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Sports Nutrition

Don’t Knock NAC

Those of you with goals that include building muscle and strength hopefully have your bases covered with whey protein, creatine, nitric-oxide boosters and branched-chain amino acids. But there’s one supplement you are likely overlooking: N-acetylcysteine. This modified version of the amino acid cysteine is known for its powerful antioxidant properties, but research shows it offers much more for those looking to build muscle and strength and drop body fat.

NAC Notes

N-acetylcysteine is simply the amino acid cysteine with an acetyl group attached to it. Since we only expect those of you with a chemistry degree to know what an acetyl group is, for the rest of you, just know that the acetyl molecule makes the compound more stable (which aids its shelf life) and allows the body to absorb and use it better. In fact, NAC is actually used as a powerful medicine to break up mucus, treat acetaminophen overdose, reduce the symptoms of bipolar disorder and schizophrenia, and decrease hair pulling in those with the compulsive hair-pulling disorder trichotillomania. But let’s get into how this supplement can benefit your body.

Recovery Agent

Unlike many vitamins and minerals, NAC is not your typical run-of-the mill antioxidant. NAC provides its antioxidant benefits directly within muscle cells, where those who train with weights need it most. Not only does it work directly to scavenge muscle-damaging free radicals, but it also boost levels of one of the body’s most critical antioxidants: glutathione. According to research from Victoria University of Technology in Australia, it does that by increasing levels of cysteine within muscles, and because cysteine is required to restore glutathione to its active form, that should explain why NAC was shown to increase levels of activated glutathione before, during and after exercise.

All this antioxidant protection is important for keeping muscle damage under control during heavy training. New studies from Bairro University in Brazil and the University of Oklahoma have shown that muscle soreness and damage are reduced and muscle recovery is enhanced when subjects supplement with NAC before performing eccentric exercise, which is designed to cause severe muscle damage. In essence, NAC can enhance muscle recovery by decreasing the breakdown of muscle membranes and other important muscle-cell components.

Fatigue Fighter

Lactic acid buildup used to be considered the main culprit for fatigue during exercise. New research suggests that lactic acid may instead help muscles to maintain strength and endurance. Now science is focusing more attention on sodium and potassium imbalances in muscle tissue as being the major players in post-exercise muscle fatigue.

When muscles receive the nerve signals to contract, sodium moves into the muscle cell while potassium flows out. As you complete more reps and sets during your workout, sodium levels build up inside the muscle cells, while potassium levels decline. To prevent this problem, muscle cells have sodium/potassium pumps to move sodium out and potassium back in. But during intense exercise, free radicals disrupt these pumps, causing them to become overwhelmed and unable to keep up. This leads to a decrease in muscle strength and muscle endurance, and fatigue sets in.

Research has shown that NAC prevents free-radical buildup, increasing the activity of the sodium/potassium pumps during exercise, which allows muscle strength and endurance to be maintained to delay fatigue. In fact, research from the University of Kentucky Medical Center reported that during repeated handgrip exercise (much like doing reps in the gym), subjects were able to go 30 percent longer when they supplemented with NAC before commencing the exercise. Two studies from Australia also found that subjects were able to perform intense exercise for more than 25 percent longer when taking an NAC supplement before the exercise. And a 1994 study from Baylor College of Medicine in Houston found that subjects taking NAC had increased muscle strength and endurance. So taking NAC can help you to stay stronger for longer in the gym. It also can enhance your ability to tolerate cardio for longer. Research, such as one study done at Kansas State University, shows that supplementing with NAC reduces fatigue of the respiratory muscles, which help you to get in oxygen during exercise. So taking a dose of NAC before cardio workouts also can help make cardio easier, allowing you to train harder and burn even more body fat.

NO Booster

If you’re supplement savvy, then you should be very familiar with nitric-oxide boosters. Most NO-booster supplements work by supplying some form of the amino acid arginine. That’s because in the body, arginine is readily converted to NO with the help of the enzyme nitric oxide synthase. This enzyme controls how much NO is produced in the body. That’s why advanced NO-boosting products also contain supplements that increase the activity of NOS to yield maximal NO production. Studies have found that NAC actually works to increase activity of the NOS enzyme and boost NO levels in the body. This leads to increased blood flow to muscles, which enhances energy levels during workouts, aids muscle strength and growth, and even helps with fat loss. So consider stacking NAC with your favorite NO booster to maximize your NO levels.

Fat Burner

If all these benefits weren’t enough, NAC has yet another trick up its sleeve: fat burning. Sure, you already know that it can enhance fat burning indirectly by allowing you to train harder for longer and by boosting NO levels, but it also can aid fat loss directly. One study from Germany reported in the Journal of Molecular Medicine that subjects supplementing with NAC for eight weeks lost about 5 percent of their body fat without making any changes to their diet. This is even more impressive when you consider the fact that the group taking the placebo gained more than 5 percent body fat over those same eight weeks. The German researchers concluded that NAC aids fat loss by reducing insulin’s ability to interact with fat cells. Normally, insulin reacts with fat cells to increase fat storage and halt fat release from the fat cells. By decreasing insulin’s effects at the fat cell, NAC can make your fat-burning efforts all the more easier, especially if you take it while following a get-lean diet and training program.

NAC Dosing

To gain more energy, blunt fatigue, build muscle, gain strength, strip off fat and maintain better health, consider taking 600 to 2,400 milligrams of NAC per day. We suggest you take it before workouts with your preworkout shake. On rest days away from the gym, take it with your first meal of the day.