Exercise protocols employing a time to exhaustion or total work performance measure resulted in a much higher ES than the overall ES (0.60 and 0.63, respectively). The time to exhaustion ES however was lowered when the weighted mean is observed (0.50). In contrast, those studies using performance time or power as a performance measure resulted in much lower ESs of 0.17 and 0.27, respectively, with performance time reducing to 0.09 after weighting. Despite this, there were no significant differences in ESs between performance measures (F = 2.03, p = 0.12). None of the differences between exercise duration were significant (p = 0.501).
There was a moderate but significant overall relationship between ES and the state of induced alkalosis (n = 27, r = 0.45, p = 0.02), and this relationship was stronger in trained than in untrained participants (n = 15, r = 0.56, p = 0.03 and n = 12, r = 0.50, p = 0.10, respectively). The overall relationship between ES and the state of induced acidosis was weak and insignificant (n = 24, r = 0.25, p = 0.237).
The overall ES was higher in studies employing time to exhaustion or total work completed as a performance measure rather than performance time or power. However, the time to exhaustion and total work groups had a high proportion of untrained subjects, whereas the performance time group had a high proportion of trained subjects (only 1 untrained ES in group), therefore influencing the overall ESs. It is interesting that trained subjects in the performance time group had one of the lowest ESs, because it could be argued that this combination would be most applicable to elite sporting performance. Despite the differences between performance measures, there were no statistically significant differences in overall ESs. The absence of statistical differences between performance measures could be because of the differences in the size of the data sets between groups, coupled with the large confidence intervals, which often resulted in negative values at the lower 95% limit.
The most common duration of exercise protocols used to investigate the use of NaHCO3 was up to approximately 120 seconds (Table 2). This is presumable because high-intensity efforts of this duration are predominantly associated with anaerobic glycolysis. However, the overall ES for this duration of exercise was no different to medium (2–10 minutes) and long (>10-minute) duration protocols. Within the short duration category, the ES is much higher in untrained than in trained subjects, again suggesting that untrained subjects are more reliant on the extra buffering potential afforded by NaHCO3. However, once more, the confidence intervals must be taken into consideration. The similar overall ESs across exercise durations may suggest that the extra buffering capacity is not the sole mechanism behind its potential effect on performance. There has been some work to suggest that NaHCO3 may improve perceptual responses to exercise, which could account for the similarly moderate ES for longer exercise protocols (67,81,82). However, as with most research regarding NaHCO3, there is also a wealth of evidence on the contrary (1,60,78,93,95).
Future research should focus where possible on trained subjects performing sport-specific tasks, such as those studies on boxing (73), water polo (83), rugby (11), judo (1), and BMX cycling (94,95). Such research would avoid inflating the efficacy of NaHCO3 with untrained subjects who are unlikely to use it and so allow coaches, nutritionists, and athletes to make more informed decisions about their respective sport.
The authors wish to thank all those authors who provided us with missing data not available in their published articles.
1. Artioli GG, Gualano B, Coelho DF, Benatti FB, Galley AW, Lancha AH. Does sodium-bicarbonate ingestion improve simulated judo performance? Int J Sport Nutr Exerc Metab 17:206–217, 2007.
2. Aschenbach W, Ocel J, Craft L, Ward C, Spangenburg E, Williams J. Effect of oral sodium loading on high-intensity arm ergometry in college wrestlers. Med Sci Sports Exerc 32:669–675, 2000.
3. Balberman SE, Roby FB. The effects of induced alkalosis
and acidosis on the work capacity of the quadriceps and hamstrings muscle groups. Int J Sports Med 4:143, 1983.
4. Bird SR, Wiles J, Robbins J. The effect of sodium bicarbonate ingestion on 1500-m racing time. J Sports Sci 13:399–403, 1995.
5. Bishop D, Claudius B. Effects of induced metabolic alkalosis
on prolonged intermittent-sprint performance. Med Sci Sports Exerc 37:759–767, 2005.
6. Bishop D, Edge J, Davis C, Goodman C. Induced metabolic alkalosis
affects muscle metabolism and repeated-sprint ability. Med Sci Sports Exerc 36:807–813, 2004.
7. Bouissou P, Defer G, Guezennec CY, Estrade PY, Serrurier B. Metabolic and blood catecholamine responses to exercise during alkalosis
. Med Sci Sports Exerc 20:228–232, 1988.
8. Brien D, McKenzie D. The effect of induced alkalosis
and acidosis on plasma lactate and work output in elite oarsmen. Eur J Appl Phsiol Occup Physiol 58:797–802, 1989.
