I have always been one to chase, whether that is my future self, my alibis, my goals, or the pump, which is probably the most addictive, as you can do so with a few intense sets of bicep curls, and the others mentioned will take a long time to hunt down the chase.
Like Arnold said to a journalist in the iconic and inspirational docudrama, which helped bring bodybuilding mainstream, “It’s as satisfying to me as, having sex with a woman and coming. And so, can you believe how much I am in heaven? I am like, getting the feeling of coming in a gym, I’m getting the feeling of coming at home, I’m getting the feeling of coming backstage when I pump up when I pose in front of 5,000 people, I get the same feeling, so I am coming day and night.!”
I am not sure how true this was for him, but I get the point. It is one of the reasons now, even though I am retired from bodybuilding and focusing on cycling as my main sport, devoting many hours on the bike and off the bike to being stronger, fitter, and more efficient, and of course to go faster, potentially win races, sacrificing lifting weights with my upper body—although I love it—and it is the reason that I sometimes can’t help myself when demonstrating to a PT client how to do a chest exercise or a curl, doing a little more than needed, as the pump is to die for.
Since I have been working in the industry for over two decades, have competed on many bodybuilding stages, and was aiming to look my best at peak events—dry, vascular, and pumped—a huge influence has been on maximizing the “PUMP,” as well as building muscle through different stimulants of hypertrophy. The pump alone will only increase cell volume, but if you want strong, dense, lasting muscle, you need to combine mechanical overload, and metabolic stress, with sarcoplasmic hypertrophy, which you get from essentially pumping the muscle. This topic is for a later article, where I can break down the different training styles that will deliver the desired look.
Instead, for this article, I am going to expand on a question I was asked after my latest article, where I shared my experience, some science studies, dosages, timings, etc., on a supplement that has gotten a lot of interest and delivered positive results, Creatine Monohydrate. If you want to check that article out, I will put a link to it at the bottom of this page.
This article is related to L-Arginine and can be used for improving performance, more specifically, endurance, since it can increase blood flow via vasodilation, increasing nutrient-rich blood to the muscle and helping clear the blood of hydrogen ions, which can make the muscular environment too acidic to continue.
I have used this supplement in my pre-workout stack for weight training sessions for years, and it delivered what I needed every time, but I have never looked at it from an angle of pure performance, and most specifically, cycling performance.
L-arginine plays a vital role in various bodily functions. It is considered a non-essential amino acid, which means the body can produce it under normal conditions, unlike essential amino acids, which you must ingest. However, supplementing with it can aid in many ways when it comes to performance.
L-arginine is commonly used for improving blood flow and creating that famous “pump” effect Arnold was referring to. This is due to its role in producing nitric oxide (NO), a molecule that relaxes and dilates blood vessels, enhancing blood circulation, leading to that “SWOLE” look often referred to in the bodybuilding community.
When you consume L-arginine, whether through food or supplementation, it enters your body and gets converted into nitric oxide by an enzyme called nitric oxide synthase. Do you remember NO EXPLODE by BSN? Well, among many ingredients, it contained L-arginine. However, the problem with many pre-workout blends—not all, though—is that they list a combination of different ingredients as proprietary blends and do not provide specific dosages per serving, so it’s hard to know if you are getting enough to deliver the results or if you are being falsely led. Some companies will do this to reduce the costly ingredient and fill the weight with others, some will do it to keep their formula to themselves, and some for various other reasons. However, making your own blend of specific ingredients will not only save you money but also allow you to test the formula, adding in new ingredients over time, and testing what works and what doesn’t, regardless of the studies, as we will not all respond the same way. So many factors affect the process.
Back to the ingredient mentioned, when L-arginine is converted to nitric oxide, it acts on the smooth muscle cells of blood vessels, causing them to relax and widen, known as vasodilation. When your blood vessels dilate, the blood flow through them increases. With wider blood vessels, there is less resistance for blood to flow through; therefore, oxygen and nutrients can reach your muscles quicker. This is particularly beneficial during high demand, as it can help improve endurance and performance by delivering more oxygen to muscles and removing metabolic waste products.
The use of L-arginine to enhance blood flow and performance has been studied extensively, but the findings are somewhat mixed. While L-arginine is widely known for its role in nitric oxide production and blood flow, the effectiveness of supplementation in improving blood flow during exercise or in general physiological conditions has been debated.
Some studies do show that L-arginine supplementation improves blood flow and nitric oxide levels, leading to enhanced vascular dilation, and increased blood flow. However, other studies have found limited or no effect, especially in healthy individuals who already have sufficient nitric oxide production.
A published paper in the Journal of the International Society of Sports Nutrition (2017) analyzed several studies on L-arginine supplementation. It found that L-arginine supplementation may have modest effects on exercise performance, but the improvements in blood flow were not universally significant across all studies.
