Buffering agents (sodium bicarbonate) (NOT IN EXAM)

Question 1

What is sodium bicarbonate (NaHCO3)?

Answer 1

A blood (extracellular) buffer, which plays an important role in maintaining pH (both extracellular and intracellular).

Question 2

What are the effects of sodium bicarbonate?

Answer 2

Extracellular buffer
(↓ blood and muscle acidosis)

H+ + HCO3 –> H2CO3 –> H2O + CO2
Hydrogen + bicarbonate –> carbonic acid –> water and carbon dioxide

=

↓ fatigue
↑ muscle metabolic function
↑ exercise capacity (anaerobic)

Question 3

For a single-dose strategy, when should you consume?

Answer 3

consume 60 to 180 min before exercise

Smaller, multi-day protocols last 3-7 d and could help minimise side effects (useful if you’re sensitive to side-effects)

Question 4

What is the primary side effect associated with sodium bicarbonate supplementation?

Answer 4

gastrointestinal upset including nausea, stomach pain, diarrhoea and vomiting.

Question 5

How should you supplement?

Answer 5

Acute dose loading protocol
(2-3 h before exercise)
200-300 mg/kg BM sodium bicarbonate
+ 10 mL/kg BM fluid
+ 1.5 g/kg BM CHO
CONSUME SLOWLY! (over 30-60 min)

Question 6

What are alternative dosing strategies?

Answer 6

– split doses (i.e., several smaller doses giving the same total
intake) taken over a time period of 60-180 min.
– serial loading (multi-day) with 3-4 smaller doses per day for
2-4 consecutive days prior to an event

Question 7

When should you consider its use?

Answer 7

• High-intensity events (1-7 min) where
  muscle acidosis causes fatigue e.g., rowing, swimming, middle distance running.
• High-intensity, endurance sports (>1 h)
  where a surge or sprint/climb to the finish may be required.
• Sports involving prolonged repeated high intensity bouts e.g., team sports, racquet and combat sports.
• Can be used to enhance training capacity and training adaptations when training is characterised by any of the above characteristics