Researchers have found that consuming dietary nitrate, the active molecule in beet juice, can increase muscle strength during exercise, and this progress could lead to better exercise supplements.
While previous research has shown that dietary nitrate increases exercise, it remains unclear how the body converts this molecule into the chemical nitric oxide to be used by our cells.
In the new study published earlier this month in the journal Acta physiologicalThe scientists monitored the distribution of nitrate in the saliva, blood, muscle and urine of ten healthy volunteers doing leg exercises.
To better understand the mechanisms at play, the scientists investigated where in the body dietary nitrate molecules are active.
The researchers found a significant increase in nitrate levels in the quadriceps muscle during exercise that involved 60 thigh muscle contractions at maximum intensity over five minutes.
They say that nitrate supplementation led to about a seven percent increase in muscle strength compared to when participants took a placebo.
“Our research has provided a wealth of evidence for the performance-enhancing properties of dietary nitrate, which is commonly found in beetroot juice,” said study co-author Andy Jones, of the University of Exeter in the United Kingdom.
“Excitingly, this latest study provides the best evidence to date on the mechanisms behind why dietary nitrate improves human muscle performance,” added Jones.
Earlier studies had discovered nitrate increases in tissue and body fluids after ingesting labeled dietary nitrate.
But in the new research, the scientists were able to accurately assess where nitrate is increasing and active.
They were also able to shed new light on how nitrate consumed is used by the body to improve exercise performance.
Citing a limitation of the study, the researchers said that while dietary nitrate supplementation usually takes the form of beetroot juice, it’s not clear how the results might have been different had the beverage been consumed by the participants.
Because the research was done in a population of young men, the scientists say more research is needed to determine how women and the elderly respond to the supplement.
“This study provides the first direct evidence that muscle nitrate levels are important for exercise performance, possibly by acting as a source of nitric oxide,” said Barbora Piknova, another author of the study, from the National Institutes of Health in the US.
“These results have important implications not only for the exercise field, but also for other medical fields, such as those targeting neuromuscular and metabolic diseases related to nitric oxide deficiency,” added Dr Piknova.