The Latest on Sodium Bicarbonate: Serial Loading Almost as Effective as Acute Loading and Free of Gastrointestinal Side Effects. Plus: Can You Use Potassium Bicarbonate Instead?

NaHCO3 loading has been most successful in events lasting from 1 to 7 minutes (Linderman. 1994) - so either track sprints or volume training
Do you remember my last post on sodium bicarbonate and what I said about the SuppVersity being the place, where you would read about the latest studies on the wonders of baking soda, first? Well, at least I have not seen today's SuppVersity news being covered anywhere else, so I guess for the vast majority I am about to deliver on yet another promise, when I briefly summarizing the latest findings on the "effects of serial and actue NaHCO3 loading in well-trained cyclists" from University of Tasmania and the Tasmanian Institute of Sport in Lanceston, Australia (Driller. 2012; study will be published in the October issue of the Journal of Strength and Conditioning Research).

Why don't we just "load" on NaHCO3 over a longer timespan?

Interestingly, Matthew W. Driller, John R. Gregory, Andrew D. Williams and James W. Fell must have asked themselves a very similar question as I did a couple of weeks ago:  
How come, that there is "limited research describing the use of serial NaHCO3 loading?"
Or put simply: Wouldn't it be likely that we would see similar, in the long haul even superior, results from the chronic ingestion / slow loading of NaHCO3 with less side effects compared to the standard practice of downing 30-50g at once?

Figure 1: The doses on day 1-3 were taken with breakfast, lunch and dinner, the 5 doses on the day of the test (day 5) within 90min before the test; placebo capsules contained microcrystalline cellulose
To answer this question Driller et al. came up with a double-blind placebo controlled, randomized design in which each cyclist underwent 3 experimental trials over a 3-week timeframe:
  • AL - acute NaHCO3 loading
  • SL - serial NaHCO3 loading 
  • P - placebo loading condition 
You can see the "exact" protocol in figure 1 to the right. The main performance variable was a 4-minute cycling test (TT), a choice the scientists explain by referring to it as an approximation (at least duration-wise) of a "complete a 4,000-m individual pursuit in track cycling" and refer to previous research by Lindermann & Gosselink from 1994, which confirms that "NaHCO3 loading has been most successful in events lasting from 1 to 7 minutes" (Driller. 2012).

If you do the math on the figures, you'll see that the respective absolute amounts, i.e. P = 0mg, AL = 0.3mg/kg and SL = 0.9mg/kg were not identical.

You could also argue that the SL group should at least have stuck do their regular protocol on the day of the test, but (1) the higher total dosage in the serial loading trial seems reasonable - after all, your body uses the NaHCO3 also, when you don't work out so you got to build an even greater buffer, and (2) it would have been hard to distinguish the "chronic" from the acute effects if the SL protocol had involved supplementation on the day of the test.

The exercise protocol: A time trial simulates a 4k race

Can I use potassium bicarbonate instead? NO! You can combine both, but from a physiological standpoint it does not makes sense to increase your serum potassium levels before a workout, because especially strength training will leech potassium from the cells into the blood anyways. Moreover your body conserves potassium pretty well during a workout, while you lose a comparably large amount of sodium in your sweat. In other words, you risk offsetting the peculiar balance of the extra-cellular sodium ions and the intracellular potassium ions. While weakness or skeletal muscle hyperexcitability would be rather harmless, but certainly ergolytic consequences, this can - in the worst case - lead to bradycardia (=abnormally slow heartbeats), arrhythmias and even sudden cardiac arrest as it was observed in the two "salt-phobic" bodybuilders in the case report I already cited in the comments on the "Sodium Bicarbonate for High Volume Strength Training" post (cf. John. 2011; there were probably confounding factors at play, here, but still, the risk of developing hyperkalemia is nothing you can totally exclude, if you ingest tons of potassium within a couple of minutes).
If you feel that you don't get enough potassium in your diet, anyway, I'd suggest you mix them at a 3:1 ratio as you usually see it for "normal" sodium and potassium in electrolyte products.
A pros pos "day of the test", on the latter, the participants, 8 well-trained male cyclists (age = 28y; height = 181cm; mass = 73.5 +/- 8.5 kg; VO2peak =66.8 +/- 8.4ml/ kg/min), who were all cyclists currently competing at the state or national level and in their on-season, ingested the placebo or bicarbonate capsules with a tightly controlled amount of water (10 ml /kg body mass) 90 minutes before they hopped onto an air-braked cycling ergometer to perform their time-trial test.
"All the cyclists performed a standardized warm-up before the test, which was replicated before each TT. The warm-up consisted of 3 set intensities relative to the cyclists’ body mass, each lasting 4 minutes. [...] During the exercise test, each cyclist was encouraged to give a maximal effort during the TT. The investigators providing the encouragement were blinded to the trial each cyclist was undertaking. The VO2peak was taken as the highest VO2 value recorded over a 30-second period during the TT." (Driller. 2012)
After the test the cyclists were provided with a modified gastrointestinal side-effects questionnaire which allowed them to quantify the side effects on 10-point Likert scale ranging from 1 = "none" to 10 = "unbearable".

