Supplements under the microscope (Part 2) – Beta-alanine, Sodium Bicarbonate and Creatine
Following on from last month’s edition examining the ergogenic benefits of caffeine and nitrate, in this edition, the efficacy and performance perspectives of popular supplements beta-alanine, sodium bicarbonate and creatine will be discussed. In keeping with Part 1 of this series, the three supplements highlighted here have previously been demonstrated to exhibit evidence-based performance benefits across a range of exercise durations and intensities. The question is – how reliable and practical are these supplement performance gains to triathletes in competition, and for training adaptations?
Beta-alanine: More suited for high-intensity exercise between 30seconds and 10minutes.
Beta-alanine is a non-essential amino acid produced by the body, which amongst other things plays a role in regulating acid-base changes in exercising muscle. When consumed as a supplement at 3.2-6.4g per day over 2-4 weeks, muscle carnosine content increases by up to 65%, and contributes to improvements in tolerance to short bouts of maximal exercise (30seconds-10minutes; Saunders et. al 2016). While small performance gains in controlled lab-based studies have been observed, the practical application to endurance sports performance in the field is currently equivocal. Like most sports performance supplements, the ergogenic benefits of beta-alanine appear to diminish in highly trained (i.e. subsequently superiorly adapted) elite athletes compared to lesser-trained athletes.
Considerations for triathletes:
Beta-alanine can be taken as a single daily bolus dose. However, many athletes usually split the pre-prescribed dose over the day, primarily to lessen the magnitude of the most common side effects, including skin rashes, itchiness and sensations of “pins and needles”. There is intra-individual variability in the synthesis rate of beta-alanine, therefore dosage requirements may need to vary (between 1.6-6.4g per day) for a minimum of 2-4 weeks, in order achieve a 50% increase in muscle carnosine content. Since the peer-reviewed scientific literature reports performance benefits for high-intensity exercise between 30seconds and 10minutes, on the surface, it doesn’t appear to be a logical consideration for triathlon performance. The only plausible rationale for triathletes to consider beta-alanine supplementation would be to include specifically targeted pre-competition phase training adaptations.
Side effect: For all its benefits, Sodium Bicarbonate may give you a stomach ache.
Bicarbonate is produced naturally by the body, playing an important role in a range of physiological processes such as aiding digestion and regulating acid-base balance. Athletes have popularised the use of sodium bicarbonate (NaHCO³) loading for a number of decades, primarily as an ergogenic aid for high-intensity exercise that is typically characterised by significant glycolytic metabolic demands (e.g. 1-10minutes duration). Well established responses to NaHCO³ loading during intense exercise includes an increase in extracellular bicarbonate concentration; attenuation of the rise in muscle and blood hydrogen concentration and maintaining the important function of key regulatory enzymes that are central to the muscles contractile capacity. Subsequently, blood lactate production and efflux are typically greater during exercise in a NaHCO³ loaded state compared to no intervention, which in part contributes to increased energy availability. During the past 10-15 years, a number of studies have also demonstrated a NaHCO³ induced improvement in strong ion regulation (such as potassium), which in turn mitigates the effect of exercise-induced fatigue on muscle cell membrane excitability and contractile properties. Numerous studies have investigated the effects of NaHCO³ on enduring athlete performance, with mixed and inconsistent results – mostly due to high variability between participants. A study by Egger and colleagues (2014) observed an improvement in cycling time trial performance with NaHCO³ (30 min at 95% of the individual anaerobic threshold (IAT) followed by 110% IAT until exhaustion), however, the inter-individual variability was high.
The NaHCO³ loading protocol that consistently produces the most significant performance outcomes (~2-8% enhancement) requires 0.3g.kg-1 NaHCO3 consumed in 5 equal doses of water (200ml each dose), over a 1hr period, commencing 1-3hours prior to the start of competition.
Considerations for triathletes:
The NaHCO³ induced performance gains during intense exercise <10minute duration may not add much metabolic value to endurance performance that typifies triathlon race distances. However, performance gains in some individuals during prolonged cycling tests demonstrate some promise for selective individuals, although the mechanisms behind inter-individual variability in longer NaHCO³ are currently inconclusive. Furthermore, numerous studies have demonstrated an increase in plasma volume following NaHCO³ loading, which subsequently may add circulatory and thermoregulatory value to the physiological requirements of triathletes during endurance events – particularly in warm/hot environments.
The most common side effect experienced during the later stages of NaHCO³ loading includes gastrointestinal upset. To counter this less than desirable side effect, athletes are advised to ensure that adequate fluid accompanies each dose, and/or to add a small, carbohydrate-rich meal (∼1.5 g.kg-1 BM carbohydrate), or administering smaller doses over hours or several days prior to competition.
Creatine is naturally produced by the body via a number of amino acids, which are then stored in skeletal muscle and liberated during muscle contractions to support energy demands during muscle contractions. A large number of scientific studies over many decades has demonstrated the efficacy of supplementing with creatine monohydrate to increase the intramuscular creatine pool by ~30%. Subsequently, an elevation in available creatine stores provokes a greater rate of phosphocreatine synthesis, and enhances muscle contractile force, particularly during repeated bouts of intense exercise. The most common ergogenic method of creatine loading requires 20g creatine per day for 5 days. Performance improvements of 1-5% and 5-15% are commonly observed during single (<30s) and repeated (<150s) high-intensity bouts of exercise, respectively. Furthermore, chronic improvements in lean muscle mass, strength and power have been found following creatine loading. Encouragingly, there is also recent evidence of endurance performance gains. A study by Tomcik and colleagues (2018) demonstrated that combining creatine (5 days at 20g.day-1 followed by 9 days at 3g.day-1) with carbohydrate (9 days at 6-12g.day-1) produced a significant increase in repeated sprint power output during the late stages of a 3hr simulated cycling
Considerations for triathletes:
Triathletes may consider creatine loading from both an endurance performance perspective during competition, and from a targeted strength training adaptive perspective. The most common side effects following creatine loading include weight gain from water retention, gastrointestinal upset, and muscle cramping. The protocol that characterises the greatest level of ergogenic efficacy includes a preliminary loading phase of 20g.day-1 over 5 days (divided into multiple 5g doses throughout a given day), followed by a maintenance phase of 3-5g.day-1 for 7-14 days. Furthermore, combining 50g of protein and carbohydrate with each loading and maintenance dose of creatine appears to facilitate a more effective uptake into muscle.
In keeping with concluding remarks in Part 1 last month, athletes who are considering the use of beta-alanine, sodium bicarbonate or creatine for indirect and direct performance benefits, should be appropriately informed and risk assessed by a practitioner with significant sports supplements experience. Once it is deemed safe to proceed with a targeted event or training period, athletes should validate for the appropriate dose that exhibits tolerability. Generally speaking, the magnitude of ergogenic benefits with all legal sports supplements are expected to be smaller in relation to higher standard athletes
Peeling, P., et al (Int J Sport Nutr Ex Metab, 2018). Evidence-Based Supplements for the Enhancement of Athletic Performance
Saunders, B., et al (Br J Sports Med, 2016). Beta-Alanine supplementation to improve exercise capacity and performance: A systematic review and meta-analysis.
Egger, F., et al (PLoS One, 2014). Effects of Sodium Bicarbonate on High-Intensity Endurance
Performance in Cyclists: A Double-Blind, Randomized Cross-Over Trial.
Tomcik, K.A., et al (Med Sci Sp Ex, 2018). Effects of creatine and carbohydrate loading on cycling time