With an increasing number of athletes posting top-level results on plant-based diets, there is growing interest in just how they are able to maintain and even improve strength. The list is long but it’s hard to argue with the achievements of elite triathletes like Richard Roll and Brendan Brazier or UFC fighter Mac Danzig, or even conditioning specialist Jason Ferruggia. Obviously increasing strength on any diet is a complex question but researchers at Sweden’s Karolinska Institute have found at least a partial answer: spinach.
Keeping the science simple, the researchers found the nitrates in spinach produced higher levels of two muscle proteins associated with storing and releasing calcium, a key component in muscle contraction. The study also builds on earlier work at the institute showing nitrates can be converted in the body to nitric oxide (NO), a substance involved in key functions such as blood pressure regulation, immune response and cell metabolism, along with muscle growth.
“The really exciting part is to go
ahead and look at people with
muscle weakness, with muscle
diseases, and even aging, and
see if this can actually improve
their muscle function.”
Andres Hernandez, researcher
The benefits of supplementing to increase NO levels have actually been known to body builders for some time but surprisingly the Karolinska scientists estimate significant improvements can be made by eating as little as 200 to 300 grams of spinach a day. And if you somehow don’t like spinach, high levels of nitrates can also be found naturally in many other leafy vegetables including lettuce and chard, as well as other foods such as beets.
Take-home lesson
The study provides an important clue to how sports people can improve strength without increasing muscle bulk. But even for non-athletes it shows that eating just a modest amount of vegetables daily can deliver major benefits. Personally, I was interested to find this study because it helps to explain why many “scrawny” vegetarians are in fact very strong. Pound for pound some of the most powerful people I’ve seen are yoga practitioners and Chinese martial artists who take few or no animal products but can still perform amazing feats of strength.
It’s important to note here that we talking about naturally occurring nitrates consumed at the levels found in a well-balanced fresh food diet. Many processed meats, for example, use nitrates as preservatives and they are also a core component in many fertilizers. These artificially high levels of nitrates have been linked to gastric and other problems and, of course, cancer. They are also a known cause of headaches, including severe migraines.
Other details and resources
Karolinska Institute English home page
Abstract for spinach study on PubMed