Spinach boosts muscle strength, just as Popeye always said Research has discovered that the nitrates found in the vegetable boost the production of the proteins in the muscles, making them stronger and more efficient. The researchers, from Sweden's Karolinska Institute, the equivalent amount of nitrate given to the mice in the experiment each day can be found in a small bag of spinach. The same level could also be obtained from two to three beetroots, experts said. "From a nutritional perspective our study is interesting because the amount of nitrate that affected muscle strength in mice was relatively low," researcher Andres Hernandez told the Daily Mail. His team hopes to use the findings to pursue new treatments for people with weak or ageing muscles. The really exciting part is to go ahead and look at people with muscle weakness, with muscle diseases, and even ageing, and see if this can improve their muscle function. The findings are published in the Journal of Physiology. Previous research has credited spinach with fooling our bodies into feeling full, while other studies have suggested it can speed up the recovery of patients who have suffered a heart attack. An earlier one showed that it made them run more smoothly.