Are Nitrates The Secret For Endurance Sports?
Nitrates have become a hot topic in the sports and nutrition realm, thanks to their potential to boost endurance performance. These compounds offer several potential benefits, including improved exercise efficiency, reduced oxygen cost during exercise, enhanced muscle oxygenation, and increased exercise tolerance. These effects are thought to occur through the conversion of nitrates into nitric oxide, a molecule crucial for regulating blood flow, muscle contraction, and mitochondrial function.
The Role of Nitric Oxide in Blood Flow and Vasodilation
Nitric oxide (NO) is a key player in the regulation of blood flow and vasodilation. When nitrate-rich foods are consumed, they are converted to nitrite in the body, which can then be further converted to NO. Nitric oxide helps dilate blood vessels, allowing for increased blood flow to muscles during exercise. This improved blood flow delivers more oxygen and nutrients to the muscles, enhancing their performance and reducing the oxygen cost of exercise.
A Closer Look at the Benefits
Nitric oxide (NO) plays a crucial role in regulating blood flow, oxygen delivery, and nutrient utilization in the body, which can have significant benefits for endurance performance in sports.
One of the key benefits of NO for endurance performance is its role in vasodilation, or the widening of blood vessels. This allows for increased blood flow to working muscles, enhancing oxygen and nutrient delivery during exercise. Improved blood flow can also help in the removal of metabolic by-products, such as lactic acid, which can lead to muscular fatigue.
Furthermore, NO has been found to play a role in improving mitochondrial efficiency, the energy powerhouses of cells, thereby enhancing the body's ability to produce energy during prolonged physical activity. This can contribute to improved endurance and delayed onset of fatigue.
Additionally, NO has been shown to support cardiovascular health by helping to regulate blood pressure and reduce the risk of developing endothelial dysfunction. By promoting optimal blood vessel function, NO can enhance overall cardiovascular efficiency, which is crucial for endurance athletes.
Navigating the Downsides
While acute doses of nitrates have shown promise for those who are otherwise healthy, questions linger regarding their long-term effects and the ideal dosage. Furthermore, the impact of nitrate supplements on individuals with adequate dietary nitrate intake is still unclear. Therefore, it's crucial to approach nitrate supplementation cautiously and with a critical eye toward future research.
Methemoglobinemia Risk
Consuming high levels of nitrates from foods such as beets, spinach, and other leafy greens can potentially lead to methemoglobinemia, a condition where the oxygen-carrying capacity of the blood is reduced. This condition can be particularly concerning for infants and individuals with certain genetic variations that affect their ability to metabolize nitrates effectively.
Potential for Nitrosamine Formation
Another consideration is the potential for nitrate-rich foods to contribute to the formation of nitrosamines in the body. Nitrosamines are compounds that have been linked to an increased risk of certain cancers. While the link between dietary nitrates/nitrites and cancer is still a topic of research and debate, it is an important factor to consider when evaluating the potential downsides of nitrate-rich foods.
Impact on Renal Function
In individuals with impaired renal function, high nitrate intake, particularly from supplements, may further burden the kidneys. Nitrates are primarily excreted through the urine, and excessive intake can potentially worsen renal function in susceptible individuals.
Sodium and Sugar Content
Some sources of dietary nitrates, such as cured meats, may also be high in sodium and added sugars. Excessive consumption of these foods can contribute to health issues like high blood pressure, and increased risk of heart disease and diabetes.
Implications for Sports Performance
While dietary nitrates have been studied for their potential to enhance sports performance, there's a need for cautious interpretation. Some research suggests that individual responses to nitrate supplementation can vary widely, with not all athletes experiencing performance benefits. Additionally, the potential downsides of high nitrate intake, such as gastrointestinal distress, should also be taken into account when considering its use for sports performance.
Finding Nitrates in Your Diet
Nitrates can be found naturally in various foods, including beetroot juice, leafy green vegetables, celery, and radishes. Studies have shown that acute doses of 6-12 mmol (372 - 744 milligrams) of nitrate (usually in the form of a concentrated supplement or juice), typically consumed 2-3 hours before exercise, can improve performance. Nitrates are naturally occurring compounds found in various foods, and they are especially abundant in certain vegetables. Including nitrate-rich foods in your diet can have potential health benefits, particularly for cardiovascular health and exercise performance.
Quantities per Portion
Beets: One cup of raw beets contains approximately 137 milligrams of nitrates.
Spinach: One cup of raw spinach contains around 24 milligrams of nitrates.
Lettuce: One cup of raw lettuce contains approximately 5 milligrams of nitrates.
