by Jim Stoppani, Ph.D., Muscle & Fitness
Q I've heard that watermelon juice can be a great natural NO booster. Are there any other common fruits or veggies that can have the same effect?
Short answer: Yes, there are! But first, let's establish why that's a good thing.
If you follow my supplement advice then you likely know that I am a firm believer in the benefits of boosting nitric oxide (NO) levels. Boosting NO levels is beneficial for cardiovascular health since it relaxes blood vessels, allowing them to widen. This keeps our blood vessels functioning properly and prevents them from getting "stiff" as we age. Relaxing or dilating the blood vessels also helps to deliver more blood flow to tissues like muscle fibers.
When you train, your muscle cells create waste products that pull water into them. With greater blood flowing to the muscles, the muscle cells can draw more water into them, resulting in a bigger muscle pump. While some experts feel that the muscle pump has no true physiological significance, it can lead to long-term muscle growth because the muscle pump places a bigger stretch on the membranes of the muscle cells. This stretch signals chemical reactions that instigate long-term muscle growth by increasing muscle protein synthesis.
Relaxing the blood vessels also delivers more blood below the belt—if you know what I mean. That can be beneficial for both men and women. For men it maintains normal sexual function as you age. Translation: better erections. For women it increases clitoral blood flow. Research shows that women experiencing better blood flow to the clitoris have more enjoyable sex and a higher sex drive.
The Other NO Booster ///
The main NO-boosting supplements on the market today utilize the arginine-nitric oxide pathway. That is the pathway where arginine is converted in the body to nitric oxide (NO) with help from the enzyme nitric oxide synthase (NOS), which catalyzes the reaction. Supplements such as arginine, citrulline (which is converted in the body to arginine), and pycnogenol (which increases the activity of NOS) all use this pathway.
This is an effective pathway to target. A recent study reported that subjects consuming arginine 30 minutes before a biceps workout increased biceps blood volume during the workout by more than 100 percent. What's more, research suggests that taking citrulline results in even higher blood levels of arginine and NO than an identical dose of arginine.
Yet there is another pathway that can also lead to higher NO levels in the body: the nitrate-nitrite-nitric oxide pathway. Nitrates are found in many plants. One of the richest sources of nitrates is the beet. When you consume nitrate (NO3-), such as from beets, bacteria in the mouth cause it to lose an oxygen molecule and become nitrite (NO2-). The nitrite then travels to the bloodstream, where it loses another oxygen and becomes NO.
The Power of Beets ///
Supplementing with nitrates, usually by consuming beet juice or taking a beet (beta vulgaris) extract, has been suggested in numerous studies to enhance exercise performance. The purported benefits include greater exercise endurance, greater power output, and less fatigue. This means that during a typical weightlifting workout, it could improve your strength, allow you to complete more reps with a given weight, and allow you to better maintain rep ranges and strength toward the end of the workout. All of this can help increase muscle strength, muscle growth, and muscle endurance.
Consider supplementing by taking about 500 mg of beet extract. Or, look for supplements, such as pre-workout supplements, which provide beet extract along with other supplements, such as arginine or citrulline which use the arginine-NO pathway. One of the best times to use these supplements is 30-60 minutes before workouts. Another ideal time would be about 30-60 minutes before sexual activity to boost your performance.
A recent study found that using an antiseptic mouthwash such as Listerine killed off a significant number of the bacteria in the mouth that convert nitrate into nitrite. This reduces the NO produced from sources such as beets. So if you're using beets or a beet extract product to increase NO levels, consider ditching the antiseptic mouthwash, at least before taking any nitrate source.
Your training partner may not like it—but your muscles will.