Nitric oxide (NO) has become a big focus of pre-workout supplementation because of its effect on performance. Increased NO may help with muscle contraction and increased blood flow during exercise; however, it seems these results may be achievable through natural sources as well as supplementation. The ACSM published a new study examining the effect of nitrate-rich beetroot juice on cycling performance at (simulated) altitude.
The researchers conducted this study to see if simply drinking nitrate-rich beetroot juice can minimize the negative effect of high altitude on exercise tolerance, and what they found is promising. They concluded that ingesting (70 mL) beetroot juice reduced the oxygen cost for cyclists at steady-state exercise as well as increasing their time trial performance as compared to a placebo group. However, the researchers are unsure of the mechanism by which beetroot causes these benefits.
One possible explanation may be that because NO is a strong vasodilator, meaning it increases the blood flow to the working muscles. Another strong explanation is that beetroot may increase the efficiency of mitochondrial respiration while decreasing the cost of adenosine tri-phosphate in the muscles. Whatever the cause; however, the results speak for themselves. It is important to remember that this research focused on endurance exercise at high altitudes, and more research is needed to test the effects on both other forms of exercise as well as different altitudes.
That said, beetroot may offer a simple and cost effective way to enhance physical performance. Instead of buying the newest pre-workout NO supplement, it may be worth giving your wallet a break and giving beetroot a shot before your next workout.
Muggeridge, D. J., Howe, C. C. F., Spendiff, O., Pedlar, C., James, P. E., & Easton, C. (2014). A Single Dose of Beetroot Juice Enhances Cycling Performance in Simulated Altitude. Medicine & Science in Sports & Exercise, 46(1), 143-150.