Radishes: One cup of raw radishes contains about 20 milligrams of nitrates.
Arugula: One cup of raw arugula contains roughly 20 milligrams of nitrates.
Dosage Details
While specific dosage recommendations for nitrates can vary based on individual health conditions and needs, incorporating a variety of nitrate-rich foods into your diet can be beneficial. For general cardiovascular health, including a variety of nitrate-rich vegetables in your daily meals can help support nitric oxide production in the body, which in turn can help promote healthy blood pressure and overall heart health. It is important to note that individual responses to nitrates may vary, and consulting with a healthcare provider or a registered dietitian can help determine the most appropriate and beneficial intake levels for each individual.
Final Words
Nitric Oxide (NO) can be beneficial for endurance performance, but the body's production of NO can be influenced by various factors including diet, exercise, and overall health status. Incorporating a balanced diet rich in nitrate-containing foods such as beets, leafy greens, and other vegetables, as well as participating in regular physical activity, can support healthy NO levels in the body.
While some studies suggest the positive effects of nitrate supplementation on exercise performance, more research is needed to fully understand its long-term implications and identify the populations that could benefit most. Nitrate supplementation holds promise for enhancing endurance performance, but further research is essential to grasp its full potential. Athletes and coaches should approach supplementation with care, considering individual responses and the need for more research. The IOC acknowledges the benefits but emphasizes caution and the need for more evidence in this area.
Hope this helped!
Maria Tanielian
Registered Dietitian/Nutritionniste
ODNQ # 7223, CDBC # 2815, SDA # 949, CDO #16856
References
Hoon, M., Johnson, N., Chapman, P., & Burke, L. (2013). The effect of nitrate supplementation on exercise performance in healthy individuals: a systematic review and meta-analysis. International Journal of Sport Nutrition and Exercise Metabolism, 23(5), 522-532. https://doi.org/10.1123/ijsnem.23.5.522
Jones, A., Vanhatalo, A., Seals, D., Rossman, M., Piknová, B., & Jonvik, K. (2020). Dietary nitrate and nitric oxide metabolism: mouth, circulation, skeletal muscle, and exercise performance. Medicine & Science in Sports & Exercise, 53(2), 280-294. https://doi.org/10.1249/mss.0000000000002470
Kelly, J., Fulford, J., Vanhatalo, A., Blackwell, J., French, O., Bailey, S., … & Jones, A. (2013). Effects of short-term dietary nitrate supplementation on blood pressure, o2uptake kinetics, and muscle and cognitive function in older adults. Ajp Regulatory Integrative and Comparative Physiology, 304(2), R73-R83. https://doi.org/10.1152/ajpregu.00406.2012
Lansley, K., Winyard, P., Bailey, S., Vanhatalo, A., Wilkerson, D., Blackwell, J., … & Jones, A. (2011). Acute dietary nitrate supplementation improves cycling time trial performance. Medicine & Science in Sports & Exercise, 43(6), 1125-1131. https://doi.org/10.1249/mss.0b013e31821597b4
Lansley, K., Winyard, P., Fulford, J., Vanhatalo, A., Bailey, S., Blackwell, J., … & Jones, A. (2011). Dietary nitrate supplementation reduces the o2cost of walking and running: a placebo-controlled study. Journal of Applied Physiology, 110(3), 591-600. https://doi.org/10.1152/japplphysiol.01070.2010
Leal, L., Guimarães, M., Campos, Y., Abreu, W., & Silva, S. (2022). Effect of acute and chronic nitrate supplementation on the performance of endurance athletes: a systematic review. Multidisciplinary Reviews, 5(2), 1-11. https://doi.org/10.31893/multirev.2022009
Macuh, M. (2023). The effects of nitrate supplementation on performance as a function of habitual dietary intake of nitrates: a randomized controlled trial of elite football players. Nutrients, 15(17), 3721. https://doi.org/10.3390/nu15173721
Maughan, R., Burke, L., Dvořák, J., Larson‐Meyer, D., Peeling, P., Phillips, S., … & Engebretsen, L. (2018). Ioc consensus statement: dietary supplements and the high-performance athlete. International Journal of Sport Nutrition and Exercise Metabolism, 28(2), 104-125. https://doi.org/10.1123/ijsnem.2018-0020
Siervo, M., Scialò, F., Shannon, O., Stephan, B., & Ashor, A. (2018). Does dietary nitrate say no to cardiovascular ageing? current evidence and implications for research. Proceedings of the Nutrition Society, 77(2), 112-123. https://doi.org/10.1017/s0029665118000058
