The Impact of Individualizing Sodium Bicarbonate Supplementation Strategies on World-Class Rowing Performance

Abstract

Contemporary meta-analyses have generally demonstrated a positive effect of sodium bicarbonate (NaHCO 3) supplementation on exercise performance. However, despite these claims, there is limited data on contrasting individualized and standardized timing of NaHCO 3 ingestion prior to exercise to further enhance performance outcomes. Purpose: To determine whether NaHCO 3 ingestion timing impacts 2,000-m rowing time-trial (TT) performance in elite-level rowers (Senior National team including Olympic/World Championships level) adhering to their own individualized pre-race strategies (e.g. nutrition, warm-up, etc.). Methods: Twenty three (n = 23) rowers across two research centers (using the exact same methods/protocols) completed three trials: NaHCO 3 loading profile at rest to determine the individual's time-to-peak bicarbonate concentration [HCO − 3 ], followed by two randomized 0.3 g•kgBM −1 NaHCO 3 supplementation experimental trials conducted at different time points [consensus timing (CON): TT performed 60 min post-NaHCO 3 ingestion; and individualized peak (IP): TT performed at the rower's individual peak [HCO − 3 ] determined from the profiling trial post-NaHCO 3 ingestion]. Results: There was a significant mean difference of +2.9 [± 0.4 mmol•L −1 HCO − 3 for IP vs. CON (95% CI 2.0 to 3.8 mmol•L −1); p = 0.02; d = 1.08] at pre warm-up, but not immediately prior to the TT (post warm-up). Performance times were significantly different between IP (367.0 ± 10.5 s) vs. CON (369.0 ± 10.3 s); p = 0.007; d = 0.15). Conclusions: The present study demonstrated a small but significant performance effect of an individualized NaHCO 3 ingestion strategy. Similarities after warm-up between pre-TT sHCO − 3 values (CON ∼ + 5.5 mmol•L −1 ; IP ∼ + 6 mmol•L −1), however, would suggest this effect was not a result of any meaningful differences in blood alkalinity.

Does varying the ingestion period of sodium citrate influence blood alkalosis and gastrointestinal symptoms?

“…Further examination of post-ingestion blood alkalosis for more than 240 minutes may allow more precise recommendations regarding the timing of sodium citrate supplementation in relation to the commencement of exercise. It has been proposed that a 6 mmol.L -1 increase in blood [HCO 3 - ] following buffering agent ingestion may increase the likelihood of observing an ergogenic benefit [ 11 , 28 , 29 ]. However, it is unknown for how long elevated blood [HCO 3 - ] remains above the 6 mmol.L -1 threshold following sodium citrate ingestion, adding to the requirement for an extended post-ingestion observation period.…”

The time to peak blood bicarbonate (HCO3−), pH, and strong ion difference (SID) following sodium bicarbonate (NaHCO3) ingestion in highly trained adolescent swimmers

“…The close relationship between these two measurements is synonymous with previous research exploring the dose-response relationship of NaHCO 3 consumed in gelatine capsules [3,22,38]. The remainder of this discussion will therefore focus on HCO 3 − as this measurement typically displays less variance and a greater degree of reliability when compared with pH [2,21]. The time taken for trained adolescents to reach peak HCO 3 − concentrations ranged considerably within the present study (75 – 180 min), which is in accordance with similar research (40 – 240 min) when recreational adults ingested NaHCO 3 capsules in fed or fasted states [3,21,22].…”

“…The remainder of this discussion will therefore focus on HCO 3 − as this measurement typically displays less variance and a greater degree of reliability when compared with pH [2,21]. The time taken for trained adolescents to reach peak HCO 3 − concentrations ranged considerably within the present study (75 – 180 min), which is in accordance with similar research (40 – 240 min) when recreational adults ingested NaHCO 3 capsules in fed or fasted states [3,21,22]. The reason for the inter-individual variation remains elusive, though it is postulated that genetic differences in the rate of gastric emptying, intestinal motility, and gastrointestinal blood flow may contribute by influencing absorption characteristics [43,44].…”

“…This limited the current study from including a placebo experiment or repeatability measures which could have substantially altered the interpretation of results. Previous work analysing blood analyte time course changes using capillary bloods detected no changes from baseline for either HCO3 − , pH, or Na + when consuming a placebo treatment [2], whereas the time in which HCO3 − peaks in the bloodstream was considered to have a good repeatability (technical error = 14 min, ICC = 0.77) in highly trained athletes consuming 0.3 g·kg BM -1 NaHCO 3 in capsules [21]. However, it should be noted that both of these studies analysed blood variables under fasted conditions.…”

“…There is an apparent increase in the ergogenic potential of NaHCO 3 when blood HCO 3 − increases above baseline concentrations by 5 mmol·L -1 , whereas increases above 6 mmol·L -1 are associated with almost certain performance enhancement [19,20]. However, the time taken to reach these thresholds varies considerably when NaHCO 3 is consumed in either capsule (range: 40 – 240 min [3,21,22]), or solution form (range: 40 – 125 min [2,23–25]), therefore highlighting a potential flaw in the current dosing guidelines (i.e., 60 – 150 min pre-exercise for all athletes [1]). Contemporary research is addressing this issue by timing exercise to coincide with an individual peak in HCO 3 − concentration [21,23–25], though at present, only Boegman et al [21] has directly compared exercise performance between NaHCO3 ingested at an individual peak in HCO3 − (40 – 160 min pre-exercise) versus a traditionally recommended dosing protocol (60 min pre-exercise for all athletes).…”