Another systematic review (2013) also concluded that while L-arginine could increase nitric oxide and enhance vasodilation, the results were inconsistent across different populations and conditions. It suggested that L-citrulline might be more effective for boosting nitric oxide levels and blood flow over time.
The difference in how “pumped” someone feels during a workout, even when using similar supplements like L-arginine, can be attributed to a variety of physiological, genetic, and environmental factors.
Personally, I’ve gotten tremendous pumps—sometimes too intense, where my arms feel like they are going to explode. I keep mentioning the arms because the muscle shape is narrow at both ends and large in the centre, which is called the belly. So, blood flows in and almost pools. It has a fusiform shape, whereas the quadriceps have a bipennate shape and cross striations, like a feather, so they do not have the same pooling effect or the same pump feeling. That said, just because biceps are the same type of muscle does not mean they can’t get pumped. In fact, the legs are huge, so when they do fill, they swell, and if you’ve got big legs like me, they look enormous.
Many factors will contribute to the pump, or lack of it, that can be described from person to person. One of the reasons the results of the studies may vary is due to individual differences.
Some people are just genetically more vascular, or maybe they have created a high demand for oxygen and blood flow over the years, so as a result, their bodies have produced more capillaries. People with more visible or prominent veins tend to feel a stronger pump. People with better cardiovascular health typically have more efficient blood circulation, which means their muscles may fill up with blood more quickly during exercise, leading to a stronger pump. Those with poor circulation or vascular issues might not experience the same effect.
This is also true if someone has more body fat, as their veins are more hidden, and the body fat acts as a layer of separation from the muscle and skin. So, achieving that jacked, skin-wrapped look and feel may not be as strong as someone with sub-10% body fat.
Individuals with a higher proportion of fast-twitch muscle fibres (which are used during explosive, high-intensity exercises) might experience a stronger pump, as these fibres tend to increase in size and engorge blood more rapidly during resistance training.
Some people naturally have a higher density of capillaries (tiny blood vessels) in their muscles, which allows more blood to be delivered to the muscle fibres during a workout, contributing to a better pump.
Staying well-hydrated is crucial for achieving a full muscle pump. Water helps fill the muscle cells, increasing their volume and making them appear larger. Dehydration, on the other hand, can limit the blood flow to muscles, reducing the pump effect.
Proper levels of electrolytes (like sodium, potassium, and magnesium) also help maintain fluid balance in the body and support muscle function. Without the right electrolyte balance, muscles can feel less full or more fatigued during a workout, which is why many pre-workout mixes, like the one I mentioned above, contain a lot of these ingredients too.
Larger muscles naturally have more capacity to store blood, so individuals with more muscle mass might experience a more noticeable pump. Additionally, people with a greater muscle cross-section will have more blood vessels to fill with blood.
And of course, as mentioned, the muscle you are training, the type of exercise, the reps, the rest period, etc., will all lead to a higher pump—or not so much.
Although L-arginine can work for most people, its effectiveness can vary depending on individual factors such as genetics, diet, hydration, and overall health. Many people use it for enhancing blood flow, improving exercise performance, and achieving a better muscle pump during workouts, but as mentioned, results may differ.
L-arginine can also be beneficial for improving endurance, including in activities like the ones I am doing a lot now—road cycling—especially if racing, combining anaerobic and aerobic periods. The need is to sustain effort for long periods and maintain energy and oxygen delivery to muscles, as well as deliver glycogen-rich blood to the demanding muscles and clear lactate, and that acidity, of course. Enhancing blood flow and oxygen delivery can be especially advantageous for athletes like cyclists who are working at high intensities over extended periods.
L-arginine supplementation has been extensively studied for its potential to enhance endurance performance in athletes. A systematic review and meta-analysis published in the journal Frontiers in Physiology in 2020 evaluated the effects of L-arginine on both aerobic and anaerobic performance. The study found that L-arginine supplementation resulted in a mean increase of 0.07 L·min?¹ in VO? max compared to a placebo, indicating a positive effect on aerobic capacity. However, the authors noted that further studies are needed to confirm these findings and understand the underlying mechanisms.
Another systematic review published in Nutrients in 2022 examined the effects of L-arginine supplementation on endurance performance. The review concluded that L-arginine supplementation could support prolonged physical exertion, reduce muscle fatigue, and expedite post-exercise recovery. The mechanisms proposed include increased nitric oxide production, leading to improved blood flow and oxygen delivery to muscles.
Additionally, a study published in the European Journal of Applied Physiology in 2012 investigated the effects of L-arginine supplementation on carbohydrate oxidation during endurance exercise. The researchers found that L-arginine supplementation likely increased exogenous carbohydrate oxidation during endurance exercise, suggesting a potential benefit for endurance athletes.
While these studies suggest potential benefits of L-arginine supplementation for endurance athletes, it’s important to note that results can vary among individuals but it’s fair to say that L-arginine’s positive results in endurance are generally considered more significant and reliable than its effects on just the muscle pump. L-arginine’s ability to improve oxygen and nutrient delivery means that muscles have more resources available to keep working over longer periods. This helps reduce fatigue and can extend the time an athlete can perform at higher intensities without tiring. This is particularly important for endurance athletes who must maintain a consistent pace during long events.
