Unless you’ve been living in a cave for the past hundred years, you know that vegetables are good for you. Plant-based foods are loaded with phytochemicals that work in synergy with each other to reduce oxidative damage and ease inflammation. Veggies are low in calories and rich in vitamins and minerals. They’re also high in fiber, a dietary component that must people don’t get enough of. Whether you work out most days of the week or are sedentary, you can still benefit from the health benefits vegetables offer. Here’s another benefit you may not be aware of: Some veggies may boost exercise performance.
Vegetables and Athletic Performance
Athletes are always looking for the next performance-enhancing supplements. Unfortunately, most either don’t live up to their claims and the ones that do have undesirable side effects. What about vegetables? Some vegetables contain natural chemicals called inorganic nitrates. Dark green, leafy vegetables and beets are among the richest sources of these chemicals.
Are all nitrates created equal? A synthetic form of sodium nitrates and nitrites are used as preservatives in foods, especially processed meats, which some research suggests may be harmful. In fact, you should avoid nitrates and nitrites when it’s a food additive or preservative in foods like bacon. Why are the nitrates in vegetables not thought to be harmful? It’s possible that the natural antioxidants in vegetables change how nitrates are handled chemically by the body.
What makes naturally occurring nitrates in veggies so intriguing is the chemical they ultimately turn into when you eat them. Organic nitrates, from sources like beets, is converted to sodium nitrites and then into a chemical called nitric oxide once it reaches your stomach. It’s nitric oxide that may enhance athletic performance, specifically performance during endurance exercise.
Do Natural Nitrates Enhance Exercise Capacity?
In one double-blind, cross-over study, 5 healthy, young men and women completed a 5- kilometer treadmill run. Prior to the test, each participant ate either 200 grams of beets or a placebo that tasted similar to beets prior to being timed while running on the treadmill. After completing the trial, there was a week wash-out period to remove the placebo or beets from their systems and the process was repeated, this time with each participant getting the opposite feeding. Again, their treadmill times were recorded.
The results? After consuming beets, the participants covered the same distance on the treadmill in less time and with no additional increase in heart rate, suggesting that eating beets lowered their requirements for oxygen during sub-maximal exercise, allowing them to complete the run in less time without an increase in heart rate. Several studies also show that nitrate consumption in the form of beetroot juice improves cycling performance. In fact, one study showed a single dose of beetroot juice improved cycling times.
Some research suggests that the level of training may be a factor in how a person responds to inorganic nitrates. Several studies show highly trained individuals may not enjoy the same performance enhancement as beginners. One reason may be that trained athletes already have high levels of nitric oxide and adding more may not further improve exercise capacity. Research already shows endurance exercise itself stimulates the release of nitric oxide from blood vessels. The release of nitric oxide helps open up blood vessels during exercise to improve oxygen delivery to muscles, so it’s not surprising it improves exercise capacity.
Is Improvement in Performance Entirely Due to Nitrates?
Don’t forget that green, leafy vegetables and beets are rich in other natural chemicals that may work synergistically with inorganic nitrates to enhance exercise capacity. For example, beets contain antioxidants, resveratrol, quercetin and polyphenols, all of which could impact oxygen delivery to muscle tissues and endurance.
Can Inorganic Nitrates from Veggies Improve Your Health in Other Ways?
When you supplement your diet with inorganic nitrates from nitrate-rich vegetables, you may enjoy other health benefits. As mentioned, nitrates are converted to nitric oxide, and nitric oxide dilates blood vessels – and that’s good for your blood pressure. Not surprisingly, research shows, beetroot juice lowers blood pressure. One study showed drinking one cup of beetroot juice daily significantly reduced both systolic and diastolic blood pressure readings in people with high blood pressure. In fact, the reduction in blood pressure was similar to what you’d get by taking a single blood pressure medication. As a bonus, the participants also enjoyed a reduction in arterial stiffness, which bodes well for heart and blood vessels health.
An even more recent study, published in Nutrition and Metabolism, shows inorganic nitrates could help with glucose control and, possibly, lower the risk of some diabetic complications. Reduced availability of nitric oxide appears to play a role in metabolic syndrome, a precursor to type 2-diabetes. Stay tuned for further information on this possible benefit of nitrates.
How Can You Get the Benefits?
As you can see, the form of nitrates used in most of the studies was beets and beetroot juice, but they aren’t the richest sources of nitrates. Swiss chard, beet greens, arugula, kale, spinach, and dark lettuces have even more blood vessel-friendly nitrates. In fact, arugula is one of the richest sources of inorganic nitrates. Don’t forget that if you cook green, leafy vegetables, it destroys some of the nitrates. It’s not clear what quantity of greens you need to eat daily to get the full benefits.
Because most of the research was done on beets, more is known about how much you need to get the benefits with beets than with greens. Based on research, you can enjoy the benefits by eating a few medium whole beets or drinking one to two cups of beetroot juice an hour or two before a workout. You could also whip up a green smoothie using some of the nitrate-rich greens listed above.
The Bottom Line
Can eating nitrate-rich veggies improve exercise performance? It looks encouraging. Regardless, you can still enjoy the numerous health benefits a big bowl of green, leafy vegetables offers. Although high in natural sugars, beetroot juice is another excellent source of inorganic nitrates you can prepare in a home juicer.
References:
J Acad Nutr Diet. 2012 Apr;112(4):548-552.
Sports Med. 2012 Feb 1;42(2):99-117. doi: 10.2165/11596860-000000000-00000.
J Applied Physiol. 2009; 107(4): 1144-1155.
Ann Intern Med. 2001 Jun 19;134(12):1106-14.
Food Chem Toxicol. 2012 Oct;50(10):3646-65. doi: 10.1016/j.fct.2012.07.062. Epub 2012 Aug 4.
J Cardiovasc Risk. 1994 Aug;1(2):173-8.
Medscape Family Medicine. “Beetroot Juice Lowers Blood Pressure in Hypertensives” December 2, 2014.
Nutr Metab (Lond). 2015 May 16;12:16. doi: 10.1186/s12986-015-0013-6. eCollection 2015.
Related Articles By Cathe:
Can Nitrates in Green, Leafy Vegetables Enhance Exercise Performance?
5 Foods that Help Lower Blood Pressure
Can a Single Aerobic Exercise Session Boost the Health of Your Heart?
4 Ways a Vegetable-Rich Diet Can Lower Your Blood Pressure
Is It Ever Too Late to Get the Health Benefits of a Healthy Diet?
A Practical Guide to Essential Dietary Minerals and their Food Sources
