Physical Activity - Chapter 10 Flashcards
1
Q
Benefits of Physical Activity (↑ Goes Up)
A
- More restful sleep
- Nutritional Health
- Body Composition
- Bone Density
- Immunity
- Circulation/lung function
- Self-image
- Longer lifespan
- Quality of life
2
Q
Benefits of Physical Activity (↓ Goes Down)
A
- Cancer risk
- Risk CVD
- Type 2 diabetes
- Gallbladder disease
- Anxiety/depression
3
Q
Canada’s Guide to Physical Activity
A
- Adults 18-64 years:
- At least 150 minutes of moderate to vigorous intensity activity per week
- Add up activities in periods of at least 10 minutes
- 2 days per week: muscle and bone strengthening activities
- More physical activity (to a degree) = greater health benefits
- Meeting guidelines can help reduce risk of many chronic
diseases
4
Q
Fuel Use
A
Fuel use depends on intensity and duration
1. At Rest
2. During Activity
3. Anaerobic Activity
4. Aerobic Activity
5
Q
Fuel Use (At Rest)
A
1/2 fatty acids, other ½ mostly glucose, some AAs
6
Q
Fuel Use (During Activity)
A
- Early minutes:
- Majority from muscle
glycogen
- Majority from muscle
- As activity continues:
- Glucose and FAs
7
Q
Fuel Use (Anaerobic Activity - No Oxygen)
A
- Maximal exercise of short
duration (intense activity, e.g., ¼ mile race) - Energy (ATP) from glucose
(glycogen) - Produces lactic acid
- Muscles can use some lactic acid, but when production exceeds use → sent to liver
- Liver enzymes convert back to glucose → sent to
muscles to fuel additional activity - Can accumulate, but does not cause muscle fatigue
8
Q
Fuel Use (Aerobic Activity)
A
- Moderate activity (e.g., jogging)
- Requires oxygen, produces carbon dioxide
- Energy (ATP) from glucose (glycogen) and fat
- Highly trained muscles use less glucose and more fat than untrained muscles, thus, glycogen lasts longer
9
Q
Effect of Diet on Physical Endurance: Carbohydrates
A
- Diet strategies to maintain CHO concentrations
- Eat high CHO diet daily
- High CHO diet enhances athlete’s endurance (ample glycogen stores)
- Take in some glucose during activity
- Eat CHO-rich foods within ~2 hours post activity (boosts muscle glycogen stores)
- CHO loading
10
Q
CHO Loading
A
- Regimen of moderate activity, followed by eating high CHO diet
- Allows muscles to store more glycogen (to nearly double normal muscle storage levels)
- Benefits athletes in long duration activities (>90 minutes)
11
Q
Fats
A
- High fat diets impair performance
1. Too low (<20% kcals)
2. Recommendations
3. Intensity and duration of activity matter
12
Q
Too low (<20% kcals) (FATS)
A
May not take in adequate energy or nutrients
13
Q
Recommendations (FATS)
A
20-30% calories from fat
14
Q
Intensity and duration of activity matter (FATS)
A
- Burn more fat with moderate intensity (aerobic activity)
- At >20 mins duration shift to burn more fat, less glycogen for energy
15
Q
Protein
A
- Eating protein with CHO within 2 hours post activity
- Protein needs
16
Q
Eating protein with CHO within 2 hours post activity
A
- Can enhance muscle protein synthesis
- CHO rich diet spares protein from being used as fuel
17
Q
Protein needs
A
- Higher for both endurance and strength athletes (Table 10-3)
- No benefit beyond 1.6g/kg per day
18
Q
Supplements
A
- Do not enhance performance if well nourished
- Can help if athlete is deficient (deficiencies can impede performance)
19
Q
Vitamin E
A
May protect against exercise induced, oxidative stress; no improvement in performance
20
Q
Iron
A
- Female athletes at special risk for iron deficiency
- Anemia can impair performance (O2 handler)
21
Q
Hot Humid Environments (Fluids)
A
- Fluid loss > 2 litres/hour
- Increased risk of dehydration and heat stroke
(elevated body temp) - Drinking cool water before, during and after physical activity (can absorb ~1 L/hr)
22
Q
Cold Environments (Fluids)
A
- Room temp/warm water to reduce risk of hypothermia
- Electrolytes are replaced by eating a balanced diet afterwards
23
Q
Sports Drinks
A
- Water
- Glucose
- Minerals
- Electrolytes
24
Q
Sports Drinks (Benefits of Glucose)
A
- If activity > 60 mins
- Helps maintain blood glucose
- ~7% sugar; if sugar too high, it delays stomach emptying and intestinal
absorption of water - Sugar may add unwanted calories
25
Q
Sports Drinks (Homemade Recipe)
A
- 1 cup fruit juice
- 2-3 cups water
- 1/3 teaspoon salt (optional)
- Fruit juice and regular soft drinks are too concentrated in sugar, etc.