9. Burke LM, Pyne DB. Bicarbonate loading to enhance training and competitive performance. Int J Sport Physiol Perform 2:93–97, 2007.
10. Calfee R, Fadale P. Popular ergogenic drugs and supplements in young athletes. Pediatrics 117:e577–e589, 2006.
11. Cameron SL, McLay-Cooke RT, Brown RC, Gray AR, Fairbairn KA. Increased blood pH but not performance with sodium bicarbonate supplementation in elite rugby union players. Int J Sport Nutr Exerc Metab 20:307–321, 2010.
12. Carr AJ, Gore CJ, Dawson B. Induced alkalosis
and caffeine supplementation: Effects on 2,000-m rowing performance. Int J Sport Nutr Exerc Metab 21:357–364, 2011.
13. Carr AJ, Slater GJ, Gore CG, Dawson B, Burke LM. Effect of sodium bicarbonate on [HCO3 −
], pH, and gastrointestinal symptoms. Int J Sport Nutr Exerc Metab 21:189–194, 2011.
14. Cho S, Chung D, Park S, Choi I. The effect of induced metabolic alkalosis
with sodium bicarbonate on racing time, maximal oxygen uptake and anaerobic lactate threshold in competitive cyclists. Korean J Sports Sci 2:71–84, 1990.
15. Coombes J, McNaughton LR. Effects of bicarbonate ingestion on leg strength and power during isokinetic knee flexion and extension. J Strength Cond Res 7:241–249, 1993.
16. Costill DL, Verstappen F, Kuipers H, Janssen E, Fink W. Acid-base balance during repeated bouts of exercise: Influence of HCO3
. Int J Sports Med 5:228–231, 1984.
17. Dennig H, Talbott JH, Edwards HT, Dill DB. Effect of acidosis and alkalosis
upon capacity for work. J Clin Invest 9:601–613, 1931.
18. Dill DB, Edwards HT, Talbott JH. Alkalosis
and the capacity for work. J Biol Chem 97:58–59, 1932.
19. Edge J, Bishop D, Goodman C. The effects of training intensity on muscle buffer capacity in females. Eur J Appl Physiol 96:97–105, 2006.
20. Gaitanos GC, Nevill ME, Brooks S, Williams C. Repeated bouts of sprint running after induced alkalosis
. J Sports Sci 9:355–370, 1991.
21. Gao J, Costill D, Horswill C, Park S. Sodium bicarbonate ingestion improves performance in interval swimming. Eur J Appl Physiol Occup Physiol 58:171–174, 1988.
22. Goldfinch J, McNaughton L, Davies P. Induced metabolic alkalosis
and its effects on 400-m racing time. Eur J Appl Physiol Occup 57:45–48, 1988.
23. Hooker S, Morgan C, Wells C. Effect of sodium bicarbonate ingestion on time to exhaustion and blood lactate of 10k runners. Med Sci Sports Exerc 19:S68, 1987.
24. Horswill CA, Costill DL, Fink WJ, Flynn MG, Kirwan JP, Mitchell JB, Houmard JA. Influence of sodium bicarbonate on sprint performance: Relationship to dosage. Med Sci Sports Exerc 20:566–569, 1988.
25. Housh T, deVries H, Johnson G, Evans S, McDowell S. The effect of ammonium chloride and sodium bicarbonate ingestion on the physical working capacity at the fatigue threshold. Eur J Appl Phsiol Occup Physiol 62:189–192, 1991.
26. Hunter AM, De Vito G, Bolger C, Mullany H, Galloway SDR. The effect of induced alkalosis
and submaximal cycling on neuromuscular response during sustained isometric contraction. J Sports Sci 27:1261–1269, 2009.
27. Inbar O, Rotstein A, Jacobs I, Kaiser P, Dlin R, Dotan R. The effects of alkaline treatment on short-term maximal exercise. J Sports Sci 1:95–104, 1983.
28. Iwaoka K, Okagawa S, Mutih Y, Miyashita M. Effects of bicarbonate ingestion on the respiratory compensation threshold and maximal exercise performance. Jpn J Physiol 39:255–265, 1989.
29. Jones NL, Sutton JR, Taylor R, Toews CJ. Effect of pH on cardiorespiratory and metabolic responses to exercise. J Appl Physiol 43:959–964, 1977.
30. Joyce S, Minahan C, Anderson M, Osborne M. Acute and chronic loading of sodium bicarbonate in highly trained swimmers. Eur J Appl Physiol 112:1–9, 2011.
