What You Should Eat After Exercise

by Carole Jackson, Bottom Line Health

Gym rats are forever comparing notes on the best ways to maximize the benefits of their workouts — whether the goal is to increase endurance, get stronger or simply stay flexible. Doctors, wanting to see their patients use exercise as efficiently as possible, also want to know more. The result? Researchers are kept steadily busy studying what does and does not change the way the body responds to exercise. Sometimes, as with the study I am about to tell you about, they’re surprised at what they learn.

Shaking Up Expectations

In this small study from Colorado State University, 16 sedentary adults (ages 37 to 64) were asked to do 45 minutes of aerobic activity (all at the same intensity) three times a week for six weeks and then, immediately after each exercise session, to consume either a drink packed with protein and carbohydrates or one containing just carbohydrates. Each participant drank the same kind of drink for the whole study.

The results were surprising in three different ways…

Protein drinks weren’t better at building muscle. Both drinks were equally effective at what the researchers were measuring, which was production of new proteins in the muscle (and that leads to the building of muscle). Previous studies had led researchers to believe that the protein drink would have brought greater results.

Protein drinks were better at boosting oxygen intake. Consuming protein increased the maximum volume of oxygen participants were able to use. This oxygen intake is called VO2 max and is a measure of cardiovascular health — the more oxygen your body can use, the fitter you are aerobically and the healthier your cardiovascular system. Lead researcher Benjamin Miller, PhD, told me that the after-exercise protein drink helped boost oxygen volume by increasing the manufacture of proteins in the mitochondria (the cells that produce energy).

Exercise brought new DNA to everyone’s muscles. People in both groups also experienced an increase in the amount of new DNA (the body’s instructions for building living tissue) in their muscle. Dr. Miller called this finding the “coolest of all” because it indicates that exercise helps the body repair old damaged DNA and, he theorizes, the muscle cells likely recruit new DNA from regenerative cells outside the muscle. Dr. Miller said that it was previously thought that skeletal muscle did not replicate at all, noting that this finding may yield new insights on how exercise helps to slow the aging process.

The takeaway message for all of us? It’s helpful for us exercisers to consume protein soon after we exercise — not for building muscles, as we had thought, but to maximize our oxygen intake and build a stronger cardiovascular system.


Benjamin F. Miller, PhD, assistant professor, department of health and science, and director, skeletal muscle laboratory, Colorado State University, Fort Collins.