Serial Loading: Stomach NaHCO3 and Benefit from Baking Soda's Performance-Boosting Effect - 3×3g/Meal for 3 Days

You can sure get the cheap stuff from the supermarket, but if you realize it's working for you, buying several kg in bulk costs hardly more than the packets on containers you will find in the baking section of your local grocery store.

For SuppVersity veterans, it's no news that you can take your 0.3-0.5g/kg body weight of baking soda, i.e. NaHCO3 or sodium bicarbonate, spread across three days before an event and still see enormous benefits. I discussed this strategy and corresponding evidence in form of a study in trained cyclists as early as in 2012 (My, that's more than 5 years ago... reminds me that I have been doing this for quite some time, now ;-).

In the meantime, I have repeatedly addressed the performance enhancing (and health) effects of bicarbonate, but ... and that's relevant for those of you who cannot stomach large(r) quantities of baking soda... 99% of the newer studies on performance are conducted with acute sodium bicarbonate dosing in the previously mentioned range of 0.3-0.5g/kg. If you weigh 75kg that's the whopping amount of 37,5 grams of pure baking soda consumed within (usually) 60 minutes before a workout - you better make sure that this doesn't give you the runs (which is, unfortunately, not exactly unlikely) before doing that during competitions.
Serial loading may offer a way out of the diarrhea risk trap. Unlike in the previously cited 2012 study by Driller et al., the international research team (UK, AUS, ESP) who conducted the most recent serial loading study, studied the effects of bicarbonate serial loading in fifteen female university basketball players (23.3±3.4 years; 173.1±5.8 cm; 65.8±6.3 kg; 23.6±4.9% body fat).

Figure 1: Illustration of supplementation and exercise test (Delextrat 2018).

The participants ingested 0.4 g·kg-1 of body mass of sodium bicarbonate or placebo for 3 days (split into 3 equal daily doses), before completing a simulated basketball exercise. The scientists elaborate on that stating that they used the same stuff you may be using when you're trying to avoid drinking the bicarbonate: they bought gelatin capsules (MyProtein gelatin caps, Cheshire, UK) and filled them with either NaHCO3 (Dr Oetker, Leyland, UK) or calcium carbonate (Sigma-Aldrich Co) and explain that they deliberately increased the minimum dosage for acute supplementation (0.3g/kg), significantly, i.e. to 0.4g/kg (not per day, but rather altogether). They also explain:

"Indeed, it has been recommended to use higher quantities than the 0.3 g/kg body mass commonly administered, while serial loading avoids the GI disturbances usually reported with such doses ingested acutely (Burke & Pyne, 2007 | free full-text on researchgate). In addition, capsules were preferred to powder to mask the taste of the substances ingested and allow blinding of the participants to the experimental conditions" (Delxtrat 2018).

Now what's really interesting is that the scientists advised their subjects to consume the capsules not just spread across three days, but also in three equal amounts throughout the day (during breakfast, lunch, and dinner), with the last ingestion at 7pm on the day before the test.
During the supplementation period, participants also reported any gastrointestinal (GI) side effects on a 10-point Likert scale; sprint and circuit times, jump heights, performance decrements and gastrointestinal (GI) side effects were recorded during the test and blood lactate concentration was measured pre- and post-test.

Effects of 3-day bicarbonate loading on performance markers during a simulated basketball game (Delxtrat 2018).

As you can see in Figure 2 the regimen worked like a charm. With significant improvements in mean sprint time (s), mean circuit time (s), mean jump height (cm), ideal sprint time (s), total sprint time (s), and a sign. reduction in sprint performance decrement, the scientists recorded potentially game-changing (literally) performance increments.

So, NaHCO3 serial loading can increase performance, but what about GI stress? 

At least for those of you who have been avoiding bicarbonate supplementation because it gives you the runs, Anne Delextrat et al. have good news. The risk of diarrhea or other GI side effects was, after all, not just reduced - there were simply no side effects (at least none that weren't observed with the placebo supplement, as well).
References:

• Burke, Louise M., and David B. Pyne. "Bicarbonate loading to enhance training and competitive performance." International Journal of Sports Physiology and Performance 2.1 (2007): 93-97.
• Delextrat, Anne, et al. "Effects of 3-Day Serial Sodium Bicarbonate Loading on Performance and Physiological Parameters During a Simulated Basketball Test in Female University Players." International Journal of Sport Nutrition and Exercise Metabolism (2018): 1-20.
• Luft, Friedrich C., et al. "Sodium bicarbonate and sodium chloride: effects on blood pressure and electrolyte homeostasis in normal and hypertensive man." Journal of hypertension 8.7 (1990): 663-670.