Nitric oxide (NO) is a naturally occurring gas that is known as a vasodilator, meaning it helps open blood vessels and increases blood flow to your muscles. (For the record, nitric oxide has nothing to do with nitrous oxide, which is better known as laughing gas.) Boosting your body’s production of nitric oxide can, theoretically, lead to a better pump in the gym and faster recovery after your workout.  

A recent study in the journal Nutrition looked at the possibility of nitric oxide-promoting supplements leading to increased muscle mass. The researchers concluded that while there is not currently enough research to declare that NO supplements increase hypertrophy, the theoretical basis is so sound that it merits further study. Here are a few things that have been proven about NO supplements. 

• One study found that nitric oxide supplements increased exercise tolerance in untrained or moderately-trained men. This means that it helped guys who were relatively new to the gym better endure the rigors of a workout.  
• A single dose of a NO-boosting supplement helped athletes perform more reps of a high-intensity exercise. Additionally, these same subjects reported 40 percent less muscle soreness two days after the workout, compared to the group who took a placebo.
• Since NO increases blood flow to tissue, it’s no surprise that it’s been used to treat erectile dysfunction. It turns out that NO plays an important role in initiating erections, and one study recently showed that it also helps maintain erections as well.
• When muscle is injured, the body releases something called satellite cells, also known as muscle stem cells, to help facilitate growth and repair. NO activates satellite cells, and studies have shown that when NO is inhibited, muscle repair and remodeling are restricted as well.

Since it’s impossible to ingest nitric oxide itself, most NO supplements supply the materials your body needs to boost its own production. One exciting new entrant to this category is a formulation called S7(link to blend?). Made of seven natural plant-based ingredients, just 50 mg of S7 has been clinically shown to increase nitric oxide levels by up to 230 percent. Research shows that S7 elevates NO levels for three hours, long enough to provide an extra boost to your training and enhance post-workout recovery.