Published in the journal Nutrients, the randomized crossover trial evaluated the immediate impact of acute dietary nitrate supplementation on physically active men. The data showed distinct increases in peak muscle torque and power output, providing valuable insights into how the ingredient optimizes muscle contractility.
“From a practical perspective, the improvements observed in peak torque and relative peak power were modest, corresponding to approximately 3–4% compared with placebo,” wrote researchers at Poznan University of Physical Education in Poland.
“Although these changes may appear small, improvements of this magnitude could be meaningful in sports requiring repeated maximal force production or explosive lower-limb actions, where relatively small changes in muscle performance may contribute to competitive performance.”
The role of nitrates in sports performance
Dietary nitrates, found in foods such as beetroot and green leafy vegetables, are ergogenic aids that may support sport performance.
Bacteria in the mouth and gut help to reduce nitrates to nitrites and convert these into nitric oxide. Nitric oxide is a potent vasodilator that relaxes blood vessels, optimizing oxygen delivery to muscles. By improving mitochondrial efficiency, the muscles require less oxygen to do the same amount of work, which is valuable in periods of intense exercise.
Although most studies have focused on endurance exercise, nitrate supplementation may also improve muscle power and contraction velocity.
The researchers tested the effects of beetroot juice supplementation on isokinetic exercise - a form of strength training where the muscle contracts and moves at a constant fixed speed - to measure muscle strength at different knee extension angles. They also measured blood lactate to evaluate the metabolic response.
“The improvements in peak torque observed at 60°/s and 180°/s, together with the increase in relative peak power at 60°/s, are consistent with the hypothesis that nitrate supplementation may enhance the force-generating capacity of skeletal muscle,” they wrote.
Study details
The crossover study involved 13 physically active young men who were randomly assigned to consume either nitrate-rich beetroot juice containing 800 mg of nitrate or a low-nitrate placebo in separate experimental sessions.
After a two-hour absorption period, they performed isokinetic knee extension–flexion tests at three different angular velocities. The researchers used electromyography to measure muscle activity and assessed blood lactate concentrations before and after the exercise.
The researchers observed that the nitrate supplementation “significantly improved peak torque, relative peak power, and selected torque angle variables at 60°/s and 180°/s compared with placebo,” they wrote. No significant differences were observed for the 240°/s variable, electromyographic parameters, or post-exercise blood lactate concentration.
“Because the 240°/s condition consisted of a fatigue-oriented protocol, the present study cannot determine whether the absence of significant effects was attributable to contraction velocity, fatigue, or the combined influence of both factors,” they wrote, noting that the physiological mechanisms underlying their findings need to be established.
Source: Nutrients 2026, 18(14), 2377; https://doi.org/10.3390/nu18142377 “Effects of Acute Dietary Nitrate Supplementation on Selected Isokinetic Performance Variables in Physically Active Men.” Authors: J. Jurga et al.
