Bicarbonate + Beta-Alanine Supplementation, HIT Exercise Performance and Energy Substrates in 71 Trained Cyclists

If there's one take-home message from the study at hand, it is: While both SB& BA work, it depends on the sport/exercise test if the effects will be significant.

If you've been following my articles at the SuppVersity for some time, you will know that I have covered beta-alanine and sodium bicarbonate, two of the few ergogenic supplements for which we have enough evidence to assume that they actually work, extensively in the past.

You will yet also remember that the synergistic effects you'd expect to see when you combine intra- (beta alanine) and extra-cellular (sodium bicarbonate) H+ buffers didn't show in every pertinent study in the SuppVersity archive.

Danaher, et al. (2014), for example, found no effect of combining both during performance test with fixed intensity and volume, while Tobias et al. (2013), whose study tested upper body performance and didn't limit either intensity or volume, did - it almost doubled the total work the subjects performed. Why's that important? Well, if you look at the study design of the latest bicarb + beta-alanine (BB) study by scientists from the University of Sao Paulo (da Silva 2018) you will find that both the training intensity and the total volume were capped. Therefore, it is not totally surprising that the performance benefits didn't reach statistical significance (there were benefits, though).
This doesn't mean, however, that the study wasn't worth looking at. After all, the scientists had their reasons to standardize the workload - without this standardization da Silva et al. wouldn't have been able to achieve their aim to conduct the first study that would investigate the energy metabolism during high-intensity exercise and cycling time-trial performance objectively - and that's only possible if you use work-matched tests that guarantee that one group won't exercise 10 minutes longer or at 10% higher work rates than the other. But let's (re-)address that later and take a closer look at the other key parameters of what I feel is a well-designed, interesting and eventually highly educative study - despite and/or because of the lack of significant performance differences:

• If you develop digestive issues like "the runs" whenever you try to use sodium bicarbonate aka baking soda (NaHCO3), try to "serial load" it | learn here how that works.

  The subjects in da Silva 2018 were 72 trained cyclists(5 ± 4 years of experience in cycling, 9 ± 3 h of training/week, consisting of 235 ± 92 km/week) with a VO2max of 59-60 ml/kg/min that shows that they were real athletes (What's a high VO2max?). 
• Beta-alanine was preloaded for a month at a comparatively high dose (28 days at 6.4g/d; two capsules were ingested four times daily vs. maltodextrin (error in abstract) placebo).
• The 0.3g/kg body weight of sodium bicarbonate (or calcium carbonate placebo) was supplemented within max. 5 minutes 60 minutes before the performance test in 1-g gelatin capsules under supervision to ensure full compliance. Gastrointestinal discomfort was reported prior to and 60 min using a 10-point scale - serial loading protocol as I've described it in previous articles about the bicarb was not used.
• The food intake during the supplementation period was 'monitored' via 3-day food diaries the subjects had to fill on 2 non-consecutive weekdays and 1 weekend day. The analyses of these food logs showed that the subjects consumed ~2200kcal/d with approximately 52%, 18.5%, and 26.5% of the energy coming from carbs, protein, and fats, respectively - without inter-group differences.

The actual testing sessions that were conducted after pre-test and familiarization sessions consisted of a high-intensity intermittent cycling protocol (4x 60s at 110% of the subjects' individual maximal power-output with 60s rests between bouts) that was followed by a 30-kJ time-trial performance test. Both tests performed twice - once before and once after the 28 days of beta-alanine or placebo supplementation (compare the illustration of the study design and main trials in Figure 1).

Figure 1: Experimental design (upper panel) and overview of the main trials (lower panel). BA β-alanine, SB sodium bicarbonate, PL placebo, CaCO3 placebo for sodium bicarbonate, lac plasma lactate analysis, gas blood gas analysis, HICT-110% high-intensity cycling test performed at 110% of Wmax (da Silva 2018)

As it is necessary for any double-blind, parallel-group, placebo-controlled trial, the participants were randomly allocated to the BA (β-alanine + placebo; n = 20, 3 drop-outs), SB (placebo + sodium bicarbonate; n = 20, 3 drop-outs), BASB (β-alanine + sodium bicarbonate; n = 20, 1 drop-out), or PLA (placebo + placebo; n = 20, 2 drop-outs) groups and asked to identify their group allocation (i.e., BA or maltodextrin and SB or calcium carbonate) to verify the blinding process.
Maltodextrin (the abstract falsely claims it was dextrose, which would be a very bad placebo due to its characteristic taste) and calcium carbonate were the placebos for BA and SB. Moreover, the randomisation was performed in blocks of 4 with groups being matched for time to complete a 30-kJ test to avoid significant baseline performance differences between the groups. And finally, blood was sampled before and in-between exercise bouts and the time trial, respectively, and the VO2 consumption measured continuously before and during the HICT110% test.

