Wednesday, December 9, 2015

Creatine and Bicarbonate - A Worthwhile Combination: Supplements Exert Great Individual and Small Combined Effects on HIIT Performance Test in Nine Well-Trained Men

The results of a Wingate test cannot be translated 1:1 to any sports.
You will probably remember my article about the combination of creatine and bicarbonate. Mixing both is basically what the producers of "buffered creatine" supplements do. Albeit with amounts of bicarbonate that may affect the uptake of the latter and offer benefits if you have to load as fast as possible, but won't have individual performance effects (learn more).

Other studies I've likewise covered in the SuppVersity News in the past showed both significant as well as borderline significant and non-significant beneficial effects of combining creatine and bicarbonate for a performance enhancing double-whammy in trained individuals.
You can learn more about bicarbonate and pH-buffers at the SuppVersity

The Hazards of Acidosis

Build Bigger Legs W/ Bicarbonate

HIIT it Hard W/ NaCHO3

Creatine + BA = Perfect Match

Bicarb Buffers Creatine

Bicarbonate Works for Most(!) Athletes
Against that background it is not surprising that a recent study by Griffen et al. (2015) found similarly ambiguous results. The study investigated the effects of creatine and sodium bicarbonate coingestion on mechanical power during repeated sprints. To this ends, nine well-trained men (age = 21.6 ± 0.9 yr, stature = 1.82 ± 0.05 m, body mass = 80.1 ± 12.8 kg) participated in a double-blind, placebo-controlled, counterbalanced, crossover study using six 10-s repeated Wingate tests.

Before each of the performance tests, the participants ingested either a placebo (0.5 g/kg of maltodextrin), 20 g/d of creatine monohydrate + placebo (Cre), 0.3 g/kg of sodium bicarbonate + placebo (Bi), or coingestion  (Cre + Bi) for 7 days, with a 7-day washout between conditions. Participants were randomized into two groups with a differential counterbalanced order. Creatine conditions were ordered first and last. The participants individual mechanical power output (W), total work (J) and fatigue index (W/s) were measured during each test and analyzed using the magnitude of differences between groups in relation to the smallest worthwhile change in performance.
Figure 1: Subject allocation.
Yes, the washout period could be a problem: With only nine participants you have to do crossover study, but in view of the results of previous studies (McKenna. 1999), which report washout times of 4 weeks, the scientists would have been on the safer side if they had planned for a washout of 28, not just 7 days. Now you may argue that not all subjects started "on" creatine, so that the residual effect could average out. The problem, however, is that the significance of the results of a study with only nine participants gets impaired with every subject who was in a creatine group before being randomly assigned to one of the placebo + X groups, so that the researchers would have had to order all the creatine conditions last, not one first and the other last, as it is depicted in Figure 1 and described in the full text of the study.
As the data in Figure 2 tells you, both, the creatine (effect size (ES) = 0.37–0.83) and sodium bicarbonate (ES = 0.22–0.46) supplementation, resulted in meaningful improvements of all three indices of mechanical power output compared to placebo. Now what we are really interested in, though, is what the combination of the two did...
  • In general, the coingestion provided "small meaningful improvements on indices of mechanical power output (W)" (Griffen. 2015) 
  • The previously mentioned advantage was yet only seen when comparing sodium bicarbonate (ES = 0.28–0.41) with the combination treatment; a similar beneficial effect was not seen compared to creatine alone
This does obviously mean that the addition of bicarbonate to creatine did not result in meaningful increases in power output in this particular exercise test.
Figure 2: The only relevant advantage of combining both creatine and bicarbonate was seen for the total work done (orange bars, see orange arrow); this however is also among the most relevant measures for real athletes (Griffin. 2015).
What it did do and that's what we actually take bicarbonate for is to "provided a small meaningful improvement in total work (J; ES = 0.24) compared with creatine" (Griffin. 2015) - or, in other words, anyone who does not just one, but several all-out sprints (and that's almost every athlete) will see a small but meaningful performance increase, one that may make the difference between victory and defeat (see Figure 1, orange bars).
The increase in PGC-1a expression you get if you do HIIT w/ sodium bicarbonate and the correspondingly increased stimulus for mitochondrial biogenenesis is a hitherto often overlooked benefit of "baking soda" supplementation | learn more
Disappointing? I would not say so, which significant improvements in response to both supplements and a potential "game changing" increase in the total work the subjects were able to perform on the cycle ergometer during the repeated Wingate tests, both supplements have proven their efficacy and the potential benefits of combining them. Benefits the Griffin et al rightly call "small", but "meaningful" in the conclusion to their recently published paper.

The fact that these benefits may not be as exorbitant as some of you may have hoped for does not imply that the combination of creatine and bicarbonate supplements is useless. In view of the overall small study size (low number of subjects even for a crossover study), the problem with the washout and the specificity of the exercise - who knows what the results in the gym or on a football field would have looked like, thus, future studies are warranted | Comment!
  • Barber, James J., et al. "Effects of combined creatine and sodium bicarbonate supplementation on repeated sprint performance in trained men." The Journal of Strength & Conditioning Research 27.1 (2013): 252-258.
  • Griffen, C., et al. "Effects of Creatine and Sodium Bicarbonate Co-Ingestion on Multiple Indices of Mechanical Power Output During Repeated Wingate Tests in Trained Men." International Journal of Sport Nutrition and Exercise Metabolism, 2015, 25, 298-306.
  • McKenna, Michael J., et al. "Creatine supplementation increases muscle total creatine but not maximal intermittent exercise performance." Journal of Applied Physiology 87.6 (1999): 2244-2252.