Sodium bicarbonate – plain old baking powder – isn't just an interesting a supplement for endurance athletes. According to sports scientists at the University of Southern Mississippi, bodybuilders manage more reps after taking a hefty dose of sodium bicarbonate.
Sodium bicarbonate, a compound that occurs naturally in our blood, has a buffer effect. This effects helps performance when muscle cells are subjected to intense activity and acidify. Sodium bicarbonate can neutralise the acid released to a certain extent, and is therefore an effective endurance sports supplement.
One reason that there aren't more people taking sodium bicarb is the dose. It's so high that frequent use is bound to lead to stomach problems. [And to sodium poisoning? Critical note from the editor.] Should you be thinking of experimenting with sodium bicarbonate, make sure you read up on the subject first, so you know exactly what you can and can't do.
The Americans were curious whether sodium bicarbonate could also help strength athletes. Studies done in the 1990s suggest it doesn't. [Med Sci Sports Exerc. 1993 Aug; 25(8): 960-5.] [Med Sci Sports Exerc. 1998 Apr; 30(4): 523-8.] But, the Americans say, the subjects in these studies had a lower training volume than the average bodybuilder.
For their experiment the American researchers used 12 male students, average age 20, who had been doing weight training for at least two years. The students had to train their legs by doing 4 sets of squats, 4 sets of leg presses and 4 sets of leg extensions. They used a weight with which they would be able to do 10-12 reps, and rested for 90 seconds between their sets.
On one occasion the students were given a placebo and on the other they were given sodium bicarbonate. They were given 0.3 g sodium bicarb per kilogram bodyweight, so a student weighing 80 kg took 24 g of the substance.
The students divided this huge dose over four intakes, with a 10-minute pause between each. They washed the capsules down with 1.6 litres of Gatorade and ate a bread roll to keep their stomach quiet. The sodium bicarb administration started 80 minutes before the students started their workout.
Supplementation increased the training volume of the whole workout by a total of four percent. SQ = squat; LP = leg-press, KE = leg-extensions.
The table above shows that sodium bicarbonate supplementation causes the pH to decrease less – so makes the blood less acid. The extra molecules of sodium bicarb in the blood neutralise the hydrogen atoms released by the muscle cells into the blood, and therefore enable the muscle cells to contract for longer.
"Sodium bicarbonate administration in the present study significantly improved total accumulated repetitions during a lower-body hypertrophy-type resistance exercise regimen", the researchers write. Whether the higher training volume actually meant the strength athletes progressed more, they don't know. It's possible that the acidification, which takes place during strength training and is blocked by sodium bicarbonate, is actually essential for progression to take place.
"For supplementation of this nature to be practical for real-world use in conjunction with hypertrophy-type resistance exercise, the enhanced exercise performance must translate into enhanced training adaptations", the researchers continue. "As there have been no reported investigations into the effects of sodium bicarbonate administration on chronic resistance training, future studies should examine the impact of sodium bicarbonate on the training adaptations associated with hypertrophy-type resistance exercise."
Eur J Appl Physiol. 2013 Mar;113(3):743-52.