The research, published in the Journal of the International Society of Sports Nutrition, found the mixture improved the athletic performance of elite taekwondo athletes who underwent endurance, power, balance and agility tests.
“The MaxVO2, lactate, and agility values reached the highest levels after the intake of nitrate and L-arginine, showing a significant difference compared to placebo values,” the authors wrote.
The role of nitrate and L-arginine in athletic performance
Primarily sourced from leafy green vegetables like spinach, dietary nitrate is known to dilate blood vessels and lower blood pressure. Research suggests the compound can also improve exercise performance, reduce muscle fatigue and optimize oxygen consumption.
L-arginine is an amino acid that is found in most protein-rich foods. It is thought to stimulate growth hormone secretion and post-exercise muscle recovery by removing ammonia from the blood during recovery from intense training.
Previous studies have investigated the benefits of nitrate and L-arginine in sports performance, but the results have been inconclusive to date.
Study details
The double-blind, randomized, crossover study, which the authors reported as the the first of its kind, was conducted in 15 experienced male taekwondo athletes.
Eight experimental sessions were held at the same time each day, each separated by 72 hours. During the sessions, the athletes performed a general warm-up for 10 minutes, followed by physical fatigue with Wingate and shuttle run tests, agility tests three minutes later and balance tests five minutes later.
Each participant was randomly assigned to a supplement —nitrate from fresh spinach, L-arginine powder, a combination of both or a maltodextrin placebo—three hours before exercise. The randomization process ensured that each participant was exposed to all four conditions in equal proportions.
The participants were also instructed to adhere to a controlled diet, limiting nitrate- and L-arginine-rich foods, caffeine and other stimulants for 48 hours before testing.
The benefits of co-supplementation
The Wingate test collected data on peak power output and average power during a 30-second sprint. Participants in the combination group reached the highest peak power levels, showing a significant difference compared to the placebo group.
Co-supplementing nitrate and L-arginine also appeared to improve blood lactate levels and increase agility values after the Wingate and shuttle run tests compared to the other supplements.
“The improvement in agility levels among the athletes participating in our study suggests that this is a significant development for sports disciplines that rely on reactive ability for successful performance and for athletes who need to advance their reactive skills,” the authors wrote.
However, while dynamic right balance was significantly higher in the combination group following the Wingate test, there were no significant balance differences across the other supplement conditions after the shuttle run test.
Thus, while the mechanisms of action remain unclear, the authors suggest athletes may use the combination of nitrate and L-arginine to optimize performance and training.
“Further research with larger sample sizes and more mechanistic study designs is required to confirm the current findings,” they concluded.
Source: Journal of the International Society of Sports Nutrition 2024: 22(1), doi: 10.1080/15502783.2024.2445609, “Investigation of the effect of nitrate and L-arginine intake on aerobic, anaerobic performance, balance, agility, and recovery in elite taekwondo athletes”, Authors: Z Kavcı, et al.
