Sodium Bicarbonate Ingestion Improves Time-to-Exhaustion Cycling Performance and Alters Estimated Energy System Contribution: A Dose-Response Investigation

Abstract

This study investigated the effects of two sodium bicarbonate (NaHCO 3) doses on estimated energy system contribution and performance during an intermittent high-intensity cycling test (HICT), and time-to-exhaustion (TTE) exercise. Twelve healthy males (stature: 1.75 ± 0.08 m; body mass: 67.5 ± 6.3 kg; age: 21.0 ± 1.4 years; maximal oxygen consumption: 45.1 ± 7.0 ml.kg.min −1) attended four separate laboratory visits. Maximal aerobic power (MAP) was identified from an incremental exercise test. During the three experimental visits, participants ingested either 0.2 g.kg −1 BM NaHCO 3 (SBC2), 0.3 g.kg −1 BM NaHCO 3 (SBC3), or 0.07 g.kg −1 BM sodium chloride (placebo; PLA) at 60 min pre-exercise. The HICT involved 3 × 60 s cycling bouts (90, 95, 100% MAP) interspersed with 90 s recovery, followed by TTE cycling at 105% MAP. Blood lactate was measured after each cycling bout to calculate estimates for glycolytic contribution to exercise. Gastrointestinal (GI) upset was quantified at baseline, 30 and 60 min post-ingestion, and 5 min post-exercise. Cycling TTE increased for SBC2 (+20.2 s; p = 0.045) and SBC3 (+31.9 s; p = 0.004) compared to PLA. Glycolytic contribution increased, albeit non-significantly, during the TTE protocol for SBC2 (+7.77 kJ; p = 0.10) and SBC3 (+7.95 kJ; p = 0.07) compared to PLA. GI upset was exacerbated postexercise after SBC3 for nausea compared to SBC2 and PLA (p < 0.05), whilst SBC2 was not significantly different to PLA for any symptom (p > 0.05). Both NaHCO 3 doses enhanced cycling performance and glycolytic contribution, however, higher doses may maximize ergogenic benefits.

Effects of post-exercise sodium bicarbonate ingestion on acid-base balance recovery and time-to-exhaustion running performance: a randomised crossover trial in recreational athletes

“…Post-exercise NaHCO3 ingestion elevated W[LA] energy contribution during subsequent exercise, which agrees with previous pre-exercise ingestion findings (Gurton et al, 2020;da Silva et al, 2019) and offers additional mechanistical insight to explain changes in TTE performance. Despite the limited recovery period, an acute NaHCO3 dose induced a sufficient change in alkalotic state to augment total glycolytic flux during TTE2, which was likely caused by up-regulated lactate-H + cotransport from intramuscular environments via the monocarboxylate transporter (Messonnier et al, 2007).…”

“…On arrival to the laboratory during experimental trial visits, participants completed visual analog scales for gastrointestinal (GI) discomfort (0 mm = "no symptom at all"; 100 mm = "severest symptom imaginable") to quantify perceived severity of flatulence, abdominal discomfort (AD), gut fullness (GF), bowel urgency rating (BUR) and diarrhoea (Gough et al, 2017a;Gurton et al, 2020).…”

“…This approach provides reliable and valid estimations for WAER during high-intensity exercise (da Silva et al, 2019;Milioni et al, 2017). Glycolytic (W[LA]) was calculated from delta blood lactate (ΔBLa -) during TTE protocols, according to the assumption that a difference of 1 mmol.l -1 of BLacorresponded to 3 ml.kg -1 BM of O2 (Milioni et al, 2017;Brisola et al, 2015;Gurton et al, 2020), by using the following equation: W[LA] = ΔBLax 3 x body mass (kg).…”

“…This alkalotic state may also increase glycolytic activation by preventing the allosteric inhibition of enzymes such as glycogen phosphorlyase and phosphofructokinase (Messonnier et al, 2007). Pre-exercise NaHCO3 ingestion has been demonstrated to augment glycolytic flux during high-intensity exercise protocols (da Silva et al, 2019;Gurton et al, 2020). The effect of a post-exercise NaHCO3 supplementation strategy on energy system contribution during subsequent exercise remains underexplored, although authors have suggested enhanced glycolytic flux via elevated post-exercise blood lactate (BLa -) concentration after a 75-90 min recovery (Gough et al, 2017b;Gough et al, 2019b).…”

Suplementação de bicarbonato de sódio e desempenho em exercício intermitentede alta intensidade: consistência dos efeitos e estratégias de otimização

“…Na suplementação aguda, a dose de 0.2 g•kg -1 MC já apresenta resultados positivos sobre o desempenho; no entanto, a melhor resposta é obtida com a dose de 0.3 g•kg -1 , que deve ser ingerida em única dose 60-120 minutos antes do início da prova (McNaughton 1992b;Peart et al 2012;Gurton et al 2020). A suplementação crônica é realizada com mais de um dia de duração, os protocolos variam de 2 a 10 dias, e a dose total é fracionada durante os dias de suplementação, podendo ainda ser fracionado em doses ainda menores durante cada dia de suplementação.…”