Why Shouldn’t You Always Be Taking Antioxidants? Especially if you want to build muscle

We are talking about a molecule capable of delaying or preventing the oxidation of other molecules.

A recent study suggests that antioxidant supplements could hamper your muscle-building efforts , because increased oxidation is needed to repair damage to muscle cells (also known as building muscle).

Oxygen is life, right? Pure, healthy and essential. However, inside our body, oxygen is a toxic and reactive gas that likes to bind with other molecules in the body, forming reactive oxygen species (ROS).

ROS are reactive because they are starved for electrons and tend to “steal” them from other molecules with which they come in contact, causing cell damage.

For this reason, ROS must be kept under strict control. The body has a number of ways to do this, and antioxidants from food and supplements are helpful as well.

Since excessive oxidation and ROS levels have been implicated in aging and a number of chronic diseases, antioxidants are held in high regard.

After all, if many diseases are caused by excessive ROS, antioxidant supplements appear to be the ultimate in disease prevention .

This never seemed to work. However, the results of most trials have been mixed, and there is an emerging consensus that some antioxidant supplements may even be associated with increased mortality.


Oxygen is toxic in our bloodstream and forms ROS. Antioxidants help keep ROS in check within our bodies.

ROS are important, but why?

Given its reactive and toxic nature, it is not surprising that there is a connection between high ROS levels and disease.

This is only part of the story, however, as in recent times, ROS have been studied as important signaling molecules. This research revealed that having too little or too much oxidation / ROS can be harmful.

Too many ROS and the result is damage and increased inflammation. With very few ROS, important messages within the cell may not be delivered.

ROS are particularly important signaling molecules during cellular stress, serving as an important ‘running’ signal to initiate muscle growth and recovery after a workout.

ROS are not all bad; They can also serve as important signaling mechanisms within our bodies.

Antioxidants have been shown to negatively impact exercise

While antioxidants in the diet are essential for good health, some studies have suggested that antioxidant supplements may not be as good in the context of your training.

Originally studied as a possible way to prevent muscle soreness and improve recovery, the effect of antioxidants in adapting to exercise has a rough track record.

Previous research in human subjects has shown that high-dose supplementation with vitamin E and C can negate some of its health-promoting effects, particularly on glucose metabolism and insulin signaling.

Other studies have shown that antioxidants can decrease exercise performance or delay recovery.

Although multiple mechanisms have been proposed for why this occurs, the interaction of antioxidants with exercise remains a controversial issue as too much oxidation in the body can be as bad as too little.

Antioxidants are important for good health, but they can also have a negative impact on workouts.

New Study: ROS from Mitochondria Required for Muscle Cell Membrane Repair

A recent study sheds new light on how antioxidants can interfere with muscle building, possibly by suppressing the ability of muscle cells to repair their cell membranes after exposure to heavy load.

Although mitochondria have long been known to be particularly important in the muscle repair process, the mechanism has been a mystery.

The researchers found that following damage to the cell membrane, calcium, which exists in a much higher concentration outside of cells, floods into the cell cytosol.

While calcium is important for healthy teeth and bones, it is also an important signaling molecule and, like ROS, can be toxic at high levels.

After entering the cell through damaged cell membranes, the excess calcium was rapidly absorbed by the mitochondria.

The researchers found that this helped prevent cytosolic calcium from getting too high and killing cells, and it also sent signals to mitochondria to increase ROS production.

Damage to the muscle cell membrane causes calcium to precipitate within the cell. This is taken up by the mitochondria, which triggers increased ROS production.

What the researchers found below has important implications in the gym: Increased mitochondrial ROS production was essential for repairing the membranes of muscles and other cell types after injury.

The mechanism works through ROS activation of the RhoA enzyme, which triggers the formation of actin fibers around the injury site.

In this case, the actin fibers act as a kind of molecular scaffold that helps the cell to patch holes in the plasma membrane. An easy way to think about this is to imagine repairing a large hole in the roof of a house.

The damage cannot be fixed simply by throwing another layer of shingles on top; the underlying beams must be rebuilt first. This is precisely what happens when a cell membrane is damaged.

Actin fibers form around the hole (i.e. the beams), which is then patched by placing more lipid membrane (i.e.

ROS promotes the formation of actin fibers around cell membrane damage (which occurs during exercise). This acts as a scaffold to patch the hole.

The researchers took their studies one step further by isolating intact muscle fibers from mice.

Where they showed that the inhibition of mitochondrial ROS production limited force production during muscle contractions and also paralyzed the ability of muscle fibers to repair themselves.

Preventing ROS levels from rising limited the ability of isolated muscle fibers to repair cell membrane damage, and it also limited force production.

Interesting implications of this research

The main conclusion of this work is that antioxidant supplements around the time of training could have a negative impact on your ability to recover and build muscle.

It is important to emphasize that more research in whole animals and (eventually) human randomized controlled trials (RCTs) is needed to say with certainty that this is the case.

Although large RCTs are the gold standard for determining how a supplement will (or will not) affect muscle growth, basic and more fundamental research like the present study is also important in revealing the mechanisms at work.

The dependence of muscle repair on the mitochondria also suggests that healthy mitochondria might be important for building muscle outside of simply supplying ATP.

It is also interesting that most types of exercises and diets that promote mitochondrial adaptations (resistance training, cardio, intermittent fasting, etc.) do not themselves cause muscle growth.

Could it be that these types of interventions are useful in conjunction with weight training to indirectly promote hypertrophy by “tuning” the mitochondria?

More research is needed to answer this question, as we are still in the early stages of understanding these mechanisms.

What you need to know

Although antioxidants are an essential part of any diet, evidence is mounting that antioxidant supplements should be avoided in the hours remaining around training time.

It may also be wise to avoid antioxidant supplements on a daily basis in very high doses if you are looking for maximum muscle growth.