The results: Serial loading with accute effects, but less side effects

Blood samples were taken before and after the trials, the subjects performed in a rested and hydrated state after fasting for at least 2h. They also filled 3-day food and training diaries for the days before the experiment. Since the scientists don't mention those in the FT to the study, I assume there were no significant intrapersonal differences between the trials), so that the results I summarized in figure 2 are not distorted by 3-days of overtraining or 3-days of McDonalds dieting ;-)
Figure 2: Relative power (W/kg), peak blood lactate (mmol/l), HCO3 post loading and post test (mmol/l), pH post loading and post test, VO2 peak (l/min); p < 0.05 for all but the HCO3 post test value - the figures above the bars indicate the percentage of participants which did see practically relevant improvements in the respective parameter (vs. those with improvements that were trivial or even negative; based on Dreher. 2012)
As you can see both the acute, as well as the alternative serial loading protocol yielded the desired improvements in exercise performance. On average, the alkalizing effects, as well as the increases in VO2max were yet more pronounced in the acute compared to the serial loading test... but let's be honest: What's that worth if you get the runs during a race or workout? To be fair, in the study at hand no athlete developed diarrhea, but three felt bloated after the AL protocol, whereas not a single study participant experienced any side effects from the serial loading.

Why not simply stay "on" sodium bicarbonate?

In view of what I have said before about the experimental necessity of not providing any NaHCO3 to the study participants on day 4 of the SL trial, the logical next step in the "evolution of bicarbonate science" would be to probe my previous suggestion to administer the baking soda chronically and keep the study participants "on" NaHCO3 for a week or two during their regular training, without dropping the dose (alternatively even escalating it) on the day of the exercise test / training days.

Figure 3: Latent acidoses can set you up to become obese and prevent your hamper your fat loss (Berkemeyer. 2009)
I would speculate that this would also allow them to exploit the previously cited plethora metabolic benefits of being in a more or less alkaline state (see figure 3 and "How Bicarbonate Could Help You Lose Fat & Build Muscle") and would thus turn something as "profane" as an ergogenic aid into a weight loss and health supplement. This appears even more likely in view of the fact that the study at hand clearly shows that it does not matter whether you use a bicarbonate buffer before your workout, or not, when you're done with it, your HCO3 levels will be rock bottom (assuming that you have trained with maximal intensity). That being said, it appears only prudent not to restrict the use of the buffer to the pre workout window, only, but to use it to re-alkalize your body immediately post workout, as well.

And while I doubt that we will see that study being done in the near future, you know that there is no better place to check for the latest news on sodium bicarbonate, aka baking soda or NaHCO3 than right here, at the SuppVersity ;-)
Update => Dr. Andro's Bicarbonate Protein Pudding: Since Spencer asked me on Facebook how / when I use baking soda and I already betrayed my "secret protein pudding recipe" *lol* I thought I'd post it here, as well.

How it's done: You take some quark (this is a German dairy product you US guys usually know as curd cheese; depending on how hungry you are you use ~100-300g), add water maybe 100ml and stir it, you will soon notice that it does not become a smooth pudding, no matter what you do. So, next you add a scoop of casein or protein powder for the flavor you like best, e.g. chocolate, (casein works best, because it also adds to the creaminess). Mix the protein with the white "soup" and then add 1-2 teaspoons of sodium bicarbonate. You will soon realize that what happens now verifies the term "baking soda": your pudding-to-be is going to start raising like dough, keep the water and some stevia at hand and add water + stevia until the stuff has the consistency and sweetness you like best.  

Voila! Dr. Andro's Quark Based Protein Laden Alkalizing Bicarbonate Pudding is Ready! Makes an excellent last meal of the day, as well... but watch out it is really filling ;-)

References:
  • Berkemeyer S. Acid-base balance and weight gain: are there crucial links via protein and organic acids in understanding obesity? Med Hypotheses. 2009 Sep;73(3):347-56. 
  • Driller MW, Gregory JR, Williams AD, Fell JW. The Effects of Serial and Acute NaHCO3 Loading in Well-Trained Cyclists. J Strength Cond Res. 2012 Oct;26(10):2791-7.
  • John SK, Rangan Y, Block CA, Koff MD. Life-threatening hyperkalemia from nutritional supplements: uncommon or undiagnosed? Am J Emerg Med. 2011 Nov;29(9):1237.e1-2.
  • Linderman, JK,Gosselink, KL. The effects of sodium bicarbonate ingestion on exercise performance. Sports Med 18: 75, 1994.