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
Sports Drinks (Homemade Recipe)
- 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
Choosing a Performance Diet
- 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
Controversy 10
Performance enhancing/ergogenic aids
28
Ergogenic Aids
- 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
Amino Acid Supplements
- 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
- 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
Caffeine
- 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
Caffeine (Side Effects)
- Dehydration
- Stomach upset
- Irritability
- Constriction of arteries causing increased blood pressure causing increased work for the heart
- Could be detrimental to sports performance
32
Caffeine (Common Sources/Products)
- Coffee
- Energy drinks
- Guarana
- Carbonated drinks
33
Carnitine
- 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
- Oral carnitine is not prohibited in international sports
- Body can produce all the carnitine it needs as it is a non-essential
nutrient
34
Creatine
- 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
Hormone Preparations
- 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
Hormone Preparations (SIDE EFFECTS)
- Liver tumors
- Heart disease
- Dramatic increase in aggressive behavior
- Severe depression
37
HumanGrowth Hormone (HGH)
- 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
Human Growth Hormone - HGH (SIDE EFFECTS)
- Diabetes
- Heart diseases
- Thyroid disorders
- Menstrual irregularities
- Increased likelihood of death before the age of 50
