Could low iron, protein contribute to soreness after exercise?

Diet and Fitness Expert Dr. Melina Jampolis Physician Nutrition Specialist

Expert answer

Hi Sara. This a very good question, and to get you the most accurate response, I turned to Steven D. Stovitz, M.D., a fellow of the American College of Sports Medicine and an associate professor in the University of Minnesota Department of Family Medicine and Community Health. He's also an adjunct faculty member at the School of Kinesiology, and team physician in the University of Minnesota Athletic Department.

Here is his response along with a few of my nutrition suggestions to supplement his recommendations.

Getting sore after every workout could be due to issues of training or one's diet. Assuming that you are training smart, i.e. with a steady pattern, regular rest and good biomechanics, then dietary deficiencies may be involved. One can certainly be a vegetarian and a high-level athlete.

There are many examples of outstanding athletes who follow vegetarian diets. Some vegetarians, however, are deficient in protein, iron and certain vitamins and minerals, which can be associated with muscle soreness.

Much depends on the type of vegetarian diet that you follow. If you eat eggs (i.e. "ovo") and drink milk (i.e. "lacto"), then you are less likely to be deficient in vitamin D. Vitamin D deficiency has gained attention recently as a common problem. Furthermore, it has been associated with musculoskeletal pain in a variety of research studies. You may want to consider asking your doctor to check your vitamin D (involves a simple blood test) and taking a vitamin D supplement if your levels are low.

You mentioned being low in protein. Muscles need protein, and many vegetarians, especially those who are physically active, are consuming too little protein. The American College of Sports Medicine recommends that endurance and strength training athletes consume higher levels of daily protein than the standard recommended daily allowance (i.e. 1.2-1.7 grams of protein for each kilogram of body weight, versus 0.8 grams per kilogram per day). If you don't eat eggs or milk, it is essential to incorporate some form of protein at all meals and snacks to meet your daily protein requirements. Good options include peas, beans, lentils, nuts and nut butters, seeds, and soy products including tofu, tempeh, and soy milk or cheese. You might consider incorporating a soy protein supplement into your diet if you have a difficult time consuming enough protein. Consuming a fruit and soy protein smoothie before or after working out may help improve your recovery and decrease muscle soreness. Read more on eating to build muscle mass.

Finally, you mentioned being low in iron. Interestingly, vegetarians generally consume as much or more iron than meat-eaters. However, the iron consumed in the vegetarian diet is less well absorbed. Thus, vegetarians are at risk for iron deficiency and this also has been associated with muscle soreness. Your doctor can check for iron deficiency and if you are deficient, you might consider taking an iron supplement. In addition, make sure to eat plenty of vitamin C rich foods as vitamin C improves iron absorption from plant based foods. Try to incorporate some form of vitamin C rich food including tomatoes/sauce, oranges or juice, grapefruit/juice, kiwis, watermelon, cantaloupe, berries, or red or green peppers with most meals and snacks.