Sodium Bicarbonate + Caffeine: 2x SuppVersity Suggested Ergogenics Strike Again | HIIT Performance ⇈, Decreased Fatigue ↓ W/ Both Ergogenics - Greater Benefits W/ NaHCO3

Don't worry. The study at hand was not intended to test something that occurs only with arm-cranking. The arm-cranking HIIT regimen was simply used to provide a pre-exhausting exercise stimulus before the subsequent Yo-Yo Test. The idea was to provide a maximal metabolic stimulus and to ramp up the H+ production to a similar extent as high intensity high volume workouts.

It has been a while since the last sodium bicarbonate news on the SuppVersity. Luckily, the bicarbonate-free time is over: Matthaus Marriott, Peter Krustrup, and Magni Mohr published a study on the ergogenic effects of caffeine and sodium bicarbonate supplementation on intermittent exercise performance preceded by intense arm cranking exercise in the Journal of the International Society of Sports Nutrition (Marriott. 2015).

As a SuppVersity reader you will know that NaHCO3 (=sodium bicarbonate) ingested 90–150 min prior exercise has been used as an ergogenic aid for athletic events. In that the benefits depend largely on the contribution of anaerobic glycolysis to the individual exercise, since the ergogenic potential that NaHCO3 might elicit is suggested to depend upon the demands of the activity being sufficient to induce performance inhibiting levels of metabolic acidosis (McNaughton. 2008).
And in fact, NaHCO3 ingestion has been reported to improve competitive and laboratory-based protocols lasting 1 –7 min including swimming, middle distance running, rowing and repeated sprinting (Carr. 2011). The aim of the present study was now to compare the effects of caffeine and NaHCO3 supplementation 70–90 min prior to exercise, respectively, on a Yo-Yo Intermittent Recovery test level 2 (Yo-Yo IR2), which consists of 20-m shuttle runs at progressive running speed and has a high anaerobic energy turnover, as well as on the physiological response to intense intermittent exercise with prior metabolic acidosis induced by intense arm cranking exercise.

To this ends, 12 healthy male participants involved in sub-elite team-sports (age: 20.8 ± 1.4 (±SD) yrs.; height: 183 ± 7 cm; body mass: 78.9 ± 5.4 kg) were performed a baseline, control (CON) Yo-Yo IR2
without supplementation or prior arm-exercise and a...

• combined Yo-Yo IR2 + previous arm-craning trial w/ placebo (PLA; plain flour), 
• combined Yo-Yo IR2 + previous arm-craning trial w/ caffeine (CAF), or
• combined Yo-Yo IR2 + previous arm-craning trial w/ sodium bicarbonate (NaHCO3) 

supplementation in a single-blind, randomized, crossover trial in the course of which the participants were were not allowed to consume food items containing caffeine. Moreover, the food intake was noted the day prior to the first test trial and replicated prior to the remaining trials.

"Upon arrival to the laboratory participants were fitted with a heart rate (HR) monitor (Polar Electro, Kempele, Finland) and a baseline fingertip capillary blood sample was obtained. Participants were then given either CAF or PLA (blinded) or NaHCO3 to orally ingest under the supervision of the researchers. 70 min before the start of the Yo-Yo IR2 either CAF or PLA was taken orally in gelatine capsule (6 mg/kg body mass; 474 ± 31 mg). NaHCO3 was ingested orally in 21 –25 gelatine capsules (0.4 g.kg−1 body mass; 31.6 ± 1.6 g) and supplementation began 90 min prior to the start of the Yo-Yo IR2 with 7 ml/kg of water drank ad libitum over a 30 min period as described by Carr et al. (Carr. 2011)." (Marriott. 2015).

The arm exercise protocol lasted for 17 min, during which the participants maintained a constant cadence (80 ± 5 RPM) at individualised power outputs (157.6 ± 7.4 W). The protocol, adapted from others [14,15] consisting of 4x1 -min and 1×1.5-min exercise periods separated by 0.5-min recovery, followed by 4.5 min of recovery and a final 1 -min exercise period. Immediately after completion of the arm exercise, a blood sample was taken.

Figure 1: Blood lactate accumulation and Yo-Yo performance in w/ CAF, NaHCO3 & placebo (Mariott. 2015).

The Yo Yo IR2 began 4 min after the completion of the arm exercise protocol corresponding to 70 min post CAF and PLA intake and 90 min after the NaHCO3 ingestion. The Yo-Yo IR2 test was completed on a wooden surface and consists of repeated two 20-m runs at a progressively increased speed controlled by audio bleeps from a CD player. The test leader controlling the Yo-Yo IR2 test was blinded in relation to drug-treatment.

Figure 2: Effect of supplementation of rate of perveived exertion (RPE | Marriott. 2015).

As the data in Figure 1 reveals, the CAF and NaHCO3 ingestion elicited a 14 and 23% improvement (P < 0.05), respectively, in Yo-Yo IR2 performance, post arm exercise compared to PLA. Furthermore, the NaHCO3 trial displayed higher [blood lactate] (P < 0.05) compared to CAF and PLA (10.5 ± 1.9 vs. 8.8 ± 1.7 and 7.7 ± 2.0 mmol/L, respectively) after the Yo-Yo IR2.

More importantly, however, the NaHCO3 ingestion also lead to significant reductions in the rate of perceived exertion (P < 0.05) during the Yo-Yo IR2 test in comparison to CAF and PLA trial.
References:

• Carr, Amelia J., et al. "Effect of sodium bicarbonate on [HCO3-], pH, and gastrointestinal symptoms." International Journal of Sport Nutrition andExercise Metabolism 21.3 (2011): 189.
• Marriott, Matthaus, Peter Krustrup, and Magni Mohr. "Ergogenic effects of caffeine and sodium bicarbonate supplementation on intermittent exercise performance preceded by intense arm cranking exercise." Journal of the International Society of Sports Nutrition 12.1 (2015): 13.
• McNaughton, Lars R., Jason Siegler, and Adrian Midgley. "Ergogenic effects of sodium bicarbonate." Current sports medicine reports 7.4 (2008): 230-236.