Nitrates make you faster and stronger
Nitrates Make You Faster and Stronger
May 29, 2011
 by Gabe Mirkin, MD

Drinking a half-liter of beetroot juice before a
time trial helped male bicycle racers ride an
incredible 2.8 percent faster over both 4- and 16-
kilometer courses (Medicine & Science in Sports &
Exercise, June 2011). This is an extremely well-
performed study because all of the bicycle racers
in the study rode faster after drinking a half-
liter of normal beetroot juice (6.2 mmol nitrate)
 than they did after taking the same volume of
beetroot juice that had had the nitrates removed
(0.0047 mmol nitrate). Furthermore, the authors
measured blood levels of nitrates and showed that
the nitrate-rich beet juice raised blood levels of
nitrates from 241 to 575 nm and reduced the oxygen
cost of the exercising muscles. The dose of nitrate
used in the study (6.2 mmol) is 4 to 12 times
greater than what the average person takes in each
day. None of the subjects consumed dietary
supplements.
 
Any food source of nitrates, not just beetroot
juice: Beetroot juice is high in nitrates which
have been shown in many studies to reduce the
amount of oxygen needed to fuel muscles during
exercise and to improve an athlete’s ability to
tolerate high-intensity exercise. How fast you can
race on a bike is limited by the time it takes to
bring oxygen into exercising muscles to turn food
into fuel for contracting muscles. Since nitrates
bring oxygen faster into muscles, eating any food
that is high in nitrates can help you ride faster.
 
How nitrates make you faster: Inorganic nitrate is
converted to active nitrite and, subsequently, to
nitric oxide (Nat Med. 2003;9:1498-505). The most
efficient form of energy for exercising muscles
comes from your mitochondria in muscles which
require less oxygen after a person takes nitrates
(Free Radic Biol Med. 2010;49:S109).
 
Nitrates improve athletic performance: Sodium
nitrate has been shown to reduce the oxygen cost of
cycling (J Appl Physiol. 2009;107:1144-55),
increase power of knee extensor exercise (J Appl
Physiol. 2010;109:135-48), and help athletes run
faster (J Appl Physiol. 2011;110:591-600).
 
How much nitrate before racing? In this study, the
racers were given liquids because liquids pass
through their stomachs and into their bloodstreams
much faster than solid foods do. You can get large
amounts of nitrates from celery, cress, lettuce,
radishes, beets, spinach, Chinese cabbage, endive,
kohlrabi, leeks, parsley and many other vegetables
(Am J Clin Nutr. 2009 Jul;90(1):1-10). Almost all
of the nitrates in vegetables are absorbed into the
bloodstream.
 
Can you take in too much nitrate? Nitrates are safe
and healthful when eaten in vegetables and fruits.
However, nitrates can be converted to nitrites
which can combine with amino acids in foods to form
nitrosamines which are potent cancer-causing
agents. Nitrates (with an A) in plants are
healthful. Too much nitrites (with an I) can be
harmful.
 
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Avoiding nitrites: Bacteria convert the healthful
nitrates to the harmful nitrites in vegetables.
Fresh vegetables are usually resistant to bacterial
infections. However, once a vegetable is cooked,
bacteria reduce nitrates to nitrites. Therefore,
cook only the amount of a vegetable that you plan
to eat right away. Leftovers should be stored for
no more than a day or two in the refrigerator.
Freezing inactivates bacteria, so commercially
frozen cooked vegetables usually have low levels of
nitrites. Pureed foods are much higher in nitrites.
Boiling vegetables reduces nitrate content (Toxicol
Lett. 2008(Oct 1);181(3):177-81).
 
Should you take nitrate pills? Definitely not!
Excessive nitrates in grass and grains have killed
ruminant animals. Bacteria in the stomachs of
ruminant animals rapidly reduce nitrates (with an
A) to nitrites (with an I). Normally, the nitrites
are converted to ammonia to be used by bacteria as
a source of nitrogen, but nitrites can convert
hemoglobin in blood to methemoglobin, which cannot
carry oxygen and the animal can smother to death.
 
In humans, excessive nitrites can accumulate also
and prevent oxygen from attaching to red blood
cells. This is called methemoglobinemia which can
prevent you from even being able to move, and has
killed some infants and adults. This condition can
be caused by drinking very large amounts of stale
juice from cooked spinach or other vegetables high
in nitrates. On the other hand, you should not
worry about nitrates in fresh vegetables harming
you.
 
Should you eat vegetables containing nitrates all
the time? So far, nobody has proven that a high
vegetable diet will make you a better athlete. It
was relatively easy to set up a study in which a
single dose of nitrates is given before a time
trial. However, it takes far more planning and work
to set up studies in which athletes are on long-
term, high-vegetable diets and compare them to
other athletes on low-vegetable diets. We have to
await further research to prove that a high-plant
diet will make you a better athlete. I think it
will.
 
Nitrates help to prevent heart attacks: I recommend
that you eat a high-vegetable diet anyway because
it can prolong your life and help to prevent
certain cancers, heart attacks and many other
diseases. The Mediterranean Diet and the DASH Diet
have both been shown to lower cholesterol and blood
pressure, and help to prevent heart attacks. These
diets are high in fruits and vegetables that are
rich sources of nitrates. Many studies show that
nitrates in vegetables lower high blood pressure.
(Hypertension. 2010;56:274-81). They do this by
widening blood vessels to increase oxygen
availability to muscles. Nitrates also help prevent
heart attacks during intense exercise (Cardiovasc
Res. 2011(Feb 15);89(3):499-506).