Sodium bicarbonate supplementation improves muscle buffering capacity and the ability to tolerate higher lacate concentrations during high intensity efforts lasting from approximately 30 seconds to 10 minutes. Thus, enhances performance! How does that relate to cycling performance?
Sodium bicarbonate has been know for quite some time as an ergogenic aid, that can improve athletic performance in efforts lasting between approximately 30 seconds and 10 minutes.
Performances at maximal intensity within this time range requires a fairly big anaerobic energy supply from the glycolytic energy system. The glycolytic energy system is responsible for breaking down carbohydrates to energy without the use of oxygen (non-oxidative energy).
Efforts lasting from approximately 30 seconds to 3 minutes will rely heavily on the glycolytic energy system. Whereas during efforts from approximately 3 to 10 minutes the glycolytic energy supply will gradually decrease, but still be important for the overall performance.
Byproducts from the glycolytic energy process are lactate and hydrogen ions that accumulates within the working muscles. Accumulation of hydrogen ions during high intensity efforts causes acidosis, which in turn deteoriates the muscles capacity to produce anaerobic energy. Thus, hydogen ions plays an important role in muscle fatigue.
Sodium bicarbonate has the capacity to buffer (remove) hydrogen ions from the working muscles, and thereby reducing the decline in anaerobic energy production. Hence, sodium bicarbonate plays an important role in anaerobic work capacity by maintaining the hydrogen ion balance within the muscle.
In the figure (adopted from Grgic et al.) below you can see how much energy that is supplied by oxidative (aerobic) and non-oxidative (ATP-PCr and glycolysis) pathways during near maximal efforts. Futher it is illustrated during which exercise durations acidosis is greatest (reb bar), thus the durations where sodium bicarbonate supplementation (purple bar) will have the greatest impact on performance.
So to sum up! Supplementation of sodium bicarbonate increases the concentration of sodium bicarbonate in the body, and this leads to improved removal of hydrogen ions from the working muscles during intense exercise, i.e. less acidosis within the working muscles.
Consequently this enhances performance in high intensity near maximal efforts lasting from approximately 30 seconds to 10 minutes.
Supplementation - how much and when?
To get the desired effect from sodium bicarbonate supplementation, it should be ingested within the last 1-3 hours before training or competition. The optimal dose is 0.3 g/kg bodyweight. Supplementation protocols with 0.2 g/kg is considered the lowest dose that would elicit performance benefits. Higher doses (above 0.4 g/kg) does not provide further improvements in performance.
Supplementing with sodium biocarbonate can have some negative side effects, with higher doses causing bloating, nausea, vomiting and stomach pain. The risk of getting side effects is considered low if you stay within the 0.2-0.3 g/kg suppelmentation range.
A carbohydrate rich meal ingested at the same time as the supplementation, can help minimize the risk of getting the side effects. Further, ingesting sodium bicarbonte in capsules istead of dissolving it in a liquid, migth minimize the risk of negative side effects.
Suplementation can be done in a sigle dose (e.g. 0.3 g/kg 3 hours before), or as a multiple dose protocol where the total amount is either administered in smaller doses within the last 3 hours before exercise, or both within the last 3 hours and during the training session or competition.
Sodium bicarbonate and cycling performance
So what about cycling performance - would sodium bicarbonate supplementation be beneficial for optimizing performance?
Cycling, mountainbike or gravel races normally lasts longer than 10 minutes and are caracterized by an intermittent style of riding with periods of moderate intensity interspersed with periods of high intensity during break aways, tough climbs or the final sprint.
So the race formats as a whole is 'just' not all-out from the gun for a relatively short time period, thus not within the 'competition characteristics' where sodium bicarbonate supplementation enhances performane.
Numerous scientific studies have invenstigated the effects of bicarbonate on performance, and many of them have looked into how performance on the bike is affected.
