycogen, spares muscle
  tissue

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Protein Use PA

• Not a significant part of fuel mix for most
• Used in muscle building
• Synthesis suppressed during activity accelerates
  afterward
• High-quality protein consumption
• Enhances muscle protein synthesis
• What is a high-quality protein?
• Protein needs are higher for endurance and
  strength athletes
• Need adequate CHO, as wellwhy?

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Recommended Protein Intakes for Athletes

• Endurance athlete 1.2-1.4 g/kg body weight
• Strength athlete 1.6-1.7 g/kg body weight
• Everyday adults minimum of 0.8 g/kg body weight
• Max. usable amount for adults 2.0 g/kg body
  weight
• Risks of excessive protein intake
• Dehydration
• Mineral losses

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Vitamins and Minerals to Support Activity

• Roles in supporting activity
• Assist in releasing energy from fuels
• Transport of oxygen
• Multiple vitamins and minerals, as well as
  protein, involved!
• Supplements
• Vast majority do not enhance performance of
  well-nourished people

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Fluids and Electrolytes to Support Activity

• Fluid replacement via hydration
• Hydrate before activity
• Drink extra fluid in the days before event
• Rehydrate during and after activity
• Fluids for everyday, active people
• Plain, cool water
• Fluids for endurance athletes
• May benefit from mineral and CHO-containing
  beverages

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Sports Drinks vs. Water

• Sports drinks
• Hydration is critical to optimal performance
• Water is best for most people
• Sport drinks offer the following
• Fluid
• Glucose
• Sodium and other electrolytes
• Some prefer the flavor

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Dietary Strategies for Active People

• Hydrate
• Thirst is a late signal of need
• Choose nutrient-dense foods
• Vitamins minerals
• Consume adequate energy
• Need all energy-yielding nutrients
• CHO, protein, and fat
• Meal frequency and balance
• Stable blood glucose means stable energy levels
• Optimal maintenance of lean tissues

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Timing of Meals

• 30 min-1 hour pre-workout
• Protein-based snack or small meal
• Timing is individual
• Not for everyone! Depends on GI picture.
• During workout
• Sip water
• Post-workout
• Best time to consume CHO-rich foods
• Include protein! Balance.
• Fitness goals highly individual!
• Timing strategies vary depending on goal
• Ex carbohydrate loading