• Biochemistry of buffering capacity and ingestion of buffers in exercise and athletic performance

      Saunders, Bryan; Artioli, Guilherme Giannini; Dolan, Eimear; Jones, Rebecca Louise; Matthews, Joseph; Sale, Craig (Routledge International Handbooks, 2021-01-22)
    • The dose-response to sodium bicarbonate ingestion highlights the need for individuality in supplementation

      Jones, Rebecca Louise; Stellingwerff, Trent; Artioli, Guilherme Giannini; Saunders, Bryan; Cooper, Simon; Sale, Craig; Nottingham Trent University; Canadian Sport Institute; University of São Paulo (Human Kinetics Journal, 2016-10-01)
      To defend against hydrogen cation accumulation and muscle fatigue during exercise, sodium bicarbonate (NaHCO3) ingestion is commonplace. The individualized dose-response relationship between NaHCO3 ingestion and blood biochemistry is unclear. The present study investigated the bicarbonate, pH, base excess and sodium responses to NaHCO3 ingestion. Sixteen healthy males (23 ± 2 years; 78.6 ± 15.1 kg) attended three randomized order-balanced, nonblinded sessions, ingesting a single dose of either 0.1, 0.2 or 0.3 g·kg-1BM of NaHCO3 (Intralabs, UK). Fingertip capillary blood was obtained at baseline and every 10 min for 1 hr, then every 15 min for a further 2 hr. There was a significant main effect of both time and condition for all assessed blood analytes (p ≤ .001). Blood analyte responses were significantly lower following 0.1 g·kg-1BM compared with 0.2 g·kg-1BM; bicarbonate concentrations and base excess were highest following ingestion of 0.3 g·kg-1BM (p ≤ .01). Bicarbonate concentrations and pH significantly increased from baseline following all doses; the higher the dose the greater the increase. Large interindividual variability was shown in the magnitude of the increase in bicarbonate concentrations following each dose (+2.0-5; +5.1-8.1; and +6.0-12.3 mmol·L-1 for 0.1, 0.2 and 0.3 g·kg-1BM) and in the range of time to peak concentrations (30-150; 40-165; and 75-180 min for 0.1, 0.2 and 0.3 g·kg-1BM). The variability in bicarbonate responses was not affected by normalization to body mass. These results challenge current practices relating to NaHCO3 supplementation and clearly show the need for athletes to individualize their ingestion protocol and trial varying dosages before competition.
    • Warm-up intensity does not affect the ergogenic effect of sodium bicarbonate in adult men

      Jones, Rebecca Louise; Stellingwerff, Trent; Artioli, Guilherme Giannini; Saunders, Bryan; Sale, Craig; Swinton, Paul; ; University of Bedfordshire; Canadian Sport Institute–Pacific; University of Victoria; et al. (Human Kinetics, 2021-09-03)
      This study determined the influence of a high (HI) vs. low-intensity (LI) cycling warm-up on blood acid-base responses and exercise capacity following ingestion of sodium bicarbonate (SB; 0.3 g·kg-1 body-mass (BM)) or a placebo (PLA; maltodextrin) 3-hours prior to warm-up. Twelve men (21±2 years, 79.2±3.6 kg BM, maximum power output (Wmax) 318±36 W) completed a familiarisation and four double-blind trials completed in a counterbalanced order: HI warm-up with SB (HISB); HI warm-up with PLA (HIPLA); LI warm-up with SB (LISB); and LI warm-up with PLA (LIPLA). LI warm-up was 15-minutes at 60%Wmax, while the HI warm-up (typical of elites) featured LI followed by 2 x 30-sec (3-minute break) at Wmax, finishing 30-minute prior to a cycling capacity test at 110%Wmax (CCT110%). Blood bicarbonate and lactate were measured throughout. SB supplementation increased blood bicarbonate (+6.4 [95%CI: 5.7 to 7.1 mmol·L-1]) prior to greater reductions with high intensity warm-up (-3.8 [95%CI: -5.8 to -1.8 mmol·L-1]). However, during the 30-minute recovery, blood bicarbonate rebounded and increased in all conditions, with concentrations ~5.3mmol·L-1 greater with SB supplementation (P<0.001). Blood bicarbonate significantly declined during the CCT110% with greater reductions following SB supplementation (-2.4 [95%CI: -3.8 to -0.90 mmol·L-1]). Aligned with these results, SB supplementation increased total work done during the CCT110% (+8.5 [95%CI: 3.6 to 13.4 kJ], ~19% increase) with no significant main effect of warm-up intensity (+0.0 [95%CI: -5.0 to 5.0 kJ). Collectively, the results demonstrate that SB supplementation can improve HI cycling capacity irrespective of prior warm-up intensity, likely due to blood alkalosis.