A study from 2021 (Dalle et al.) looked into how sodium bicarbonate can improve sprint performance during endurance cycling. The participants in the study, whom where to be considered 'highly trained competitive cyclist', completed a 3 hour intermittent exercise protocol consisting of 6x30 minute blocks with the intensity within each block varying between 5 min @ 60 % and 5 min @ 90 % of their individual lactate threshold. After the last 30 min block cyclists compeletd a 90 second all out effort.
The particpants completed the 3 hour protocol on two separate occasions - one where they recieved sodium bicarbonate supplementation and one where they were given a placebo supplementation. Sodium bicarbonate was given to them prior to and during the cycling protocol, with the overall dose being 0.3 g/kg (one half provided before and the other half during). Results showed that ingesting sodium bicarbonate improved the 90 second final all-out performance by 3 %.
Another study from 2020 (Gurton et al.) looked into the difference between a 0.2 g/kg, 0.3 g/kg or placebo supplementation protocol on cycling performance. The test proptocol was rather short but intense, and consisted of 3x1 minute cycling @ 90, 95 and 100 % maximal aerobic power resepctively, with 5 minute recoveries in between. After the 3x1 minute efforts a time trail to exhaustion was completed. Results showed that both the 0.2 g/kg and 0.3 g/kg resulted in time trail improventes (longer time to exhaustion) compared to placebo, but the 0.3 g/kg protocol being superior to the 0.2 g/kg protocol.
Conclusion and recommendations
Overall the litterature clearly indicates that supplementation of sodium bicarbonate can improve high intensity cycling performance - even during longer races.
This relates to road cycling, mountainbike and gravel cycling performance, as all three disciplines involves high intensity efforts relying on the anaerobic energy system.
Doses within 0.2 and 0.3 grams per kilo is recommended, with the latter being favorable for performance.
Supplementation can be taken either as a single dose or a stacked dose (total amount administered over several small amounts) within the last 1-3 hours prior to training or competition.
Supplementation can be continued during exercise to sustain the performance effects of sodium bicabonate - this might be very important if it's a long duration event, where the anaerobic capacity is crucial for the finale decisive moments.
A carbohydrate rich meal ingested at the same time as the supplementation, can help minimize the risk of getting the negative side effects (bloating, nausea, vomiting and stomach pain).
Ingesting sodium bicarbonte in capsules istead of dissolving it in a liquid, migth minimize the risk of negative side effects.
If you want to try out sodium bicarbonate supplementation make sure to test it in training before using it for competition, as it is important to see how your body responds to the intake.
References:
Sebastiaan Dalle, Katrien Koppo and Peter Hespel (2021). Sodium bicarbonate improves sprint performance in endurance cycling. Journal of Science and Medicine in Sport 24, 301–306.
William H. Gurton, Lewis A. Gough, S. Andy Sparks, Mark A. Faghy and Katharine E. Reed (2020). Sodium Bicarbonate Ingestion Improves Time-to-Exhaustion Cycling Performance and Alters Estimated Energy System Contribution: A Dose-Response Investigation. Frontiers in Nutrition 7:154.
William H. Gurton, Guilherme G. Matta, Lewis Anthony Gough, Mayur Krachna Ranchordas, David G. King and Philip Hurst (2023). Sodium Bicarbonate and Time-to-Exhaustion Cycling Performance: A Retrospective Analysis Exploring the Mediating Role of Expectation. Sports Medicine 9:65.
Jozo Grgic, Zeljko Pedisic, Bryan Saunders, Guilherme G. Artioli, Brad J. Schoenfeld, Michael J. McKenna, David J. Bishop, Richard B. Kreider, Jeffrey R. Stout, Douglas S. Kalman, Shawn M. Arent, Trisha A. VanDusseldorp, Hector L. Lopez, Tim N. Ziegenfuss, Louise M. Burke, Jose Antonio and Bill I. Campbell (2021). International Society of Sports Nutrition position stand: sodium bicarbonate and exercise performance. Journal of the International Society of Sports Nutrition 18:61