sports nutrition: eating for peak performance biol 103, chapter 11
TRANSCRIPT
Nutrition and Physical Performance
• “Exercise is medicine”• Physical fitness is made up for 5 components:
1. Cardiorespiratory fitness: ability of body’s circulatory and respiratory systems to fuel during sustained physical activity.
2. Muscular strength: ability of muscle to exert force during an activity
3. Muscular endurance: ability of muscle to continue to perform without fatigue
4. Body composition: relative amount of fat to lean body mass.
5. Flexibility: the range of motion around a joint
Figure 11.1 Develop an Active Lifestyle
• To promote health, exercise 30 min/day• To achieve and maintain fitness, 29-60 min of continuous activity or
intermittent aerobic activity, 3-5 days/week
Energy Systems, Muscles, and Physical Performance
1. ATP-CP energy system: – Anaerobic: _____________________________– Quick source of ATP
• Cellular ATP and _____________________________
– Fuel for ___________________ of maximal effort
Energy Systems, Muscles, and Physical Performance
2. Lactic acid energy system– “Acceleration stage”– Anaerobic– Breakdown of _________ _____
and _________________________– Rise in __________ triggers muscle
fatigue• How? A rise in acidity impair
breakdown of glucose and inhibits _______ binding _______________ ______________________________
Energy Systems, Muscles, and Physical Performance
3. Oxygen energy system– “Endurance stage”– Breakdown of ____________ and
_______ for energy in the cell’s mitochondria
• Requires oxygen (Aerobic)• Produces ATP more ____________
because the required oxygen has to travel from lungs all the way to the cell’s mitochondria.
Problem Set 11, Q1
• Name the three types of energy system mentioned in class. Classify them into aerobic and anaerobic. How does each of the system acquire energy?
Energy Systems, Muscles, and Physical Performance
• Teamwork in energy production– Anaerobic systems– Aerobic systems
• Glycogen depletion– Steady drop of glycogen
for first _____________– Entirely depleted at
around _____________
Energy Systems, Muscles, Physical Performance
• Endurance training – Training increases number of _____________
improves _____________ enhances aerobic capacity
– Decreases reliance on anaerobic systems– Extends availability of ____________________
Muscles and Muscle Fibers(Problem Set 11, Q2)
• We have two types of skeletal muscles:– Slow-twitch fibers – muscles that develop tension
more slowly; have high oxidative capacities• __________________________ (aerobic endurance)• Ex: __________________________
– Fast-twitch fibers – muscles that can develop high tension rapidly.
• ___________________________________• Ex: ________________________________
– Relative proportion determined by ____________
Figure 11.10 Mix of your Muscle Fibers• If you are best at events requiring explosive movements, you may
have greater percentage of fast-twitch muscle fibers.• If endurance events are your specialty, you may have more slow-
twitch fibers.
Optimal Nutrition for Athletic Performance
• Consume _________________________ (first priority for athletes)– 6-10g/kg per day of carbs– 1.2-1.7g/kg per day of protein– 20-35% of total calories from fat
• Maintain appropriate body weight and body composition
• Promote ___________________ from training• Maintain hydration status
Carbohydrate and Exercise• High-carbohydrate diets:
– Increase ______________– Extend _______________
• Carbohydrate loading– __________ of calories as
carbohydrate– __________ exercise
intensity prior to competition
– Not very beneficial if the aerobic activity lasts less than _______ minutes.
Problem Set 11, Q3a
• Explain what is carbohydrate loading and why it is beneficial to your running.
Carbohydrate intake and Exercise• Before exercise
– Eating carbs 2-4 hours _________ morning exercise helps replenish glycogen stores and improve endurance
– Recommend ________ portions and ___________ foods/beverages
• During exercise– ___________ (______% carbohydrate + ___________)
for events that last at least 1 hour.• After exercise
– Replenish glycogen stores: 1-1.5 grams carbohydrate per body kg both 30 minutes and 2 hours after exercise
Dietary Fat and Exercise
• Fat– Major fuel source for ________________ activities
• Key point: Endurance training increases the capacity of your oxygen energy system, enhancing your body’s ability to use fat as fuel.
– High-fat diet __________ needed– Recommendations:
• Moderate fat intake: 20-35% of calories• Limits saturated fat to less than 10% of energy• Avoid trans fat as much as possible
Protein and Exercise
• Muscles and strength are built with exercise (not extra protein) and carbohydrates provide the fuel needed for muscle-building exercise.
• Protein recommendations– Adults: 0.8 grams per kg body weight– Endurance athletes: 1.2-1.7 g/kg– Resistance-trained athletes: 1.6-1.7 g/kg
• Protein sources– Foods: lean meats, fish, low-fat dairy, and egg
whites
Proteins and Exercise
• Protein intake after exercise:– Protein combined with carbohydrate consumption
after exercising helps replenish _________ more efficiently.
• Dangers of high-protein intake– Diuresis (loss of body water): high protein high
urine production dehydration + mineral losses• High protein diets are neither recommended
nor necessary.
Problem Set 11, Q3b
• Should you still consume dietary fat and protein for your activity? Why or why not?
Vitamins, Minerals, and Athletic Performance
• B vitamins– Needed for ____________ metabolism
• Calcium– Needed for normal _________ function and bones
• Iron– Needed for ___________ delivery and
______________ production– Athletes have _________ losses from trauma to
the capillaries in the feet.
Fluid Needs During Exercise
• Exercise and fluid loss increase risk for dehydration– Increased losses from _____________ (0.5-2.0 L/hour)– Increased with heat, humidity
• Hydration– Adequate fluids ________________________exercise
• Should drink fluid at rates that match sweat rates– Should you drink water vs. sports drinks?
• Depends on duration and intensity of activities• Depends on environmental factors• If >60 min, high humidity, or very intense events, recommend
______________________________________
Characteristics of Nutrition Supplements and Ergogenic Aids
• Ergogenic aids: substances that can ________ athletic performance– Provide calories– Provide vitamins and minerals– Contribute to performance and enhance recovery– Are believed to simulate and maintain muscle
growth
Nutrition Supplements and Ergogenic Aids
• Table 11.10 Types of Ergogenic Aids– Nutritional, Physiological, Psychological,
Biomechanical, Pharmacological
• Regulation and concerns about dietary and herbal supplements– __________ FDA safety and effectiveness
regulations– Possibility of product contamination
Nutrition Supplements and Ergogenic Aids
• Weight-gain powders– Add an extra 500-1000 calories/day
• ________% weight gain by high calorie diet is muscle, rest is fat
– No proof that increasing protein intake above recommended levels improves _______________
– Too much protein ___________________ fat
Nutrition Supplements and Ergogenic Aids and popular theories
• Creatine – _______________________________• Antioxidants – protect muscles/cells from
exercise damage• Caffeine – nerve/muscle signal facilitator, might
increase ability to break down fat for energy• Sodium bicarbonate (baking soda) – to neutralize
_______________• Chromium – ________________________• Iron – for anemia• Green tea extract – weight loss?