1. Sports Nutrition
2. What is Fitness?
a. Slide Notes:
i. Cardiorespiratory endurance
ii. Muscular strength
iii. Muscular endurance
iv. Flexibility
b. Cardiorespiratory endurance is what most people think of as fitness – delivery of O2 to
blood and how long you can go for. Muscular strength is the ability to move weight.
Muscular endurance is how many times you can repeat a movement, such as a push-up
or sit-up, before fatigue sets in. Flexibility is the range of motion around a given joint.
Flexibility is an often-forgotten part of a fitness program, despite the fact that it is
important for preventing injuries.
c. Age-adjusted heart rate is just an estimate and that their actual maximum heart rate
may be higher or lower than the age-adjusted one.
3. Why Should I Care?
a. Slide Notes:
i. Increases circulation and strengthens the heart!
1. Increases HDL
2. Lowers resting heart rate
3. Lowers blood pressure
4. Decreases risk of heart disease/stroke
ii. Helps prevent osteoporosis & Type 2 Diabetes
iii. Stress and anxiety decrease
iv. Can enhance self-esteem
v. Helps manage weight and muscle mass
vi. Improves quality of sleep
b. It strenghthens the heart muscle, conditions the heart, and lowers heart rate over all,
reduces weight which reduces work load of the heart.
c. Type 2 diabetes - When exercising, the body needs extra energy or fuel (in the form of
glucose) for the exercising muscles. For short bursts of exercise, such as a quick sprint to
catch the bus, the muscles and the liver can release stores of glucose for fuel. With
continued moderate exercising, however, your muscles take up glucose at almost 20
times the normal rate. This lowers blood sugar levels.
4. Umbrella – no one thing, but exercise can help
5. What is well-balanced exercise?
a. Should include aerobic exercise as well as stretching and strength training
b. Realistic: Consider time and other constraints
6. Be Open-Minded and Consider Your Schedule and Likes
7. Benefits of Strength Training
a. Build muscle mass
b. Increase metabolism (due to increased muscle mass), which goes hand in hand with
c. Controlling weight (due to increased metabolism)
d. Build and maintain bone mass
e. Enhance psychological well-being
f. Prevent injuryImprove daily functioning,
especially in elderly
g. Enhance sport performance
h. Prevent chronic diseases
i. Diabetes
ii. Heart disease
iii. Cancer
iv. High blood pressure
8. Exercise Intensity
a. ACSM – Am. Council Sports Medicine All exercise programs should be designed to meet
the goals of the individual as well as be realistic. The ACSM recommends that to achieve
a cardiovascular benefit, you should exercise at a moderate intensity (55–70% of your
age-predicted maximum heart rate) for twenty to sixty minutes, three to five days per
week. If you exercise at a lower intensity than this, you should exercise longer.
9. Summing Up Fitness Recommendations
a.
10. The Three Paths to Energy
a. ATP – Creatine Phosphate -the pathway you use in the first ten seconds of exercise. It is
the primary pathway used in short-duration maximal efforts, such as power lifting,
kicking a soccer ball, or throwing a shotput. This system uses the very small amount of
ATP stored in the body and does not require oxygen. This is not much fuel, so to go
beyond the ten seconds you will need some other fuel.
b. Anaerobic Glycolysis – As exercise continues beyond ten seconds to about two to three
minutes, glucose is broken down anaerobically through glycolysis. You can produce
energy very fast this way, but not for long. Glucose is broken down to pyruvate, so when
not enough oxygen is available, lactic acid forms. Lactic acid changes the pH in the
muscle, which results in the burning sensation you feel when you run as fast as possible.
Glycolysis is the primary energy system for events lasting two to three minutes, such as
boxing. Only carbohydrates can be broken down anaerobically.
c. Aerobic Metabolism - About two to three minutes into exercise, you begin to use
aerobic metabolism. Fats, carbohydrates, and proteins act as aerobic fuel. Protein will
only be used to a small extent.
11. Graph for Energy
a. It is important to remember that all energy systems are in use at any given time. For
instance, in a very high-intensity activity lasting ten to fifteen seconds, such as the 100-
meter dash, the body will use the aerobic energy system to some extent, even though
most of its energy will come from ATP-PC and anaerobic glycolysis.
12. Getting ATP Back: 1 ATP-CP
a. Creatine Phosphate - unique to muscle fibers. When muscle fibers are relaxed, they
create more ATP than they need for resting metabolism.
i. Special, energy-rich molecule in muscles
ii. Can directly turn ADP back to ATP.
b. Enzyme creatine kinase transfers phosphate group from ATP to creatine, forming
creating phosphate and ADP.
c. Creatine is a small molecule (amino acid-like) that is made in liver, kidneys, and
pancreas, and then transported to muscle fibers.
d. There is way more creatine than ADP is sarcoplams. So when contraction, begins, CK
transfers phosphate from CP back to ADP. Together, CP and ATP provide enough
energy for 15 seconds of contraction.
i. CP gets used up quickly (20 seconds of hard work), ie short meter dash.
e. Creatine is found in red meat, milk, and some fish. Used as performance enhancing
drug. BUT shown to decreases body’s own synthesis of creatine.