31. Juel C. Regulation of pH in human skeletal muscle: Adaptations to physical activity. Acta Physiol 193:17–24, 2008.
32. Katz A, Costill DL, King DS, Hargreaves M, Fink WJ. Maximal exercise tolerance after induced alkalosis
. Int J Sports Med 5:107–110, 1984.
33. Kindermann W, Keul J, Huber G. Physical exercise after induced alkalosis
(bicarbonate or tris-buffer). Eur J Appl Phsiol Occup Physiol 37:197–204, 1977.
34. Kowalchuk JM, Heigenhauser GJ, Jones NL. Effect of pH on metabolic and cardiorespiratory responses during progressive exercise. J Appl Physiol 57:1558–1563, 1984.
35. Kozak-Collins K, Burke ER, Schoene RB. Sodium-bicarbonate ingestion does not improve performance in women cyclists. Med Sci Sports Exer 26:1510–1515, 1994.
36. Kupcis PD, Slater GJ, Pruscino CL, Kemp JG. Influence of sodium bicarbonate on performance and hydration in lightweight rowing. Int J Sport Physiol Perf 7:11–18, 2012.
37. Lavender G, Bird SR. Effect of sodium bicarbonate ingestion upon repeated sprints. Brit J Sports Med 23:41–45, 1989.
38. Linderman J, Kirk L, Musselman J, Dolinar B, Fahey TD. The effects of sodium bicarbonate and pyridoxine-alpha-ketoglutarate on short-term maximal exercise capacity. J Sports Sci 10:243–253, 1992.
39. Lindh AM, Peyrebrune MC, Ingham SA, Bailey DM, Folland JP. Sodium bicarbonate improves swimming performance. Int J Sports Med 29:519–523, 2008.
40. Margaria R, Aghemo P, Sassi G. Effect of alkalosis
on performance and lactate formation in supramaximal exercise. Eur J Appl Phsiol Occup Physiol 29:215–223, 1971.
41. Marx J, Gordon S, Vos N, Nindl B, Gómez A, Volek J, Pedro J, Ratamess N, Newton R, French D, Rubin M, Häkkinen K, Kraemer W. Effect of alkalosis
on plasma epinephrine responses to high intensity cycle exercise in humans. Eur J Appl Physiol 87:72–77, 2002.
42. Materko W, Santos EL, Novaes JS. Effect of bicarbonate supplementation on muscular strength. J Exerc Physiol Online 11:25–33, 2008.
43. Matson LG, Tran ZV. Effects of sodium bicarbonate ingestion on anaerobic performance: A meta-analytic review. Int J Sport Nutr 3:2–28, 1993.
44. Matsuura R, Arimitsu T, Kimura T, Yunoki T, Yano T. Effect of oral administration of sodium bicarbonate on surface EMG activity during repeated cycling sprints. Eur J Appl Physiol 101:409–417, 2007.
45. Maughan RJ. Contamination of dietary supplements and positive drug tests in sport. J Sports Sci 23:883–889, 2005.
46. McCartney N, Heigenhauser GJ, Jones NL. Effects of pH on maximal power output and fatigue during short-term dynamic exercise. J Appl Physiol 55:225–229, 1983.
47. McClung M, Collins D. “Because I know it will!”: Placebo effects of an ergogenic aid
on athletic performance. J Sport Exerc Psychol 29:382–394, 2007.
48. McKenzie DC. Changes in urinary pH following bicarbonate loading. Can J Sport Sci 13:254–256, 1988.
49. McNaughton L, Dalton B, Palmer G. Sodium bicarbonate can be used as an ergogenic aid
in high-intensity, competitive cycle ergometry of 1 h duration. Eur J Appl Physiol Occup Physiol 80:64–69, 1999.
50. McNaughton LR. Bicarbonate ingestion: Effects of dosage on 60 s cycle ergometry. J Sports Sci 10:415–423, 1992.
51. McNaughton LR. Sodium bicarbonate ingestion and its effects on anaerobic exercise of various durations. J Sports Sci 10:425–435, 1992.
52. McNaughton LR, Siegler JC, Midgley A. The ergogenic effect of sodium bicarbonate. Curr Sport Med Rep 7:230–236, 2008.
53. Mero AA, Keskinen KL, Malvela MT, Sallinen JM. Combined creatine and sodium bicarbonate supplementation enhances interval swimming. J Strength Cond Res 18:306–310, 2004.
54. Nieper A. Nutritional supplement practices in UK junior national track and field athletes. Br J Sports Med 39:645–649, 2005.
