Summary
Coach Adam Pulford and sports dietitian Kristen Arnold discuss sodium bicarbonate as an ergogenic aid for cycling performance. They cover the mechanism of action — bicarb increases blood alkalinity, helping clear hydrogen ions and delay fatigue during intense efforts — and review the International Olympic Committee's recognition of sodium bicarbonate as one of only four effective supplements for athletes. The conversation covers dosing protocols (0.3g/kg body weight, taken 90 minutes to 3 hours before competition), multi-day loading strategies, and the common GI side effects that have historically limited adoption. They also discuss a new 8-week training study by Gabriella Gallo showing that athletes who supplemented with bicarb during high-intensity sessions saw greater improvements in VO2 max, power at lactate threshold, and time to exhaustion compared to controls. Safety considerations include blood pressure concerns and kidney stone risk, particularly for masters athletes.
Key Points
- Sodium bicarbonate is one of only four supplements recognized by the International Olympic Committee as effective for performance
- Recommended dose: 0.3g per kilogram body weight, taken 90 minutes to 3 hours before competition
- The buffering effect lasts 2-4 hours in the body, making it useful for races with intermittent high-intensity efforts
- Multi-day loading (0.4-0.5g/kg/day for up to 3 days before) can build up blood alkalinity while minimizing race-day GI issues
- An 8-week study showed bicarb supplementation during HIIT training improved VO2 max, lactate threshold power, and time to exhaustion
- GI distress (nausea, diarrhea) is the main barrier — many athletes tolerate it fine, but always test in training first
- Safety concerns: high sodium load (~6,000mg per dose), contraindicated for those with blood pressure issues or kidney stone history
- Best applications: track cycling, criteriums, cyclocross, and any racing with repeated high-intensity efforts
Key Moments
How sodium bicarbonate buffers muscle acidity during intense exercise
Sports dietitian Kristen Arnold explains the mechanism of action: sodium bicarbonate increases blood alkalinity, allowing the body to clear more hydrogen ions and delay the fatigue that comes from acidosis during high-intensity efforts.
"sodium bicarbonate specifically helps to increase the alkalinity or make your blood more basic. So it creates an extracellular environment in which, when we're exercising, a lot of the fatigue we experience is because we're building up hydrogen ions, and so the sodium bicarb, by increasing alkalinity, we can clear out more of those hydrogen ions and therefore delay fatigue."
Dosing protocol and timing for competition
Arnold lays out the evidence-based dosing protocol: 0.3 grams per kilogram body weight, taken 90 minutes to 3 hours before competition, citing both Asker Jeukendrup's research and the 2021 International Society of Sports Nutrition position stand.
"both Dr Jukendrup and this position statement recommend 0.3 grams of sodium bicarbonate per kilogram body weight is shown to be the amount that is effective and also will be less likely to produce side effects."
8-week training study shows bicarb improves VO2 max and threshold power
They discuss a study by Gabriella Gallo showing that athletes who supplemented with sodium bicarbonate during high-intensity training sessions over 8 weeks saw greater improvements in VO2 max, power at lactate threshold, and time to exhaustion compared to the control group.
"they dosed them for the high-intensity workouts themselves. They didn't dose them for the endurance and what they saw was the bicarb group had an increase in VO2 max post eight-week training program power at LT2, which was basically FTP, and an increased time to task failure"
Safety concerns and who should avoid sodium bicarbonate
Arnold flags important safety considerations: the high sodium load (around 6,000mg per dose), contraindication for those with blood pressure issues, and increased risk for athletes predisposed to kidney stones.
"if you have any kind of blood pressure issues, if you're on blood pressure medication, and also something to consider is if you are at a predisposition for kidney stones. A lot of masters, male athletes, are already predisposed and there is some evidence to suggest I mean, it's just a lot of stress on your kidneys putting this much sodium through filtering it."
