Chapter 11 Flashcards
Effects of regular exercise
- helps chyme move through GI tract
- promotes Ca deposites in bones
- strengthens heart muscle
Physical activity
part of ADLs
Exercise
physical activity w/ the intent to gain health & fitness benefits
Healthy People 2020 objectives (benefits of fitness)
1) adults should be physically active
2) engage in 150 min of moderate-intensity or 75 min of vigorous aerobic activity, or combination at least 5days/week
3) perform muscle-strengthening activities 2+ days/week
30 min/day of physical activity
(2005 Dietary Guidelines for Americans)
reduce risk of chronic disease
60 min/day of physical activity
(2005 Dietary Guidelines for Americans)
manage body weight and prevent weight gain
90 min/day of physical activity
(2005 Dietary Guidelines for Americans)
sustain weight loss
American College of Sports Medicine (ACSM) Guidelines
Moderately intense cardio 30/day, 5x/week
OR
Vigorously intense cardio 20 min/day, 3x/week
AND
8-10 strength-training exercises, 8-12 reps of each exercise 2x/week
*30 min recommendation is for the average healthy adult to maintain health and reduce risk for chronic disease
Characteristics of a good fitness program
Mode (aerobic, resistance, and flexibility), Duration, Frequency, Intensity, Progression, Consistency, Variety
Mode
type of exercise (large muscle groups continuously working, usually rhythmic in nature) - heart & lungs work harder Aerobic - run/swim Resistance - weights Flexibility - stretch, yoga
Duration
length of exercise (time)
Frequency
how many times exercised in a given week
Intensity
level of effort required during exercise
Progression
how frequency, duration, & intensity advance with exercise
Consistency
continuity of exercise
Variety
variety in workouts
ex: run different routes, etc.
Achievement & Maintenance of Fitness (2 main activities in successful starting)
1) Discuss fitness goals w/ a health care provider
2) Assess and record baseline fitness scores - for benchmarks
Energy sources for muscle use
ATP - immediate usable energy
Phosphocreatine (PCr) - initial resupply of muscle ATP (only in initial 10 seconds
ATP
Immediate usable energy
- lasts 2-4 seconds
- created from multiple sources
Phosphocreatine (PCr)
Initial resupply of muscle ATP (only in initial 10 seconds)
- when ADP accumulates in contracting muscle. Pi is transferred from PCr to ADP - reforms ATP from ADP
- PCr alone can supple Pi for ATP energy for ~ 10 secs
- can ve activated instantly
- replenish ATP for quick bursts
- minimally made & stored
Carbohydrate energy use?
Major fuel for short-term, high-intensity, and medium-term exercise
Anaerobic pathway
NO O2
- intense activity; pyruvate accumulates in muscle - to lactate - 2 net ATP
- fastest way to supply ATP to muscle other than PCr
- ATP source short lived - gycolysis provides energy & creates fatigue
- acidity of muscles increases - slows ATP production & creates fatigue; Potassium is lost
Aerobic pathway
- ATP is slower but greater - 6 net ATP
- can be sustained for hours (2-3h or more)
Muscle glycogen
(350g stored) fuels muscle cells
-important in short-term exercise (<30min)
Liver glycogen
(100g stored) maintains blood glucose
-provides fuel for muscle cells in longer-term exercise
Depletion of glycogen stores:
in muscles: fatigue
in liver: hypoglycemia
in both: “hitting the wall”
Fat energy use?
Main fuel for prolonged low-intensity exercise
- provides more energy than CHO, but is less efficient
- the more trained a muscle is - the greater the muscles ability to use fat as an energy source
increased glycogen storage (in fat)
- increased TG storage (spares glycogen)
- increases size and number of mitochondria & the levels of enzymes assoc w/ aerobic synthesis of ATP
- increases myoglobin - enhances oxygen availability
Ergogenic Aids
- useful in some circumstances (creatine, sodium bicarbonate, and caffeine)
- possibly useful, still under study (HMB, glucosamine, branched chain amino acids, glutamine)
- Dangerous or illegal (anabolic steroids, growth hormones, blood doping, GHB)
Permissible by the National Collegiate Athlete Association Committee on Competitive safeguards and medical Aspects of Sports
- Vitamins and minerals
- energy bars (no more than 30% protein)
- sports drinks
- meal replacements (Ensure Plus)
NOT permissible by the National Collegiate Athlete Association Committee on Competitive safeguards and medical Aspects of Sports
- amino acids
- creatine
- glycerol
- Beta-hydroxy-beta methyl butryric acid (HMB)
- L-carnitine
- protein powder
Protein energy use?
A minor fuel source during exercise (5%)
- more in endurance exercise (up to 15%) as glycogen stores become deleted
- protein is used least in resistance exercise (weight lifting) - as an energy source
- eating more protein than the body needs will not increase muscle mass
Where does protein come from?
the branched chain amino acids - directly or via gluconeogenesis
What increases muscle mass?
1) working the muscles through exercise
2) eating protein supplies the necessary A.A. for the muscle to rebuild itself after being broken down in the workout
Athletes should have how many carb needs?
7-10g/kg body weight (non athletes 5-7g/kg)
Dietary advice for athletes, what should they boost?
boost glycogen stores (carb loading)
Fat needs for athletes are?
15-25% of kcal—mostly unsaturated
Protein needs for athletes are?
1.2-1.7g/kg body weight.
stregnth trained and moderate to high intense athletes; once desired mucles mass is achieves 1.2 g/kg body weight is enough.
Vitamin and Mineral needs for athletes?
iron deficiency and imparied performance
calcium and the female triad.
Fluids lost through sweat and respiration need to
be replaced.
Fluid needs for athletes are caused by
dehydration, heat exhaustion, heat cramps and heat stroke (body higher than 104 degrees)
Fluid intake for athletes the goal
is to lose NO more than 2% of body weight.
What is a late sign of dehydration?
THIRST
Hyponatremia is
water intoxication. too much water.
Sports drinks
carbs and electrolytes
Pre exercise meals
high carb, low fat
fueling during exercise
car replenishment for events longer than 60 minutes
recovery meals
2 hours and 30 minutes after exercise. 1-2g carb per kg/body weight.
