I am a scientist by training, not a shill.
So I am not going to try and convince you to buy some mysterious powder from the Himalayas that will make you jacked.
I am, however, going to cut to the chase and tell you about why a few supplements might be worth taking to maximize your training.
The main reason for each of these is that they increase your ability to do work, which we know is the main dictator of how jacked you get during your bulk cycle.
The three on the list today are caffeine, beta-alanine, and citrulline.
Caffeine is touted as one of the most efficacious pre-workout supplements for increasing energy, focus, and training capacity. It is also thought to elicit the following: increased anaerobic running capacity, power output, adrenaline, aerobic exercise, blood glucose and fat oxidation, as well as decreased insulin sensitivity.
Caffeine primarily works by antagonizing (essentially blocking) adenosine receptors. Adenosine normally binds to these receptors, causing drowsiness. By antagonizing these receptors, caffeine can increase alertness and combat drowsiness.
Caffeine is also distributed throughout the body and interacts with receptors on the surfaces of other cells to elicit different physiological processes including the release of adrenaline and cortisol.
Several studies have shown that caffeine pre-workout can increase power output1, 2, 3. However, it appears to not be related to improvements in 1 repetition maximums but in “sustain power,” e.g. 3-5 RM and Wingate.
It may be due to a reduction in pain perception, and mobilization of intramuscular calcium (the stuff that lets your muscles actually contract).
There have been documented increases in aerobic capacity from caffeine supplementation4, 5, 6. This is potentially mediated by increased free fatty acid (FFA) release. However, contradictory evidence shows that adrenaline increased FFA release, thus decreasing FFA oxidation.
Dosing of caffeine is highly variable. Your genetics and habitual use of caffeine play a large role in how much is needed to elicit an effect. The more you consume on a daily basis, the more you will need to consume in order to see any training benefit.
Additionally, there appears to be a “saturation” limit where you only receive an anti-fatigue benefit and no additional effects from higher levels of caffeine intake.
Beta-alanine is the beta form of the amino acid alanine (meaning the amino group is in the beta position). It is the rate limiting (read bottleneck) precursor to a chemical called carnosine which acts as a buffer to prevent reductions in pH.
Beta-Alanine is purported to increase your training capacity by improving the body’s ability to buffer exercise-induced decreases in pH. In essence, Beta-alanine isn’t doing the work; it is providing your body with the ability to make more carnosine.
Beta-Alanine is a well-researched supplement with some actual evidence to support its use. However, there appears to be no real timing component and it does not necessarily have to be taken as a pre-workout.
Briefly, Beta-Alanine helps you avoid “hitting the wall” a little bit longer, essentially increasing your workload by 1-2 additional reps in the 8-15 rep range7, 8, 9. The consistent finding throughout the research is that it can increase your muscle endurance by about 2.5%.
It has also been shown to improve interval-type training, where individuals have improved performance in repeated bouts of sprint intervals.
In addition to Beta-Alanine increasing muscle endurance, there have been some small improvements in fat reduction reported in the literature10.
One important facet of this finding is that the research is unable to determine if it was directly due to supplementation, or if the increased fat loss was a result of the increased work during training. My guess, it works something like this.
Although it is marketed as a pre-workout supplement, there is little evidence to support a specific time-domain. You can take it at any time and you will receive the benefit as the goal is to increase your intramuscular carnosine levels. That being said, it can easily just be included in your pre-workout supplement and it works just fine.
The typical dose for beta-alanine is 2-5g/day. There have been reports of users getting a tingling feeling when consuming large doses of beta-alanine. This is scientifically known as paresthesia, I prefer to call it “itchy face”.
Splitting your daily dose into two smaller doses can alleviate this, if you decide that the itchy face feeling doesn’t get you jacked up to train. This has been shown to be as effective as a larger, once-daily dose.
Like creatine monohydrate, beta alanine has well documented benefits for increasing training capacity in certain training modalities. If you are looking for an extra few percent in your training, beta-alanine might be a useful tool.
L-citrulline has been shown to have a myriad of benefits in humans, including increased training volume, decreased muscle soreness, decreased fatigue, and increased blood flow.
In a fairly large (large as far as supplement research goes) double-blind placebo-controlled study, 41 participants supplemented with 8g of citrulline or placebo and performed 8 sets of bench press to fatigue. The citrulline group noticed a drastic improvement (52.92%) of reps they were able to achieve than the placebo11.
In this same study, the group receiving citrulline noted a 40% decrease in soreness at 24 and 48 hours compared to the placebo group. A separate study showed that supplementing with citrulline decreased fatigue during a rest-recovery style training protocol12.
Another well-known aspect of citrulline is the breakdown of citrulline into L-arginine. L-arginine then can be converted into nitric oxide and increase blood flow. In a small study of only 8 men, supplementing with 2 and 15g of citrulline increased arginine levels in the blood, and in a dose dependent manner13.
In a double-blind placebo-controlled trial of healthy men, citrulline supplementation did in fact increase serum nitric oxide and decrease a measure of arterial stiffness, indicating possible vasorelaxation14.