Beyond enhancing performance during exercise, L-arginine also helps with recovery by promoting better circulation. This aids in clearing out metabolic waste products, such as lactic acid, that build up during exercise, reducing muscle soreness and accelerating recovery time between intense efforts.
L-arginine’s effects on blood flow and nitric oxide are helpful not only for aerobic endurance (e.g., long, steady efforts) but also for activities that require interval training or anaerobic efforts (e.g., cycling sprints or HIIT). The improved circulation can enhance performance during both high-intensity bursts and prolonged, steady efforts.
While the pump effect from L-arginine is appealing for aesthetics and bodybuilding, the endurance benefits are more impactful and widely researched in the context of sports and athletic performance. Additionally, the increased blood flow to your leg muscles can lead to better pedal stroke power and more effective muscle contractions. This can result in a more efficient pedal stroke, helping cyclists conserve energy and improve performance during long rides.
Sounds good, right? A lot of bang for your buck, with so many reasons to include this in your pre-workout stack. But when is the best time to take it, and does it vary for the purpose of blood flow versus increased endurance performance?
Dosage: For weight training and any endurance workout or race, the optimal dosage of L-arginine is typically 3–6 grams per day, taken 30–60 minutes before your workout. This timing allows for the peak effects of nitric oxide to coincide with the intense blood flow demand of weightlifting, promoting enhanced vascularity and muscle pump.
However, since it is safe, and an event, race, or even cycling or any endurance-focused session may last a lot longer than a gym session, you can add another dose mid-ride for long durations like 2-plus hours.
Frequency: Take L-arginine daily to build up consistent nitric oxide levels for enhanced blood flow. For those training only on specific days, supplementation on workout days is still beneficial, especially if you aim to maintain vascularity and support muscle recovery.
L-arginine should be taken daily to support long-term endurance, although it can also be taken only before key rides or races for an immediate performance boost.
Combining this supplement with others like BCAAs, glutamine, and creatine during weight training sessions, and carbohydrates, creatine, and electrolytes during HIIT cardio sessions or smash rides, for example, can be beneficial. However, for low-intensity, steady-state sessions, you most likely only need to combine it with water, and some electrolytes—but this will depend on many factors too, including individual needs.
L-arginine works well when combined with other performance-enhancing supplements as well, like L-Citrulline, which is known to enhance NO production even more effectively. Beta-alanine, which helps buffer lactic acid, reducing fatigue and increasing endurance during high-intensity efforts, and good old-fashioned beetroot juice or powder, which is rich in nitrates, may provide an additional boost to NO levels, further enhancing endurance.
I already mentioned creatine, and I have put together another article, just like this one, so I thought it would be good to explain the synergy of using both. L-arginine and creatine are often combined to create a potent performance stack, as they target different aspects of physical performance. Creatine enhances ATP production, which provides muscle energy for short bursts of power during explosive efforts like sprints or lifting. L-arginine, by boosting nitric oxide levels, improves blood flow, enhancing the delivery of oxygen and nutrients to muscles, which is beneficial for both endurance and recovery. When used together, they provide a combination of improved power and enhanced oxygen delivery, helping you push through both strength-based and endurance-based exercises with better results.
This combination of supplements supports both strength and endurance, ensuring you can perform at a high level across multiple modalities of exercise.
If you’re considering taking both L-arginine and creatine for a combined effect, then check out the article on creatine to learn more.
Now, as you can see from the above, there are many benefits to using this product and combining it with several others. The list goes on, and as I mentioned in previous articles, blogs, or even posts, I am a big believer in marginal gains, especially when you have been around the block and know there is no substitute for hard work and discipline.
I believe in the 4 pillars for optimal peak performance and results:
They are all important, however, if 1, 2, and 3 are not in place, then supplements should not be considered, as they should supplement the others. With proper understanding, we can make the best decision moving forward. By using this supplement, we may find that our training improves more than it would without it.
After spending time looking at this supplement from a different angle, I am going to add L-arginine back into my supplement stack, as a pre-workout, not only for my strength and conditioning sessions but also for my cycling sessions.
If you liked this article, please let us know by dropping us a message and tagging us on Instagram. Your feedback helps us continue creating content that benefits your journey. We’d love to hear your thoughts or experiences with L-arginine, and how you’re implementing it in your training, whether for strength or endurance.
And if you’re curious about the combination of L-arginine with other performance-boosting supplements, don’t forget to check out the article on Creatine, where I dive deeper into how it can synergize with L-arginine to maximize both endurance and strength. Click here to read more.
Thanks again for your time, and I sincerely hope this article helps in your decision-making process and supports you in achieving the results you’re working toward.
Let’s keep pushing the limits!