Repeated bouts of high-intensity exercise lead to a pronounced accumulation of hydrogen cations (H+), a by-product of anaerobic metabolism that has been shown to play causative roles in peripheral fatigue.
β-alanine (BA) supplementation is effective to increase intracellular carnosine content, a dipeptide whose pKa of 6.83 falls within the mid-point of the pH transit range in skeletal muscle (pH ~ 7.0 at rest and ~ 6.5 at fatigue).
In this context, strategies have been used to attenuate acidosis and improve performance, with β-alanine (BA) and sodium bicarbonate (SB) supplementation being two of the most effective strategies capable of increasing H+ buffering capacity and exercise performance.
Subjects of Beta-Alanine and Sodium Bicarbonate do Not Improve Cycling Performance
To be included in the study, participants were required to meet the following criteria: non-vegetarian men between 18 and 45 years of age, actively training cycling at least three times per week, and a minimum of 6 h week−1, with at least 3 years of experience in cycling training. Exclusion criteria were: diagnosed with chronic diseases, use of BA or creatine 6 months prior to the study, smoking, and continued use of medications. Volunteers were fully informed of any risks and discomforts associated with the study before giving their signed consent for participation. The study was approved by the institution’s ethics committee.
The subjects in da Silva 2018 were 72 trained cyclists (5 ± 4 years of experience in cycling, 9 ± 3 h of training/week, consisting of 235 ± 92 km/week) with a VO2max of 59-60 ml/kg/min. This VO2max suggests they were highly trained.
Beta-alanine was preloaded for a month at a comparatively high dose (28 days at 6.4g/d; two capsules were ingested four times daily vs. maltodextrin (placebo).
The 0.3g/kg body weight of sodium bicarbonate (or calcium carbonate placebo) was supplemented within max. 5 minutes 60 minutes before the performance test in 1-g gelatin capsules under supervision to ensure full compliance. Gastrointestinal discomfort was reported prior to and 60 min using a 10-point scale - serial loading protocol as I've described it in previous articles about the bicarb was not used.
The food intake during the supplementation period was 'monitored' via 3-day food diaries the subjects had to fill on 2 non-consecutive weekdays and 1 weekend day. The analyses of these food logs showed that the subjects consumed ~2200kcal/d with approximately 52%, 18.5%, and 26.5% of the energy coming from carbs, protein, and fats, respectively - without inter-group differences.
The actual testing sessions that were conducted after pre-test and familiarization sessions consisted of a high-intensity intermittent cycling protocol (4x 60s at 110% of the subjects' individual maximal power-output with 60s rests between bouts) that was followed by a 30-kJ time-trial performance test. Both tests performed twice - once before and once after the 28 days of beta-alanine or placebo supplementation.
As it is necessary for any double-blind, parallel-group, placebo-controlled trial, the participants were randomly allocated to the BA (β-alanine + placebo; n = 20, 3 drop-outs), SB (placebo + sodium bicarbonate; n = 20, 3 drop-outs), BASB (β-alanine + sodium bicarbonate; n = 20, 1 drop-out), or PLA (placebo + placebo; n = 20, 2 drop-outs) groups and asked to identify their group allocation (i.e., BA or maltodextrin and SB or calcium carbonate) to verify the blinding process.
Results of Beta-Alanine and Sodium Bicarbonate do Not Improve Cycling Performance
da Silva et al. did not find a significant effect of any of the three supplementation protocols on the subjects exercise performance. Both, Figures below do not suggest significant performance improvements - with the largest effect size being and a borderline significant effect being observed in the BA + SB group.
Practical Implication of Beta-Alanine and Sodium Bicarbonate do Not Improve Cycling Performance
- da Silva RP, de Oliveira LF, Saunders B, de Andrade Kratz C, de Salles Painelli V, da Eira Silva V, Marins JCB, Franchini E, Gualano B, Artioli GG. Effects of β-alanine and sodium bicarbonate supplementation on the estimated energy system contribution during high-intensity intermittent exercise. Amino Acids. 2018 Sep 4. doi: 10.1007/s00726-018-2643-2. [Epub ahead of print]
Dr. John Mullen
DOCTOR OF PHYSICAL THERAPY
PERSONAL TRAINING WITH NATIONAL STRENGTH AND CONDITIONING ASSOCIATION
Dr. John Mullen, DPT, CSCS is a World renowned expert and speaker in sports training and rehabilitation. He received his Doctorate in Physical Therapy at USC, as well as the Josette Antonelli Division Service Scholarship, Order of the Golden Cane, and the Order of Areté. At USC, he also performed research on strength training and rehabilitation. Dr. John has worked with multiple professional and Olympic athletes, helping them earn Olympic medals.
His dedication to research and individualization spurred him to open COR in 2011. Since 2011, Dr. John has been featured in Gizmodo, Motherboard, Stack Magazine, and much more.
He has worked with the numerous colleges and teams regarding rehab and performance. Before his Doctoral program, Dr. John swam on an athletic scholarship at Purdue University.
At Purdue, Dr. John was an Academic Honorable Mention All-American and was awarded the Red Mackey Award and R. O. Papenguh Award. He also won the Purdue Undergraduate business plan and elevator pitch competition, as well as 1st prize with the Indiana Soy Bean Alliance.
Dr. John was born in Centerville, Ohio and was a 24-time high school All-American Swimmer. Dr. John is still a swimmer and holds a Masters Swimming World and Pacific Swimming Record.