Given the large effect of citrulline on cardiovascular parameters and recent evidence from individuals with heart failure, L-citrulline may be an ideal supplement for individuals with cardiovascular problems15.
Besides changes in fatigue, soreness, and cardiovascular parameters there may be some positive effect of citrulline supplementation on growth hormone.
In one double-blind placebo-controlled study conducted in 17 young men, 6 grams of citrulline prior to exercise increased exercise induced growth hormone response almost 70%16. Currently, this aspect of citrulline needs to be validated with follow-up studies
Citrulline-malate displays a wide range of potential benefits from decreasing fatigue and increasing training volume to improving exercise capacity in individuals with heart failure.
While there are some reported gastrointenstinal side effects (similar to creatine), citrulline appears to be a well-tolerated supplement that has potential to be on par with creatine and beta-alanine in terms of efficacy. Doses of approximately 6g prior to exercise are the most common dosages observed in the literature.
As mentioned above, caffeine is one of the most effective pre-workout supplements on the market. However, overtime it can become ineffective for people due to the habituation effect. Think about the first time you took a caffeine loaded pre-workout versus yesterday. Is the kick still the same? Most likely the answer is no.
A new compound, theacrine (which goes by the brand name TeaCrine®), has recently surfaced in the sports performance world that may work similar to caffeine yet not have the downside of habituation.
As with any new compound, safety is the first bar that must be passed before we even begin to look at any potential benefits for training (yeah, I know, us conservative scientists want to know if it is going to kill us before we mainline it).
In a fairly robust safety study, 60 healthy men in their late teens and early twenties were randomized into three groups and given either a placebo, 200mg of theacrine or 300 mg of theacrine for 8 weeks17. In the study, there was no change in resting blood pressure, heart rate or breathing.
Furthermore, with regard to overall health and metabolic parameters there were no safety concerns with heart function of blood lipids or glucose. Overall the trial showed superb safety measures.
In a pilot investigation of theacrine involving dose response studies, 200 mg of theacrine reduced subjective levels of fatigue in two groups of people, suggesting it may have a similar effect on subjective energy levels as caffeine. These findings have been supported in separate study, leading to a greater likelihood the effect is real18.
Additionally, in a recent abstract presented at the International Society for Sports Nutrition, supplementing with 275mg of theacrine showed a benefit on time to exhaustion. Interestingly, it also appear to work synergistically with caffeine.
The combination of theacrine and caffeine is also currently being investigated as there is some evidence to suggest that caffeine may actually help augment the efficacy of theacrine supplementation
Based on the most current evidence we can draw a few conclusions about theacrine (TeaCrine®). First, it appears to be non-habituating which makes it an attractive compound to replace or augment caffeine supplementation. Second, it appears to be safe for human consumption with no currently reported negative health outcomes.
Third, it likely has an impact on perceived fatigue and may improve endurance capacity. Fourth, supplementing alongside caffeine may enhance theacrine’s efficacy. Fifth, this is an interest compound worth much more scientific investigation.
The Wrap Up
When it is time to bulk there is no reason to left stones unturned. Supplementing can be a key piece of your nutrition regime to help you get the last 2-5% of your gains.
Caffeine, Beta-Alanine, and Citrulline are 3 of the most proven, effective supplements you can use for increasing the volume and intensity of your training. Finally, Theacrine is a supplement to keep your eye on as more and more studies and research is conducted using the ingredient.
- Effects of caffeine on prolonged intermittent-sprint ability in team-sport athletes.
- Effect of two doses of caffeine on muscular function during isokinetic exercise.
- Dose response effects of a caffeine-containing energy drink on muscle performance: a repeated measures design.
- The influence of a CYP1A2 polymorphism on the ergogenic effects of caffeine.
- Effect of ambient temperature on caffeine ergogenicity during endurance exercise.
- The effects of different doses of caffeine on endurance cycling time trial performance.
- Important role of muscle carnosine in rowing performance.
- Effects of β-alanine supplementation on performance and body composition in collegiate wrestlers and football players.
- Short-duration beta-alanine supplementation increases training volume and reduces subjective feelings of fatigue in college football players.
- Effects of β-alanine supplementation on performance and body composition in collegiate wrestlers and football players.
- Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness.
- Citrulline/malate promotes aerobic energy production in human exercising muscle.
- Dose-ranging effects of citrulline administration on plasma amino acids and hormonal patterns in healthy subjects: the Citrudose pharmacokinetic study.
- Short-term effects of L-citrulline supplementation on arterial stiffness in middle-aged men.
- Effect of L-arginine or L-citrulline oral supplementation on blood pressure and right ventricular function in heart failure patients with preserved ejection fraction.
- L-citrulline-malate influence over branched chain amino acid utilization during exercise.
- Safety of TeaCrine®, a non-habituating, naturally-occuring purine alkaloid over weight weeks of continuous use.
- The effects of Teacrine™, a nature-identical purine alkaloid on subjective measures of cognitive function, psychometric and hemodynamic indices in healthy humans: a randomized, double-blinded crossover pilot trial.