Guide to Pre-Workout Supplements

Picture this for a moment:

It’s the end of a long and stressful day, and training time is near. You’re tired and unmotivated, but you know you need to get your workout done.

You reach for your pre-workout, mix a scoop or two with water and the magic happens - you become alert, energized, and motivated to crush the weights.

Now back to reality:

You mix a scoop of pre-workout with some water, gulp it down, and nothing happens. After a while, you feel a slight tingle of energy.

Sadly, the second scenario is much more common because the market is littered with ineffective pre-workouts designed to bring in a few quick bucks.

But what can we do about it? Is all hope lost for the customer?

What Makes a Pre-Workout Supplement Effective

Along with the excitement of searching for a new pre-workout supplement comes the dread of sifting through hundreds of options. All of them are well-packaged and highly marketed. Each one is ‘revolutionary,’ and with a ‘new and improved’ formula.

And if that’s not enough to get you on board, you can be sure that there is a fitness model out there who vouches for the product and attributes their great physique to it.

But fancy marketing aside, what makes a product great is not the label or a random endorsement, but what’s inside it.

So, you can go ahead and buy the product with the best marketing team behind it, or you can learn what makes a pre-workout effective, do your research, and get your money’s worth. The place to start is on the label, looking for the below ingredients in appropriate doses.


Citrulline is an amino acid that is converted to L-Arginine in the kidneys after supplementation. So far, the research is in agreement that citrulline’s help in nitric oxide production improves our aerobic performance, boosts our strength, and reduces muscle soreness (1, 2, 3, 4).

For performance-enhancing benefits, a dose of 6 to 8 grams taken before working out has been shown to be the most effective (5).

But you might be wondering, “Why not just supplement with L-Arginine then?”

We’ll cover that below.


Theanine is a non-essential amino acid that has been shown to induce relaxation without the associated feeling of sleepiness (6). Theanine has also been suggested to reduce the perception of stress (7).

What’s more interesting is that theanine appears to work synergistically with the stimulant caffeine (8, 9, 10).

There is no doubt that increased alertness, focus, and mood are all essential factors of better training performance. Plus, research also suggests that theanine increases nitric oxide production, thus improving blood flow to the muscles (11).

For the best effect, take a dose of 100-250 mg alongside a similar amount of caffeine (12).


Caffeine is one of the most widely used stimulants on the planet. Millions of people rely on their daily dose of it to feel awake and alert.

The stimulant has been shown to elevate the resting metabolic rate and help subjects burn a few extra calories without moving more (13).

Caffeine has also been shown to increase strength, improve anaerobic capabilities, and boost endurance (14, 15).

Taking advantage of caffeine to increase performance is a good idea. The issue is, your body builds up a tolerance to caffeine, and you’d have to progressively increase the dose for it to be effective. The other option is to cycle caffeine.

Also, keep in mind that caffeine can interfere with your sleep (16). If you usually train in the evening, make sure to take a smaller dose.

Which Ingredients Work, But Might Not Be Needed in a Pre-Workout Supplement

Unlike the ingredients we just covered, the below ones can deliver performance-enhancing benefits, but you don’t necessarily need to take them as part of a pre-workout. Let’s take a look.


There’s no doubt that beta-alanine improves performance, but whether you should take it mostly depends on your training style.

A meta-analysis from 2012 examined fifteen studies (17). There were a total of 360 participants. Half were given beta-alanine, and half were given a placebo. Three exercise durations were measured: <1 minute, 1-3 minutes, and 3+ minutes. Here’s what the researchers found:

1) For the 14 measures lasting <60 s there was no significant difference between the effect sizes in the BA and Pla groups;

2) For the 9 measures lasting 60–240 s there was a significant difference between the effect size of the BA and Pla groups

3) once exercise duration increased over 240 s the beneficial effects of β-alanine supplementation from the 34 measures become less pronounced, although still significant;

If you regularly do bouts of training for 1-3 minutes without rest, beta-alanine can work great for you. Think CrossFit, interval running, and circuit-style training. Otherwise, don’t expect to gain much from supplementing with it.

As for dosing, research suggests that two to five grams per day are enough (18). The timing doesn’t matter.


Many pre-workouts out there contain creatine, and that’s because it is one of the few supplements that directly accelerates muscle growth, improves performance, reduces muscle damage and soreness, and boosts anaerobic endurance (19, 20, 21).

 But, creatine doesn’t deliver any of these benefits acutely. You need to saturate your muscles either through a loading phase or by taking the standard five-gram dose daily for three to four weeks.

You don’t need to take creatine as part of a pre-workout supplement for it to be effective. A standard monohydrate will do the job. It’s cheap, it’s effective, and it’s safe (22).

B Vitamins

It’s common practice for supplement manufacturers to include B vitamins in their pre-workouts, but the literature hasn’t been able to find any acute benefits.

There’s no doubt that B vitamins are essential - they are involved in numerous biological processes and serve an important role in longevity, cognition, and energy level.

If you can’t get enough of them through your diet, supplementing with them is a good idea. But there is no research out there to suggest that doing so before a workout will acutely improve your performance.

Which Ingredients Have No Performance-Enhancing Benefit for Us

Unfortunately, there are many ingredients found in pre-workouts that do absolutely nothing for us. In most cases, manufacturers include them because these substances are cheap and cut the cost. Plus, having more ingredients with fancy names beefs up the label and makes the pre-workout seem more useful than it is.


Remember citrulline? The amino acid that turns into l-arginine in the kidneys after supplementation.

The reason why citrulline supplementation is effective and l-arginine is not is due to absorption. Citrulline reliably raises l-arginine levels and thus boosts nitric oxide production. But directly supplementing with l-arginine hasn’t been shown to have the same or even similar effects (23).

Plus, if your pre-workout already has citrulline, l-arginine would be a redundant choice.


Though it’s commonly included in pre-workouts, there’s no research out there to suggest that agmatine supplementation improves exercise performance, decreases soreness, or enhances recovery.

Until we have more research, agmatine is staying put on the sideline.


 Another commonly found ingredient in pre-workouts is l-tyrosine. This amino acid is involved in the production of dopamine and noradrenaline.

Research has suggested that supplementing with it can reduce stress, but its effects as a performance-enhancer have not been backed by science (24).

Branched-Chain Amino Acids

Leucine, isoleucine, and valine are three of the nine essential amino acids, commonly sold as a BCAA supplement. But here’s the thing:

You don’t need to supplement with them because you can get enough of each so long as you eat enough protein. In fact, research has shown that dairy protein is more effective at stimulating muscle protein synthesis than BCAA supplementation (25).

As long as you take care of your pre and post-training meals, having BCAAs as part of a pre-workout or as a stand-alone supplement won’t deliver any benefits.

On that note, there is one scenario where BCAAs are helpful. If you usually train fasted in the morning, having a dose of BCAAs beforehand is a great way to offset muscle protein breakdown and stay in the safe zone until your post-workout meal.


Glutamine is one of the twenty naturally-occurring amino acids. It’s commonly found as a stand-alone supplement or as part of a pre-workout. And though it’s widely sold as a muscle and strength builder, the research doesn’t support these claims.

In a few instances, glutamine has been shown to be effective:

Vegans and vegetarians with low dairy and protein intake, for example.

But if your diet is high in meats, dairy, and eggs, you shouldn’t worry about it. Glutamine is also found in very high doses in whey and casein protein.