As Arnold Schwarzenegger said, in his own unique way, there’s no better feeling than a muscle pump midway through a workout. You look in the mirror and witness blood flowing to the muscles and bicep veins popping out. You wish you could look this way 24/7.
But muscle pumps and vascularity during a workout can be elusive. Some days are better than others and it can be hard to figure out why.
One of the benefits of pre workout supplements is their ability to increase nitric oxide. You may have seen something to the effect of “Nitric Oxide booster” or “N.O. Booster” on the supplement label or as part of the supplement’s marketing on their website.
Nitric oxide is a molecule in the body composed of nitrogen and oxygen. It’s created from arginine and nitrate (more on those two later) that we consume through diet and supplementation. Nitric oxide, when increased, signals for more blood flow and vasodilation.
But muscle pumps aren’t just a temporary cosmetic effect where you peacock around the gym with your chest puffed out. Blood flow is critical for driving nutrients into the muscle, which can aid in muscle growth.
Most pre workout supplements contain ingredients designed to increase nitric oxide, thus providing better muscle pumps and improved vascularity in the gym. Outlined below are specific ingredients to look for in a pre workout formula, along with specific supplement recommendations that contain these ingredients, ideally in efficacious doses.
Citrulline
We know that the two main ways to increase nitric oxide are the ingestion of nitrates and arginine. Citrulline is the precursor to arginine. When citrulline is consumed, it converts to arginine in the body.
You may think; why not just consume arginine? After all, arginine was a mainstay in the early days of pre workout supplementation. However, citrulline is much better absorbed than straight arginine. Therefore it is considered a more effective way of increasing nitric oxide.
Citrulline has been shown to improve blood flow, but when used chronically rather than acutely. If you received a sample of a pre workout supplement which contained citrulline, you may not notice its effects right away.
Unlike nitrates, it’s rare to find natural foods which contain adequate levels of citrulline. Watermelon is the only food that can be considered to be a quality source of citrulline.
A proper dose of citrulline is 6-8 grams. Most pre workout supplements will have this but some will lowball it or have citrulline as part of a blend where you don’t know exactly what you’re getting.
There are two main forms of citrulline found in supplements; citrulline malate and L-citrulline. L-citrulline is just the regular version while citrulline malate is L-citrulline bound to malic acid. Neither version appears to be superior to the other, but some people hypothesize that malic acid has added benefit in of itself.
In addition to blood flow and pumps, citrulline may have some workout performance benefits in terms of endurance. It makes sense since red blood cells carry oxygen to muscles, so enhanced blood flow should lead to better performance.
Beetroot
Beetroot has one of the highest concentrations of nitrates of any food. As mentioned, nitrates increase nitric oxide levels in the body, leading to better muscle pumps. Beet juice is a popular choice among health enthusiasts as well. It has been shown to have beneficial effects in endurance athletes when consumed pre workout.
For those who aren’t a fan of the juice itself, beetroot powder is sold as an individual ingredient. You may also see beetroot in the form of beta vulgaris on pre workout supplement labels. Dosing beetroot depends on your weight (6.4-12.8mg/kg), but for most people just aim for over 500mg. Be sure to check pre workout labels as this ingredient is commonly underdosed.
Unlike citrulline, beetroot seems to deliver both acute and chronic benefits.
Procyanidins
Procyanidins are a class of flavonoids found naturally in certain plants and foods. They’ve demonstrated excellent results in terms of increased blood flow, in both healthy and unhealthy individuals.
The most likely source of procyanidins that you’ll find in a pre workout formula is grape seed extract. A standard dose is 150-300mg or more, but good luck finding that in a pre workout. It’s commonly underdosed or part of a blend.
Pycnogenol, aka pine bark extract, is another source of procyanidins. It has one of the highest concentrations of procyanidins. An effective dose is in the range of 100-200mg. It is rare to find pycnogenol as part of a pre workout but it is sold as a standalone product at a reasonable price.
Cocoa extract, found in dark chocolate, is high in procyanidins. The higher the cacao content, the higher the dose. The procyanidins in cocoa are not to be confused with theobromine, which is also found in cocoa.
You may see theobromine in pre workout supplements, but theobromine provides a stimulant effect rather than an increase in blood flow.
Arginine
Arginine was a staple in early pre workout supplements like the original N.O. Xplode and SuperPump 250. As supplement research and development evolved, citrulline took its place as the main muscle pump inducing ingredient due to arginine’s poor absorption rate.
But this doesn’t make arginine useless. While you may have to take more to achieve a desired result, it’s still moderately effective in increasing blood flow. This study showed that regular arginine still improved blood flow in exercising, active males compared to placebo.
Nowadays people are wise to the limitations of L-arginine, so there are different forms on the market like arginine silicate inositol (Nitrosigine), arginine alpha keto glutarate (arginine AKG), and arginine nitrate. These are all basically arginine bound to other molecules to help increase bioavailability.
The research is limited on these new forms of arginine. Intuitively you would think arginine nitrate is the best since we know nitrates increase blood flow. But the research doesn’t always reflect things that seem true on principle. Since these different forms are rather ubiquitous in pre workouts, it’s best to try a few different types and see if you find one to be superior.
Agmatine
Agmatine has been around for a few years now, but its effects on muscle pumps still aren’t well understood. It’s a derivative from arginine, but ironically may counteract the effects of arginine and citrulline because of the enzymes it acts on. Although some have said (anecdotally) that combining agmatine with citrulline and arginine gives them better pumps than citrulline/arginine alone. Studies on humans are few and far between, and haven’t shown any clear answers.
Agmatine’s most beneficial effects are in its ability to reduce pain and act as a neurotransmitter. If you’re into the mental focus capabilities of pre workouts, then agmatine is an ingredient to look for.
Pre Workout Supplement Brands
Nowadays pre workout formulations tend to focus on one of two things; increased muscle pumps and workout performance or increased focus and energy through nootropic ingredients and stimulants. Neither one is right nor wrong, it’s just up to the consumer to decide what they value.
This article has focused on supplement ingredients that increase vasodilation, so we’re concerned with the former rather than the latter. The supplement industry is lacking innovation at the present moment, and I haven’t really seen any new compounds that may induce blood flow. So the best bet is to find supplements which contain as many of the ingredients referenced above in adequate doses.
There’s no supplement that features every ingredient on this list, and quite frankly it may be redundant anyway. You could probably only increase nitric oxide so much that it’s capped at a certain point before the body starts to regulate itself. But the supplements below feature some of the best formulations to give pumps in the gym.
Pre JYM
Pre Jym contains clinical doses of citrulline malate and beet root (beta vulgaris). Beyond the pump ingredients it’s a solid formulation. This particular supplement is naturally flavored, which is a plus for anyone looking to avoid artificial sweeteners.
Granite Vaso Blast
If using a two scoop serving as illustrated on the label, Vaso Blast has adequate doses of citrulline, grape seed extract, along with nitrates in the form of arginine nitrate. This is a stimulant free formula, containing zero caffeine.
Granite is the supplement brand of John Meadows, a highly respected figure in the bodybuilding and fitness industry. He’s regarded as a man with a great deal of integrity, so his supplements are likely legitimate.
Type Zero Clean Pre Workout
Another non-stimulant offering here, Type Zero has a somewhat similar pump formula to Pre Jym just without the caffeine. It has a little more beet root and a little less citrulline, along with arginine akg and glycerol.
Glycerol was not something discussed in this article, as there is not a ton of research on it. It works differently than the nitric oxide boosters, as glycerol deals more with muscle hydration. But hydration is important for muscle pumps as well, which is why you’ll find creatine in some of these formulations.