By Martha A. Simpson, D.O., M.B.A.
Associate Professor of Family Medicine
Ohio University College of Osteopathic Medicine

KEEP EXERCISING UNTIL “SECOND WIND” KICKS IN

Question: For a number of years I’ve played basketball three times a week.  At each session, I notice that the first few times I move down the court I feel winded and like I can’t continue much longer.  However, after a few more minutes, I feel fine.  I continue playing and have much more energy and no longer feel out-of-breath.  After three or four games, I’m always one of the ones who wants to play another game. So, I guess I’m in pretty good shape. I think that the phenomenon I’ve described is what I’ve heard referred to as “second wind.”  Can you explain what causes “second wind”? 

Answer: The expression “getting a second wind” has been used for more than one hundred years. It is generally used to describe the change from breathlessness occurring as a consequence of exercise to a more comfortable and sustainable breathing. This makes it possible to continue exercise just as you describe in your basketball experience. And, you probably know that the term “second wind” is also sometimes used to describe non-exercise activities. As an example, the contractor who was working on a friend’s roof was working in “slow motion” until he got his “second wind” and finished the job on time. Now back to your question regarding exercise.

The regulation of breathing is a complex process that involves interaction between muscles, nerves, blood and lungs -- as well as essentially every other organ of the body. It is no surprise, consequently, that experts in physiology have difficulty determining the cause of “second wind.” In fact, they don’t even all agree the condition exists. Some think it is only a psychological response. Having experienced the phenomenon myself, I’ll vote with the believers.

In the early phases of strenuous exercise, a by-product of metabolism called lactic acid builds up due to an insufficient amount of oxygen in the blood to sustain this level of metabolism. As you continue to exercise this oxygen deficit is overcome, in part, by an increased respiratory rate. In addition to breathing faster, you breathe deeper. Breathing faster and deeper requires the vigorous use of “the muscles of respiration.” These are the muscles between the ribs, those that connect the ribs to the collarbone and spine, and the respiratory diaphragm. Getting all these parts and the nerves that control them accustomed to working at their new, higher level may be part of the “second wind” response. These changes occur rapidly, but not instantly.

The response to exercise, however, is more complex than this alone. It also produces cardiovascular changes. The heart rate increases as well as the amount of blood the heart pumps with each contraction. These improved levels of circulation provide better nourishment for the muscles that move the chest and diaphragm and may make vigorous breathing more efficient.

There are other important changes in our body chemistry that occur with exercise. The liver and kidneys initiate or respond to many of these. There is always a small lag time between the initiation of activity and these physiological accommodations. Perhaps this is part of the “second wind” response, too.

So this phenomenon exists even though research hasn’t “pinned down” the exact explanation for it. My advice is never mind our lack of understanding, just push on through it and play another game of basketball. It really is good exercise.

Family Medicine® is a weekly column. To submit questions, write to Martha A. Simpson, D.O., M.B.A., Ohio University College of Osteopathic Medicine, P.O. Box 110, Athens, Ohio 45701, or via e-mail to readerquestions@familymedicinenews.org. Medical information in this column is provided as an educational service only. It does not replace the judgment of your personal physician, who should be relied on to diagnose and recommend treatment for any medical conditions. Past columns are available online at www.familymedicinenews.org.