55. Parry-Billings M, MacLaren DP. The effect of sodium bicarbonate and sodium citrate ingestion on anaerobic power during intermittent exercise. Eur J Appl Physiol Occup Physiol 55:524–529, 1986.
56. Pierce EF, Eastman NW, Hammer WH, Lynn TD. Effect of induced alkalosis
on swimming time trials. J Sports Sci 10:255–259, 1992.
57. Portington KJ, Pascoe DD, Webster MJ, Anderson LH, Rutland RR, Gladden LB. Effect of induced alkalosis
on exhaustive leg press performance. Med Sci Sports Exerc 30:523–528, 1998.
58. Potteiger JA, Webster MJ, Nickel GL, Haub MD, Palmer RJ. The effects of buffer ingestion on metabolic factors related to distance running performance. Eur J Appl Phsiol Occup Physiol 72:365–371, 1996.
59. Poulus A, Docter H, Westra H. Acid-base balance and subjective feelings of fatigue during physical exercise. Eur J Appl Phsiol Occup Physiol 33:207–213, 1974.
60. Price M, Moss P, Rance S. Effects of sodium bicarbonate ingestion on prolonged intermittent exercise. Med Sci Sports Exerc 35:1303–1308, 2003.
61. Price MJ, Simons C. The effect of sodium bicarbonate ingestion on high-intensity intermittent running and subsequent performance. J Strength Cond Res 24:1834–1842, 2010.
62. Pruscino CL, Ross MLR, Gregory JR, Savage B, Flanagan TR. Effects of sodium bicarbonate, caffeine, and their combination on repeated 200-m freestyle performance. Int J Sport Nutr Exerc Metab 18:116–130, 2008.
63. Raymer GH, Marsh GD, Kowalchuk JM, Thompson RT. Metabolic effects of induced alkalosis
during progressive forearm exercise to fatigue. J Appl Physiol 96:2050–2056, 2004.
64. Renfree A. The time course for changes in plasma [H+] after sodium bicarbonate ingestion. Int J Sport Physiol Perform 2:323–326, 2007.
65. Requena B, Zabala M, Padial P, Feriche B. Sodium bicarbonate and sodium citrate: Ergogenic aids? J Strength Cond Res 19:213–224, 2005.
66. Robergs R, Hutchinson K, Hendee S, Madden S, Siegler J. Influence of pre-exercise acidosis and alkalosis
on the kinetics of acid-base recovery following intense exercise. Int J Sport Nutr Exerc Metab 15:59–74, 2005.
67. Roberston RJ, Falkel JE, Drash AL, Swank AM, Metz KF, Spungen SA, LeBoeuf JR. Effect of blood pH on peripheral and central signals of perceived exertion. Med Sci Sports Exerc 18:114–122, 1986.
68. Robertson RJ, Falkel JE, Drash AL, Swank AM, Metz KF, Spungen SA, Leboeuf JR. Effect of induced alkalosis
on physical work capacity during arm and leg exercise. Ergonomics 30:19–31, 1987.
69. Ronsen O, Sundgot-Borgen J, Maehlum S. Supplement use and nutritional habits in Norwegian elite athletes. Scand J Med Sci Sports 9:28–35, 1999.
70. Rupp JC, Bartels RL, Zuelzer W, Fox EL, Clark RN. Effect op sodium bicarbonate digestion on blood and muscle pH and exercise performance. Med Sci Sports Exerc 15:115, 1983.
71. Shelton J, Praveen Kumar GV. Sodium bicarbonate—A potent ergogenic aid
? Food Nutr Sci 1:1–4, 2010.
72. Siegler JC, Gleadall-Siddall DO. Sodium bicarbonate ingestion and repeated swim sprint performance. J Strength Cond Res 24:3105–3111, 2010.
73. Siegler JC, Hirscher K. Sodium bicarbonate ingestion and boxing performance. J Strength Cond Res 24:103–108, 2010.
74. Siegler JC, Keatley S, Midgley AW, Nevill AM, McNaughton LR. Pre-exercise alkalosis
and acid-base recovery. Int J Sports Med 29:545–551, 2008.
75. Siegler JC, McNaughton LR, Midgley AW, Keatley S, Hillman A. Metabolic alkalosis
, recovery and sprint performance. Int J Sports Med 31:797–802, 2010.
76. Siegler JC, Midgley AW, Polman RCJ, Lever R. Effects of various sodium bicarbonate loading protocols on the time-dependent extracellular buffering
profile. J Strength Cond Res 24:2551–2557, 2010.