Figure 2: Effects of β-alanine (BA) and sodium bicarbonate (SB) on the time to complete 30-kJ time-trial performance. The grey bar on c represents the 95% confidence interval of the coefficient of variation of the test. Positive and negative confidence intervals crossing zero on d were deemed nonsignificant (da Silva 2018).

Now, as previously announced, da Silva et al. did not find a significant effect of any of the three supplementation protocols on the subjects exercise performance. Both, Figure 2 (c) & (d) do yet suggest non-significant performance improvements - with the largest effect size being and a borderline significant effect being observed in the BA + SB group.

Measurable effects, but no significant performance increases - so what?

As previously hinted at, these results are not completely surprising, because the ergogenic effects of H+ buffers, in general, and bicarbonate in particular, critically depends on the build-up of sufficient amounts of H+ to be buffered. Within the very short (~60s) bouts of exercise that was aborted when the subjects hit the 30-kJ mark this requirement probably wasn't met - or, in view of the non-significant benefits, it was at least not met to a sufficient degree.

Figure 3: The amelioration of the decline in blood pH and bicarbonate shows that the SB treatment did what it was supposed to do - work as a buffer. However, as Figure 2 shows, the differences in pH and blood HCO3 were obviously too small to make a significant difference during the very short 30kJ performance test (da Silva 2018).

As Figure 3 shows, this doesn't mean that the buffers didn't work (SB successfully buffered the decrease in blood pH and we can assume that a muscle biopsy would have shown slightly reduced intra-cellular H+ levels due to BA). It just means that the biochemical differences to the control trial were too small and the inter-group variance too large to detect significant performance benefits.
The same must be assumed of the lactate buffering effects of SB. In the scientists' multiple comparison analysis of the post-HICT-110% plasma lactate levels in the SB group, the latter approached significance (t = − 1.82, p = 0.074), and were significantly higher after the 30-kJ TT in both, the SB only (t = − 2.67, p = 0.01) and the BASB group (t = − 2.61, p = 0.011).

Figure 4: Effects of β-alanine (BA) and sodium bicarbonate (SB) supplementation on the absolute contribution of the energy systems during the HCT-110% test (da Silva 2018). The increase glycolytic flux and improved ability to tap into the readily available glucose sources can be ascribed to the pH buffering effect of SB (Sutton 1981).

Unfortunately, lactate still has an unwarrantedly bad rep (Cairns 2006). It is thus important to note that increased lactate levels are a necessary consequence of an increased use of glucose and by no means a reason to expect performance decrements. In fact, almost all SB studies which tested the level of lactate in the subjects' blood found it to be significantly increased in the presence of significant performance benefits! That's something people tend to forget in a day and age where even the superiority of glucose as the #1 substrate for high-intensity exercise is questioned (sorry keto fans, but that's simply what the contemporary evidence says - keto-adapted or not ;-).
References:

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• da Silva, Rafael Pires, et al. "Effects of β-alanine and sodium bicarbonate supplementation on the estimated energy system contribution during high-intensity intermittent exercise." Amino Acids (2018): 1-14.
• Danaher, Jessica et al. "The effect of β-alanine and NaHCO3co-ingestion on buffering capacity and exercise performance with high-intensity exercise in healthy males." Eur J Appl Physiol (2014) 114:1715–1724.
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• Sutton, J. R., N. L. Jones, and C. J. Toews. "Effect of pH on muscle glycolysis during exercise." Clinical science 61.3 (1981): 331-338.
• Tallon, Mark J., et al. "The carnosine content of vastus lateralis is elevated in resistance-trained bodybuilders." Journal of Strength and Conditioning Research 19.4 (2005): 725.
• Tobias, Gabriel, et al. "Additive effects of beta-alanine and sodium bicarbonate on upper-body intermittent performance." Amino acids 45.2 (2013): 309-317.