Sodium Bicarb Flashcards
(19 cards)
In what sporting scenarios a) event length b) predominant energy pathway c) fatigue experienced does sodium bicarb reliably benefit performance?
For sodium bicarb to have an ergogenic effect on performance activity must be…
a) 1-7 mins long
b) anaerobic glycolysis makes up a substantial contribution to energy requirements
c) metabolic acidosis is the main limiting factor and cause of fatigue (the “burn” is experienced)
In what sporting scenarios does sodium bicarb not reliably benefit performance?
when failure occurs due to the cardiorespiratory system or due to force production by the CNS.
What does supplementation of sodium bicarb increase in the body?
serum levels of bicarbonate (normally produced by the kidneys)
How does anaerobic glycolysis cause fatigue?
formation of lactic acid (lactate + H ions). H ions build up and lower muscle pH (acidosis), interfering w/ muscle contraction process.
What is the mechanism by which sodium bicarb reduces intramuscular acidosis?
Buffers H ions in the blood (as sodium bicarb ions are unable to permeate the sarcolemma).
This raises blood pH creating a gradient and efflux of H ions from muscle, therefore, raising muscle pH and lowering intramuscular acidosis.
How does sodium bicarb benefit performance when anaerobic glycolysis is the main energy pathway?
H ion buffer, reducing muscle fatigue.
Enables athlete to generate more ATP from anaerobic glycolysis before an equivalent level of fatigue is reached.
Power output can be maintained longer.
a) What is the typical magnitude of benefit to various performance measures (e.g. work capacity, TTE etc.)
b) Give a specific study showing the benefits
a) ~2-3% improvement found from a meta-analysis
b) Wilkes et al (1983), 5/6 trained runners significantly improved 800 m time (ave 2.9 s) after consumption of 300 mg/kg of sodium bicarb.
+ves and -ves of acute supplementation?
+ benefits to performance observed
+ cheap
- GI discomfort
- not wonderful support for acute performance enhancement
+ves and -ves of chronic supplementation?
there is a reference in there somewhere
+ strong evidence that it benefits mean and peak power output on wingate test (Lopes-Silva et al, 2019)
+ strong evidence for training adaptations
+ less likely to cause GI stress on comp day
- more expensive way to supplement
What are some areas of future research into sodium bicarb?
> look at elite athletes
> more research into acute vs. chronic to find optimal protocol
What is the optimal acute dosing for sodium bicarb?
200 mg/kg b.w 1-2 hours prior improves performance in most studies.
~300 mg/kg b.w appears optimal w tolerable side effects.
Dose-responsive relationship, but >300 mg/kg b.w is uncomfortable when taken all at once.
What are the negative side effects of sodium bicarb supplementation (large doses)?
> increased blood pressure (due to sodium)
> GI upset, bloating, cramps etc (due to reaction of sodium bicarb w/ HCl in stomach, producing CO2)
How could you alleviate some of the side effects of sodium bicarb?
Stick to reasonable dosing (~200-300 mg/kg b.w)
Hydrate during loading
Split dosage into multiple portions.
How would you obtain sodium bicarb?
Most supermarkets and online.
How may obesity increase your chances of GI discomfort w/ sodium bicarb supplementation?
Dosing is measured w/ reference to bodyweight, therefore, obese individuals may take falsely high oral doses. Calculate instead based on ideal weight.
What are some downsides of the majority of trials observing sodium bicarbonate’s effect on activity?
- reference
> Using mostly untrained individuals, little research into trained/elite, who are most likely to use it.
Only ~3% of trial ppts are female (gender differences?)
Majority of studies observed capacity rather than performance (lower ecological validity).
- Matson (1993) meta-analysis
How could training status of ppts influence findings?
anaerobic training increases total muscular buffering capacity, therefore, ergogenic benefit of augmenting the bicarbonate buffering system would be less in more trained individuals.
How does study methodology (capacity vs performance) influence effect of sodium bicarb?
- reference
- Matson (1993) meta-analysis
Greater effect sizes found in studies observing exercise capacity (TTE) than exercise performance.
While Wilkes 1983 study found a significant effect of sodium bicarb in trained runners, what is a limitation of the study?
Only 6 ppts.
