Nitric Oxide Boosters: They Work!

I've been a big believer in nitric oxide (NO) boosters since their inception.

That's because one of the earliest studies done showed that trained subjects taking an NO-booster for 8 weeks significantly increased their bench press strength. Other studies on NO-boosters also showed that they increased muscle endurance and allowed subjects to train with higher intensity for longer. Sure, some other studies showed that NO-boosters provided little benefit, but in my opinion many of these were flawed studies where they didn't take adequate amounts of the ingredients, or the best forms, or they were done in untrained subjects. These studies showing little benefit of NO-boosters has prompted many scientists to state that NO-boosters are a waste of money. However, most of these scientists never actually step foot in a gym or work with real athletes.

Unlike most scientists, I actually train, every day, like a real athlete.

When I am faced with a supplement that has some studies showing it's effective, but also some studies showing it's not effective, I let the real world be the deciding factor. By real world, I mean what results I get and thousands of other real hard-training weight lifters experience. Personally I have noticed significant boosts in workout energy levels and muscle endurance, as well as strength when using supplements that boost NO levels. And the feedback that I have received from hundreds of thousands of men and women is very similar to my own experience. And if NO-boosters didn't work, they wouldn't be one of the best-selling supplement categories on the market today. Consumers will not buy a supplement that doesn't work and it will disappear. Remember the promise of the supplement GAKIC? The research was impressive, but the real world showed that it didn't work well. And now it's hard to even find GAKIC being sold anywhere. NO-boosters on the other hand have steadily grown into one of the best-selling supplements out there: because they work.

One of the complaints that these other scientists make about NO-boosters is that during exercise NO levels rise on their own.

This is true to some extent. So they claim that NO-boosters offer no real increase in blood flow to the muscles. Yet anyone who trains hard and has taken an effective NO-booster, knows that you can feel the enhanced pump, which is due to increased blood flow. Again, these scientists have rarely set foot in a gym and got a good pump. And you know they surely have never actually tried taking an NO-booster.

Now a brand new study from Gama Filho University in Rio de Janeiro, Brazil shows that one of the most well-known NO-boosting ingredients out there, arginine, does boost blood flow to muscles during exercise.

The researchers gave subjects either 6 grams of L-arginine or a placebo 30 minutes before they performed 3 sets of 10 reps of biceps curls. During the biceps workout they measured the muscle blood volume of the biceps (i.e. how much blood was flowing in the blood vessels located in the biceps muscles).

They reported that the subjects taking L-arginine before the workout increased the biceps muscle blood volume by more than 100% as compared to the group taking a placebo.

Jim's take-home point:

A 100% increase in biceps muscle blood volume is more than a doubling of blood volume! No wonder you feel a bigger pump when you take a quality NO-booster, such as 6 grams of L-arginine. Since arginine tends to be poorly absorbed by the body you could probably expect to see even better results with citrulline, which is why I included it in Pre JYM. 

For more on why I prefer citrulline—specifically citrulline malate—to arginine, read my Supplement Breakdown: Citrulline vs. Arginine.

This greater blood volume with arginine can enhance muscle pump. And a bigger muscle pump is not just important to look big in the gym, but it can lead to long-term muscle growth, as explained in the article I linked above.

The researchers did note that the arginine supplement did not immediately increase muscle strength. But you wouldn't expect a benefit like that from an NO-booster from one single dose. It would take weeks of consistent supplementation to produce a boost in muscle strength.

One note I will make is that the 6 grams dose of arginine is on the high side. And this may explain why other studies saw little benefit with NO boosters. Perhaps you need a higher dose. So when it comes to arginine or citrulline, consider getting in a good 5-6 grams to see better results. I typically recommend 3-5 grams as an efficacious dose, but in light of this study, the dosing may need to increase for best results. Of course, they did not test lower doses in the study, so it's hard to say. But if you can afford it, and you want to be safe, take a dose closer to 6 grams.

Reference:

Alvares, T. S., et al. Acute l-arginine supplementation increases muscle blood volume but not strength performance. Appl Physiol Nutr Metab. 2012 Feb;37(1):115-26.

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