Lecture 7: Non-nutritive Supplements

Question 1

How does the US army get caffeine and why?

Answer 1

Gum, since caffeine is best absorbed via the mouth

Question 2

Which groups should limit their caffeine intake?

Answer 2

• Children (

Question 3

Paradox of caffeine & coffee

Answer 3

Although caffeine decreases insulin sensitivity, long-term coffee drinking decreases risk of T2DM. This is because there are many other compounds in coffee; complex food interactions.

Question 4

Mechanisms: how caffeine increase sport performance

Answer 4

1) Increase fat metabolism (carnitine) to spare glycogen (this glycogen can be used for sprint at the end)
2) Directly affect skeletal muscle – increase excitation-contraction
3) CNS effect; makes you feel good

Question 5

Caffeine increases ENDURANCE performance by…

Answer 5

3% (on average)

Another study found ~14% (not likely)

Question 6

Supplementation protocols for caffeine

Answer 6

• ~6 mL/kg 1 h before exercise (300-500 mg)
• New evidence shows less is also effective
• Doesn’t matter how or when it’s taken, many times have shown to be effective

Question 7

Individual differences in response to caffeine is likely due to…

Answer 7

genetics

Question 8

Detrimental effects of coffee (perhaps)?

Answer 8

Health

• CVD
• Certain cancers

Question 9

Dose of caffeine per day (for no health consequences)

Question 10

Long-term effects of drinking coffee (good for health)

Answer 10

Decreased risk of liver cancer & T2DM

Question 11

Caffeine increases STRENGTH performance by…

Answer 11

~ 4%

Question 12

Supplementation aim

Answer 12

Develop a personalized protocol that is effective for them using the least possible dose

Question 13

Buffers work to prevent…

Answer 13

Acidosis & alkalosis

Question 14

What do buffers do?

Answer 14

Inhibit negative consequences of lactic acid formation

Question 15

How is lactic acid formed? What happens after it’s formed?

Answer 15

Pyruvate + NADH -> Lactic acid + NAD+

Lactic acid -> lactate + H+

Question 16

Is lactic acid bad?

Answer 16

No, the H+ from breakdown is bad. The lactate is not.

Question 17

Why is acid bad for exercise?

Answer 17

1) Inhibits actin-myosin crossbridge formation
2) Inhibits various enzymes
3) Feels uncomfortable, burns

Question 18

Factors affecting lactic acid formation

Answer 18

1) Anaerobic respiration
2) More reliance on glycolysis (untrained person)
3) More use of type 2 fibres (fast-twitch)
4) Clearance of lactate from blood

(efficiency of oxygen use, how circulation distributes oxygen)

Question 19

Two buffer systems we studied

Answer 19

1) Sodium bicarb (oldest)

2) Beta-alanine

Question 20

Where does bicarb naturally exist?

Answer 20

extracellular space

Question 21

How does bicarb works as a buffer?

Answer 21

• increase pH extracellularly

- increase buffering capacity

Question 22

define: buffering capacity

Answer 22

the body’s ability to handle increasing acidic load

Question 23

When is bicarb most effective?

Answer 23

• sports lasing 1-7 min (best evidence)
• sprinting to finish after 30-60 min effort (maybe)
• intermittent-type sports (maybe)

Question 24

AIS: class for bicarb

Answer 24

class A

Question 25

Negative effects of bicarb

Answer 25

GI distress

Question 26

Dose for bicarb

Answer 26

0.3 g/kg taken 2-2.5 h before start of exercise. GI distress may decrease if taken with a meal.

Question 27

Where does B-alaine work?

Answer 27

intracellular

Question 28

Carnosine =

Answer 28

L-histidine + B-alanine protein found inside muscle cells (natural buffer)

Question 29

Why don't we take carnosine? Why take B-alanine instead?

Answer 29

Body can't absorb carnosine. Since B-alanine is the rate-limiting precursor, supplementing with B-alanine will increase carnosine levels.

Question 30

Supplementation of B-alanine / guidelines / how to take it

Answer 30

Need loading phase followed by maintenance phase: - 4 - 6.4 g/day increases carnosine by 60% after 4 weeks (take for at least 4 weeks) - 80% increase after 10 weeks - Divide dose over 0.8 - 1 g servings - Lower doses over longer time have also been effective

Question 31

Which sports is most beneficial if taking B-alanine?

Answer 31

high intensity anaerobic exercise

Question 32

AIS classification of B-alanine

Answer 32

Class A (used to be class B)

Question 33

How does B-alanine make one feel?

Answer 33

Paresthesia: tingly, i-feel-ready feeling

Question 34

Negative effects of B-alanine

Answer 34

Not many studies have been conducted - Does not always work for everyone - No side effects discovered as of yet

Question 35

Once B-alanine is "loaded", how long does buffering capacity last?

Answer 35

6 - 15 weeks (so make sure you take it in advance of most intensive training period)

Question 36

What's special about beetroot juice?

Answer 36

nitric oxide (NO)

Question 37

What is NO?

Answer 37

physiological signalling molecule

Question 38

Functions of NO

Answer 38

- vasodilation* - angiogenesis (blood vessel formation) - regulation of blood pressure - mitochondrial respiration - mitochondrial biogenesis - glucose uptake

Question 39

Synthesis of NO in humans

Answer 39

L-arginine + O2 (in the presence of synthases) -> NO Reduction of nitrate (NO3-) and nitrite (NO2-). These can come from diet!

Question 40

Study outcome: effect of dietary nitrate on oxygen cost during exercise (also, what type of nitrate source was used?)

Answer 40

Took supplemental form of NO3- - 82% increase in plasma nitrite concentration - Reduction of BP - ****Need less oxygen to do sub-maximal exercise (changed VO2Max)!!!

Question 41

What control was used for beetroot juice? What's a better control?

Answer 41

blackcurrant cordial ; | nitrate-free beetroot juice

Question 42

Supplement for nitrate?

Answer 42

beetroot juice

Question 43

Why is beetroot juice > beets?

Answer 43

- more convenient - nitrate content changes depending on how you cook it - need to eat A LOT to get desirable dose

Question 44

How to supplement with nitrate?

Answer 44

- 5-9 mmol of nitrate/day for 1-15 days improves physiological response to exercise - also 2-3 h before exercise

Question 45

Duration of benefit after taking beetroot juice?

Answer 45

5-30 min of continuous max effort exercise