TY - JOUR
T1 - The influence of alkalosis on repeated high-intensity exercise performance and acid-base balance recovery in acute moderate hypoxic conditions
AU - Gough, Lewis Anthony
AU - Brown, Danny
AU - Deb, Sanjoy K.
AU - Sparks, S. Andy
AU - McNaughton, Lars R.
N1 - Publisher Copyright:
© 2018, The Author(s).
PY - 2018/12/31
Y1 - 2018/12/31
N2 - Purpose: Exacerbated hydrogen cation (H
+) production is suggested to be a key determinant of fatigue in acute hypoxic conditions. This study, therefore, investigated the effects of NaHCO
3 ingestion on repeated 4 km TT cycling performance and post-exercise acid–base balance recovery in acute moderate hypoxic conditions. Methods: Ten male trained cyclists completed four repeats of 2 × 4 km cycling time trials (TT
1 and TT
2) with 40 min passive recovery, each on different days. Each TT series was preceded by supplementation of one of the 0.2 g kg
−1 BM NaHCO
3 (SBC2), 0.3 g kg
−1 BM NaHCO
3 (SBC3), or a taste-matched placebo (0.07 g kg
−1 BM sodium chloride; PLA), administered in a randomized order. Supplements were administered at a pre-determined individual time to peak capillary blood bicarbonate concentration ([HCO
3
−]). Each TT series was also completed in a normobaric hypoxic chamber set at 14.5% FiO
2 (~ 3000 m). Results: Performance was improved following SBC3 in both TT
1 (400.2 ± 24.1 vs. 405.9 ± 26.0 s; p = 0.03) and TT
2 (407.2 ± 29.2 vs. 413.2 ± 30.8 s; p = 0.01) compared to PLA, displaying a very likely benefit in each bout. Compared to SBC2, a likely and possible benefit was also observed following SBC3 in TT
1 (402.3 ± 26.5 s; p = 0.15) and TT
2 (410.3 ± 30.8 s; p = 0.44), respectively. One participant displayed an ergolytic effect following SBC3, likely because of severe gastrointestinal discomfort, as SBC2 still provided ergogenic effects. Conclusion: NaHCO
3 ingestion improves repeated exercise performance in acute hypoxic conditions, although the optimal dose is likely to be 0.3 g kg
−1 BM.
AB - Purpose: Exacerbated hydrogen cation (H
+) production is suggested to be a key determinant of fatigue in acute hypoxic conditions. This study, therefore, investigated the effects of NaHCO
3 ingestion on repeated 4 km TT cycling performance and post-exercise acid–base balance recovery in acute moderate hypoxic conditions. Methods: Ten male trained cyclists completed four repeats of 2 × 4 km cycling time trials (TT
1 and TT
2) with 40 min passive recovery, each on different days. Each TT series was preceded by supplementation of one of the 0.2 g kg
−1 BM NaHCO
3 (SBC2), 0.3 g kg
−1 BM NaHCO
3 (SBC3), or a taste-matched placebo (0.07 g kg
−1 BM sodium chloride; PLA), administered in a randomized order. Supplements were administered at a pre-determined individual time to peak capillary blood bicarbonate concentration ([HCO
3
−]). Each TT series was also completed in a normobaric hypoxic chamber set at 14.5% FiO
2 (~ 3000 m). Results: Performance was improved following SBC3 in both TT
1 (400.2 ± 24.1 vs. 405.9 ± 26.0 s; p = 0.03) and TT
2 (407.2 ± 29.2 vs. 413.2 ± 30.8 s; p = 0.01) compared to PLA, displaying a very likely benefit in each bout. Compared to SBC2, a likely and possible benefit was also observed following SBC3 in TT
1 (402.3 ± 26.5 s; p = 0.15) and TT
2 (410.3 ± 30.8 s; p = 0.44), respectively. One participant displayed an ergolytic effect following SBC3, likely because of severe gastrointestinal discomfort, as SBC2 still provided ergogenic effects. Conclusion: NaHCO
3 ingestion improves repeated exercise performance in acute hypoxic conditions, although the optimal dose is likely to be 0.3 g kg
−1 BM.
KW - Buffers
KW - Alkalosis
KW - Individual pursuit
KW - Personalised nutrition
KW - Track cycling
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U2 - 10.1007/s00421-018-3975-z
DO - 10.1007/s00421-018-3975-z
M3 - Article (journal)
C2 - 30196448
SN - 1439-6319
VL - 118
SP - 2489
EP - 2498
JO - European Journal of Applied Physiology
JF - European Journal of Applied Physiology
IS - 12
ER -