13. Getting ATP Back: 2 Anaerobic Glycolysis/Fermentation
a. No O2 needed
b. Good for intense exercise
c. Lactic acid causes pain, though
d. Only good idea for a matter of minutes
e. Pyruvic acid converted to lactic acid
14. Getting ATP Back: 3 Aerobic
a. Happens during rest and aerobic exercise
b. Mitochondrion is used to make LOTS of ATP
c. Take sugar and get the most possible ATP out of it
d. Relatively slow and NEEDS O2
e. Can do it forever as long as have fuel and O2Broken down ONLY in presence of O2
f. Takes ~20-40m of exercise before FAT is used for energy
g. Strength training & aerobic exercise improve the body’s ability to burn fat for energy
15. What Fuels Should I Choose?
a. Carbs - At the start of a workout, the exercising muscles will use their stored
carbohydrates (glycogen). As exercise continues and aerobic metabolism is
predominant, the use of stored glycogen becomes less frequent. At this point, the
amount of glycogen you use depends on how hard you are exercising. Remember, the
higher the intensity, the more you rely on carbs. If you begin exercise with full glycogen
stores, but do not consume any carbs during exercise, your energy will last for sixty to
ninety minutes.
b. Fats- Exercise stimulates enzyme lipase, which promotes the fat burning for energy
i. FAT is the 2nd preferred energy source behind CHO during exercise
ii. Fat has an advantage over carbs as an energy source because it does not run
out, even in the skinniest person. Fat intake should be between 15 and 35
percent.
c. Proteins- Protein rarely provides more than 5 to 10 percent of energy needs, unless
carbohydrate stores are depleted.
i. Protein is needed for muscle growth and repair. Therefore, exercise does
slightly increase the need for protein.
16. Vegetarianism
a. Slide Notes
i. Careful planning
ii. Potential to be neither beneficial nor detrimental
iii. Increased risk for inadequate intake of certain vitamins and minerals (e.g., iron)
b. Vegetarian athletes must plan to consume complementary proteins to ensure adequate
protein consumption. They are also at risk for inadequate iron intake because iron from
plant sources is not as absorbable as that from meat sources. Without enough iron, the
athlete may develop anemia or a marginal deficiency. To avoid this danger, vegetarian
athletes should include vitamin C and an iron supplement in their diet to help absorb
the plant sources of iron. Other nutrients of concern are zinc, B12, vitamin D, and
calcium. These days, vegetarian foods, such as soy milk and veggie burgers, are often
fortified with nutrients to help fight any deficiency.
17. Fluid Balance During Exercise
a. The key to maintaining fluid balance during exercise is to drink early and often. The
amount a person sweats depends on the clothes they wear, the intensity of the
exercise, how trained they are (trained people sweat sooner and may sweat more, but
lose less electrolytes), gender (men have a higher sweat rate than women), and the
weather (heat and humidity).
b. Dehydrating as little as 2 percent may impair performance and may even lead to heat
illness and death.
c. Consume cold beverages if at all possible—cold water empties faster from the stomach
and is absorbed faster. Use an insulated water bottle like the one on this slide, or use a
camel-back hydration pack.
d. Caffeine can enhance performance if taken in the right amount: 1.5–3 mg per pound of
weight; or 220–450 mg for a 150-lb. person; or 10–20 oz. of coffee. The response will be
lessened in those who regularly consume it.
e. Avoid becoming overhydrated (hyponatremia). Don’t replace just water; replace
electrolytes, too.
f. Remember that you still lose fluids when exercising in the cold and will lose more
through breathing. You also may need to insulate water bottles and tubes to keep them
from freezing.
18. How Do Muscles Change When Exercising?
a. We’ve all exercised in various ways
i. Walking, running, playing sports, lifting weights
ii. Sometimes we feel sore during exercise
iii. Sometimes we feel sore afterwards or the next day
b. Aerobic Exercise - As you train your muscle cells get:
i. Better blood supply
ii. More mitochondria (to use that O2 to make ATP)
19. How Do Muscles Change When Exercising?
a. Anaerobic Exercise
i. As you train your muscle cells get
ii. More filaments (Actin & Myosin)
iii. Not really that much growth from new cells
20. DOMS (Delayed Onset Muscle Soreness)
a. Causes not clear
21. Practice Question
a. Describe how our muscles would primarily make ATP during the following activities
i. Holding a heavy weight for 10 seconds
ii. Lifting a very heavy barbell for 2 minutes
iii. Walking slowly around the block
b. How do your muscles change if you 1) train for a marathon, or 2) start lifting weights
every day?