77. Sostaric SM, Skinner SL, Brown MJ, Sangkabutra T, Medved I, Medley T, Selig SE, Fairweather I, Rutar D, McKenna MJ. Alkalosis
increases muscle K+ release, but lowers plasma [K+] and delays fatigue during dynamic forearm exercise. J Physiol 570:185–205, 2006.
78. Stephens TJ, McKenna MJ, Canny BJ, Snow RJ, McConell GK. Effect of sodium bicarbonate on muscle metabolism during intense endurance cycling. Med Sci Sports Exerc 34:614–621, 2002.
79. Sutton JR, Jones NL, Toews CJ. Growth hormone secretion in acid-base alterations at rest and during exercise. Clin Sci Mol Med 50:241–247, 1976.
80. Sutton JR, Jones NL, Toews CJ. Effect of pH on muscle glycolysis during exercise. Clin Sci (Lond) 61:331–338, 1981.
81. Swank A, Robertson RJ. Effect of induced alkalosis
on perception of exertion during intermittent exercise. J Appl Physiol 67:1862–1867, 1989.
82. Swank AM, Roberston RJ. Effect of induced alkalosis
on perception of exertion during exercise recovery. J Strength Cond Res 16:491–499, 2002.
83. Tan F, Polglaze T, Cox G, Dawson B, Mujika I, Clark S. Effects of induced alkalosis
on simulated match performance in elite female water polo players. Int J Sport Nutr Exerc Metab 20:198–205, 2010.
84. Tiryaki GR, Atterbom HA. The effects of sodium bicarbonate and sodium citrate on 600 m running time of trained females. J Sports Med Phys Fitness 35:194–198, 1995.
85. Van Montfoort MCE, Van Dieren L, Hopkins WG, Shearman JP. Effects of ingestion of bicarbonate, citrate, lactate, and chloride on sprint running. Med Sci Sports Exerc 36:1239–1243, 2004.
86. Vanhatalo A, McNaughton LR, Siegler J, Jones AM. Effect of induced alkalosis
on the power-duration relationship for “All-out” Exercise. Med Sci Sports Exerc 42:563–570, 2010.
87. Verbitsky O, Mizrahi J, Levin M, Isakov E. Effect of ingested sodium bicarbonate on muscle force, fatigue, and recovery. J Appl Physiol 83:333–337, 1997.
88. Wahl P, Zinner C, Achtzehn S, Bloch W, Mester J. Effect of high- and low-intensity exercise and metabolic acidosis on levels of GH, IGF-I, IGFBP-3 and cortisol. Growth Horm IGF Res 20:380–385, 2010.
89. Webster MJ, Webster MN, Crawford RE, Gladden LB. Effect of sodium bicarbonate ingestion on exhaustive resistance exercise performance. Med Sci Sports Exerc 25:960–965, 1993.
90. Weston AR, Myburgh KH, Lindsay FH, Dennis SC, Noakes TD, Hawley JA. Skeletal muscle buffering
capacity and endurance performance after high-intensity interval training by well-trained cyclists. Eur J Appl Phsiol Occup Physiol 75:7–13, 1996.
91. Wijnen S, Verstappen F, Kuippers H. The influence of intravenous sodium bicarbonate administration on interval exercise: Acid-base balance and endurance. Int J Sports Med 5:130–132, 1984.
92. Wilkes D, Gledhill N, Smyth R. Effect of acute induced metabolic alkalosis
on 800-m racing time. Med Sci Sports Exerc 15:277–280, 1983.
93. Wu C-L, Shih M-C, Yang C-C, Huang M-H, Chang C-K. Sodium bicarbonate supplementation prevents skilled tennis performance decline after a simulated match. J Int Soc Sports Nutr 7:33, 2010.
94. Zabala M, Peinado A, Calderón F, Sampedro J, Castillo M, Benito P. Bicarbonate ingestion has no ergogenic effect on consecutive all out sprint tests in bmx elite cyclists. Eur J Appl Physiol 111:1–8, 2011.
95. Zabala M, Requena B, Sanchez-Munoz C, Gonzalez-Badillo JJ, Garcia I, Oopik V, Paasuke M. Effects of sodium bicarbonate ingestion on performance and perceptual responses in a laboratory-simulated BMX cycling qualification series. J Strength Cond Res 22:1645–1653, 2008.
96. Zajac A, Cholewa J, Poprzecki S, Waskiewicz Z, Langfort J. Effects of sodium bicarbonate ingestion on swim performance in youth athletes. J Sports Sci Med 8:45–50, 2009.