- Caffeine and alcohol are diuretics
26
Q
Choosing a Performance Diet
A
- Complete Meal Replacers:
- Marketed as “complete” meals, but often fall short
- Calories often from fat and sugars
- Good for athletes with “pre-game jitters” unable to tolerate solid food on day of
event - Should not be used as sole source of nutrients – hard to meet high nutrient needs
- Homemade replacers just as good and cheaper
27
Q
Controversy 10
A
Performance enhancing/ergogenic aids
28
Q
Ergogenic Aids
A
- Products that supposedly enhance performance
- Implies “energy giving”
- Many are regulated under Natural and Non-prescription Health Products in Canada
- Some are banned in Canada
- Some are condemned by the Canadian Center for Ethics and Sports, and are banned by International Olympic Committee
- Most have not been proven to be effective in improving performance, and are unnecessary
- Many have serious side effects
29
Q
Amino Acid Supplements
A
- Consumed for building larger muscles
- Extra AAs do not lead to muscle building
- They are stored as energy after the removal of nitrogen,
increasing nitrogen excretion
- They are stored as energy after the removal of nitrogen,
- AAs compete for absorption
- Such supplements can limit the availability of other AAs
- A well-balanced diet provides sufficient essential AAs to build muscles
30
Q
Caffeine
A
- Endurance athletes may get the benefit of energy boost but provides no advantages
during high-intensity activity- Mechanism of action is not understood, might just be “wake-up” effect
- Anyone exceeding the urinary limit of 12 mg/ml faces a ban leading to disqualification by International Committee of Olympics (5 to 6 cups of coffee within 30 minutes period)
31
Q
Caffeine (Side Effects)
A
- Dehydration
- Stomach upset
- Irritability
- Constriction of arteries causing increased blood pressure causing increased work for the heart
- Could be detrimental to sports performance
32
Q
Caffeine (Common Sources/Products)
A
- Coffee
- Energy drinks
- Guarana
- Carbonated drinks
33
Q
Carnitine
A
- Non-essential nutrient needed by our cells to transport fat molecules
across the mitochondrial membrane- This logic is used to advertise the claim that carnitine increases fat
burning - No evidence that carnitine increases fat burning and energy production
- This logic is used to advertise the claim that carnitine increases fat
- Oral carnitine is not prohibited in international sports
- Body can produce all the carnitine it needs as it is a non-essential
nutrient
34
Q
Creatine
A
- Some scientific evidence exists that creatine enhances performance during intense activity
- Many studies show no such effect
- Creatine metabolism leads to production of the toxin formaldehyde
- Long-term safety is unknown
- May cause kidney damage
- Not illegal in international competitions
35
Q
Hormone Preparations
A
- Anabolic steroid hormones (including steroid alternative supplements)
- Naturally produced by male testes and adrenal glands, and female adrenal glands
- Synthetic forms accelerate muscle growth
- Banned by International Olympics Committee and condemned by The Canadian Centre for Ethics and Sports (CCES) because they give an unfair advantage to the athletes using such products
36
Q
Hormone Preparations (SIDE EFFECTS)
A
- Liver tumors
- Heart disease
- Dramatic increase in aggressive behavior
- Severe depression
37
Q
HumanGrowth Hormone (HGH)
A
- Naturally produced during rest, especially after physical activity
- Synthetic forms lead to abnormal enlargement of organs and bones
- Banned by International Olympics Committee and The Canadian Centre for Ethics and Sports (CCES) because they give an unfair advantage to the athletes using such products
38
Q
Human Growth Hormone - HGH (SIDE EFFECTS)
A
- Diabetes
- Heart diseases
- Thyroid disorders
- Menstrual irregularities
- Increased likelihood of death before the age of 50
