The effect of β-alanine and NaHCO3 co-ingestion on buffering capacity and exercise performance with high-intensity exercise in healthy males

Abstract

Introduction: β-alanine (BAl) and NaHCO3 (SB) ingestion may provide performance benefits by enhancing concentrations of their respective physiochemical buffer counterparts, muscle carnosine and blood bicarbonate, counteracting acidosis during intense exercise. This study examined the effect of BAl and SB co-supplementation as an ergogenic strategy during high-intensity exercise.

Methods: Eight healthy males ingested either BAl (4.8 g day(-1) for 4 weeks, increased to 6.4 g day(-1) for 2 weeks) or placebo (Pl) (CaCO3) for 6 weeks, in a crossover design (6-week washout between supplements). After each chronic supplementation period participants performed two trials, each consisting of two intense exercise tests performed over consecutive days. Trials were separated by 1 week and consisted of a repeated sprint ability (RSA) test and cycling capacity test at 110 % Wmax (CCT110 %). Placebo (Pl) or SB (300 mg kgbw(-1)) was ingested prior to exercise in a crossover design to creating four supplement conditions (BAl-Pl, BAl-SB, Pl-Pl, Pl-SB).

Results: Carnosine increased in the gastrocnemius (n = 5) (p = 0.03) and soleus (n = 5) (p = 0.02) following BAl supplementation, and Pl-SB and BAl-SB ingestion elevated blood HCO3 (-) concentrations (p < 0.01). Although buffering capacity was elevated following both BAl and SB ingestion, performance improvement was only observed with BAl-Pl and BAl-SB increasing time to exhaustion of the CCT110 % test 14 and 16 %, respectively, compared to Pl-Pl (p < 0.01).

Conclusion: Supplementation of BAl and SB elevated buffering potential by increasing muscle carnosine and blood bicarbonate levels, respectively. BAl ingestion improved performance during the CCT110 %, with no aggregating effect of SB supplementation (p > 0.05). Performance was not different between treatments during the RSA test.

Fig. 1

Design of the study. Each trial consisted of two exercise tests performed over consecutive days. A total of 12 weeks between trials 2 and 3 was implemented to ensure adequate supplement washout time participants randomised to ingest β-alanine during the initial chronic supplementation. MRS Magnetic resonance spectroscopy, RSA repeated sprint ability test, CCT _110 % cycling capacity test. Solid arrows depict crossover between acute supplementation (Pl and SB). Dotted arrows depict crossover between chronic supplementation (BAl and Pl)

Fig. 2

Changes in carnosine concentration in the gastrocnemius (a) and soleus (b) pre- and post-6-week chronic supplementation of β-alanine (BAl) and placebo (Pl) for n = 5. Values expressed as mean ± SEM. *p < 0.05 from Pl at 6 weeks (post), ^# p < 0.05 from pre-supplementation

Fig. 3

Blood HCO₃ ⁻ (mmol L⁻¹) changes for study groups during the repeated sprint ability (RSA) and cycling capacity test (CCT_110 %). Values expressed as mean ± SEM. *p < 0.05 BAl-SB and Pl-SB from Pl–Pl, ^# p < 0.05 BAl-SB and Pl-SB from PreEx0, ⁺ p < 0.05 Pl-SB from PreEx0, thick vertical bar denotes exercise

Fig. 4

Blood pH recorded for the different groups during the repeated sprint ability (RSA) and cycling capacity test (CCT_110 %). Values expressed as mean ± SEM. *p < 0.05 BAl-SB and Pl-SB from Pl–Pl, ^# p < 0.05 BAl-SB and Pl-SB from PreEx0, ⁺ p < 0.05 BAl-SB from Pl–Pl, thick vertical bar denotes exercise

Fig. 5

Time to exhaustion (TTE) (s) results for the different supplement groups during the cycling capacity test (CCT_110 %). Values expressed as mean ± SEM. *p < 0.05 from Pl–Pl

Fig. 6

Plasma lactate concentration (mmol L⁻¹) for the different supplemental groups during the cycling capacity test (CCT_110 %). Values expressed as mean ± SEM. *p < 0.05 BAl-SB from Pl–Pl. Thick vertical bar denotes exercise