Wk 5 Supplements II

Question 1

Beta alanine =

Answer 1

precursor of the dipeptide carnosine

Question 2

Beta alanine: sources

Answer 2

muscle foods (meat, fish, poultry) that contain carnosine or similar beta alanine containing di-peptides.

Question 3

Beta alanine: mechanism

Answer 3

muscular acidosis → reduced force production and increased fatigue → decreased high intensity exercise performance.
Carnosine is responsible for 15% of total buffer capacity.

Question 4

Beta alanine is synthesized from _ and _ by _ _

Answer 4

from histidine and B-alanine by carnosine synthase

Question 5

Beta alanine: demographics

Answer 5

Strongly correlates with type II muscle fiber content. Lower in women, declines with age and lower in veg/vegans. Differences between sports eg sprinters vs marathon runners.

Question 6

Beta alanine: Supplementation

Answer 6

small to moderate performance improvement, 2-3% increases in performance in recreational athletes, 0.5-1% in elite athletes.

Question 7

Carnosine =

Answer 7

a dipeptide that acts as an intra cellular buffer for H+

Question 8

Beta alanine: events + examples

Answer 8

30s-1 min

ex: 200m swim, 4k rowing, 3000m steeplechase

Question 9

Beta alanine: dose

Answer 9

6.4g per day for 4 weeks (split dose), 3.2g/d for remaining 4 weeks.

Question 10

Beta alanine: side effects

Answer 10

temporary paresthesia

Question 11

Caffeine: mechanism

Answer 11

crosses the blood brain barrier - directly affects the CNS. adenosine receptor antagonist - binds to adenosine receptors, speeding up neural activity. Also affects other major neurotransmitters like serotonin for example.
remains in system for 5 hours

Question 12

Caffeine: side effects

Answer 12

positive - improves accuracy, neuromuscular function, cognition, reduces pain perception, short term supramaximal and repeated sprint tasks 3% gains, increases mean and peak power output in anaerobic/1-2 min activities, 1-8% for total work output and repeat sprint performances during intermittent team game activity. Negative - shakiness, anxiety, nausea, poor accuracy, insomnia.

Question 13

Caffeine: supplementation

Answer 13

1-8% improvement in performance

Question 14

Caffeine: events + examples

Answer 14

1 min - hours

achery to tour de france

Question 15

Caffeine: dose

Answer 15

Dose: 3-6mg/kg 45 mins before event, daily limit 400 mgs.

Question 16

Creatine: where to find it?

Answer 16

Synthesized in the liver and kidney from arginine, glycine and methionine; transported to muscle (2-3g per day).

Question 17

Creatine: sources

Answer 17

Diet: meat, fish and poultry (1 g/d in typical omnivorous diet). Intake as a supplement (creatine monohydrate or ethyl ester).

Question 18

Muscle contains _% of body creatine. _ - _% of body pool/d metabolized to creatinine; excreted in urine and resynthesized each day

Answer 18

95%.

1-5% of body pool/d metabolized to creatinine; excreted in urine and resynthesized each day

Question 19

Creatine production: duration + examples

Answer 19

<10-15 sec, ex track or swim sprints

Question 20

Creatine: responders vs non responders

Answer 20

responders are likely those with a lower initial level of total muscle creatine content ie vegetarians, or a greater population of type II fibers.

Question 21

Creatine: supplementation + example events

Answer 21

20-30% increase in skeletal muscle creatine stores. Events: strength power, intermittent high intensity, sprint. Examples: weight lifting, basketball, 400m sprint

Question 22

Creatine: dose

Answer 22

rapid loading; 5g, 4xdaily for 5 days. Slow loading; 3-5g/d for 28 days. Maintenance; 3-5g/day.

Question 23

Creatine: side effects

Answer 23

no effects on liver and kidneys, mild GI upset, 1-2kgs incr in weight due to water retention very common.

Question 24

Sodium bicarbonate: mechanism

Answer 24

Increasing muscle acidity with max exercise results in lacti acid formation, decreasing muscle pH, interfering with muscle contraction. Most important buffers in the blood are hemoglobin, proteins and alkalinizers like sodium bicarbonate (extracellular buffer).

Question 25

Sodium bicarbonate: supplementation

Answer 25

Improvement’ 2% increase in high intensity sprints, dose response relationship - more sodium bicarbonate = observed performance effect.

Question 26

Sodium bicarbonate: events + examples

Answer 26

Events: sustained high intensity exercise performance 1-10 mins. Examples: 1500m running, cycling time trial, speed skating.

Question 27

Sodium bicarbonate: dose

Answer 27

single dose 200-400 mg/kg BM, consumed 1-2 hrs before event. Serial loading with 3-4 smaller doses per day for 2-4 consecutive days prior to an even - very individual.

Question 28

Sodium bicarbonate: side effects

Answer 28

well established GI distress with doses of over 300 mgs/kg.

Question 29

Nitrate: mechanism

Answer 29

increases BF to muscle and phosphate : oxygen ratio = more ATP formed. Reduced ATP cost of muscle force production, promotes mitochondrial biogenesis.

Question 30

Nitrate: performance effect

Answer 30

incr plasma nitrate concentration and decor O2 cost of submax exercise by 1-5%. Improves high intensity exercise tolerance and cycling economy. Enhances 4 and 16 km cycling time trial performance.
NO in elite athletes - no significant diff in power output in an 18 min time trial.

Question 31

Nitrate: performance improvement + events, examples

Answer 31

• 1-3% in TT performance (<40 min events), 3-5% high intensity intermittent team sport (12-40 min).
• Events: medium - long duration, team sports. Examples: hockey, soccer, 10k road race.

Question 32

Nitrate: dose

Answer 32

6-8 mmols of nitrate - 70 ml concentrated shot (beet it sport) 2-3 hrs before an ecent. Possible advantage for elite athletes 3 days before an event $$$.

Question 33

Nitrate: side effects

Answer 33

changes urine color, possible GI upset, reduce resting BP.