Chapter 11: Nutrition for Physical Activity Flashcards
Physical activity recommendation (18-64)
150 min of moderate physical activity OR 75 minutes of vigorous physical activity per week in bouts of 10 minutes or more;
- increase to 300 min of m or 150 min of v for more benefits and add in 2 muscle strengthening activities per week
define: exercise
planned and structured activity whose goal is to promote fitness
define: sport
planned, structured, competitive activity
define: occupational activity
activity done as part of work
define: leisure activity
activity done as part of leisure
define: active living
a lifestyle that includes multiple chances for physical activity
What does myosin use ATP for?
muscle contractions and body movements can occur
Preferred fuel for physical activity
carbs and lipids
define: aerobic activities
- what type of fuel is used
rhythmic, repetitive, sustained, activities where oxygen delivery matches oxygen needed
- uses glucose, fatty acids, amino acids to produce energy (ATP)
define: anaerobic activities
- what type of fuel is used
- short and/or intense bouts of activities where oxygen delivery cannot match high oxygen need
- can only use glucose for fuel (from anaerobic glycolysis)
First two minutes are anaerobic
- what type of fuel
At moderate intensity after 2 minutes aerobic metabolism dominates
- what type of fuel
First 2 minutes: - ATP (used up in ~2s) - ATP-CP system (usedup in ~10s) - Anaerobic glycolysis (2-2.5min): blood glucose After 2 minutes
At moderate intensity after 2 minutes aerobic metabolism dominates
- Aerobic glycolysis
- Aerobic fatty acid metabolism
What is creatine phosphate and how does it help with fueling anaerobic activity?
Creatine phosphate helps to replenish ATP by donating its phosphate group
Fill in the blank: Glucose is the only dietary fuel that can be used for____ activities. Glucose fuels high intensity activities and the first ____ seconds of exercise
- anaerobic
- 11-120
anerobic metabolism and aerobic metabolism
- exercise examples
- duration
- more likely or less likely to result in fatigue
- formula
Anaerobic metabolism
- Weightlifting, sprinting
- Fuels activities from 20s to ~2 minutes
- More likely to result in fatigue
- Glucose → lactic acid + carbon dioxide + 2 ATP
Aerobic metabolism
- Running, spinning
- Fuels activities for 2 - 20 minutes
- With fatty acid fuels activities for >20 minutes
- Less likely to result in fatigue
- Glucose + oxygen → carbon dioxide + water + 30+ATP
Explain Aerobic Fuel Use Following the First Two Minutes of Exercise
- Glucose use decreases overtime as stores from muscle glycogen and blood glucose deplete
- Lipid metabolism is the main fuel source following the first 20 minutes of exercise (Comes from muscle triglycerides and adipose tissue lipid stores)
Low-moderate intensity activities - aerobic zone
vs High intensity activities - anaerobic zone
- fuel use
- low-moderate: can use all fuels but prefers lipids
- high intensity: can only use glucose and ATP-CP for anaerobic processes
List physiological changes caused by aerobic training (6)
- Increase cell’s capacity to burn fatty acids for ATP
- Heart becomes larger, stronger:
- ↑ cardiac output
- Total blood volume and red blood cell # ↑
- Muscle increases ability to store glycogen
- Number/size of muscle mitochondria increase
What makes the fat burning zone on treadmills misleading?
- While the percent of calories burned from fat is higher in the fat burning zone, you’ll burn more total calories in the cardio zone
define energy availability
energy intake - exercise expenditure; if low, you are more likely to have health issues such as impaired bone health, poor heart health (hypoglycemia, low heart rate)
Nutritional considerations for athletes: carbohydrates
- Used for both anaerobic and aerobic activities
- Consume sufficient carbohydrates to maximize glycogen stores
- low intensity: 3-5g/kg of bodyweight
- moderate (~1 hour per day): 5-7g/kg of bodyweight
- endurance (~1-3hours per day): 6-10g/kg of bodyweight
- extreme (~4-5 hours per day): 8-12g/kg of bodyweight
Nutritional considerations for athletes: protein
- Essential for growth and repair of tissues
- Muscle protein synthesis increases in the 24 hours following exercise
- Recommendation: 0.8kg/ body weight to 1.2-2.0g/kg body weight
Nutritional considerations for athletes: lipids
Do not consume too much before competition (glucose is the preferred fuel source)
Nutritional considerations for athletes: vitamin D and calcium
Bone density
Nutritional considerations for athletes: iron
Heme contribution to hemoglobin for nutrient transportation in blood
Nutritional considerations for athletes: antioxidant
Mitigate muscle damage from exercise
Nutritional considerations for before exercise
- Time and plan pre-workout meals to promote performance and minimize digestive issues
- Pre-exercise meal that contains carbohydrates is best way to maximize time to exhaustion
- Recommendations: 1-4 g/kg body weight of carbs 1-4 hours before exercising for more than 60 minutes
- Favour easily digestible carb sources that are low in fibre and fat
- Favour foods that minimize digestive distress
- Fluid intake is also important
Nutritional considerations for during exercise
- Water is the most important nutrient to consume during exercise
- Electrolytes also need to be replenished for longer bouts of activity
- <1hr of exercise: no extra fuel needed
- > 60+ minutes require extra fuel: 30-60g/hour of easily digested carbohydrates (up to 90g/hour for 2.5+ ultra endurance activity)
Nutritional priorities after exercise (3)
- Promote muscle growth and repair (protein)
- Protein sensitivity is highest in 2 hours following exercise
- Recommendation: 0.25-3 g/kg body weight with 10g of essential amino acid - Refill glycogen stores (carbohydrates)
- Glucose transport into muscle cells increase in 30-40 minutes following exercise - Replenish lost fluids and electrolytes
Define and explain: glycogen supercompensation
- Aka carbo-loading
- Maximizes glycogen stores before a long bout of endurance exercise
- Maximizes time to exhaustion during event
- In two days before an event, consume 10-12g/kg body weight per day
define: ergogenic aids
performance enhancers taken to improve output, muscular gains and/or recovery
creatine
- use
- side effects
- Help maximize muscle creatine stores, providing more fuel for anaerobic activities; enhances muscle mass, glycogen synthesis, and exercise recovery
- side effects: weight gain due to water retention, muscle cramps, gastrointestinal symptoms (diarrhea, abdominal discomfort)
protein supplements
- uses
- Enhance recovery and promote muscle growth and repair; mixed with other nutrients that an athlete may lack in their diet
- Branched chain amino acids also reduce moderate muscle damage
caffeine supplements
- uses
- recommendation
- Psychoactive drug that improves performance through increasing muscular strength, muscular endurance, aerobic endurance, anaerobic power
- Recommendation: 3-6mg/kg body weight and consume in a form without water (coffee and tea cause digestive discomfort)
Hydroxymethylbutyrate
- use
Compound produced by the breakdown of leucine that may improve recovery by decreasing muscular damage (protein breakdown) and increasing protein synthesis
Vitamin and Mineral Supplements
- use for athletes?
Significant performance improvement when you address vitamin or mineral deficiency
anabolic steroids
- use
- side effects
- synthetic compounds that are similar to testosterone; increase muscle mass, strength, and performance
- Side effects: severe acne, increase in risk of tendon issues, aggressive behaviours, cardiovascular risks (increased LDL, decreased HDL, increased blood pressure), mood disorders, schizophrenia related disorders, fertility problems, shrinking testes, decreased testosterone levels
cannabis
- use for athletes
- No known significant improvement to athletic performance
- Negative side effects: chest pain and strength reduction
