In two papers published earlier this month in Cell Metabolism and Trends in Pharmacological Sciences, scientists have reported that they have created a blueprint for developing a drug that mimics exercise.  As often happens in health science, research asks more questions than it answers because the body and its reactions are so complex. Here are some questions I have about this research.

In one of the research articles, the scientists wrote that exercise results in a cascading series of more than 1,000 molecular changes, but any one “pill” would affect only a few variables. Does this mean that one would have to take hundreds of “pills” to get all or most of the beneficial effects of exercise?


The human body is a complex framework of interconnected and integrated systems, especially when it responds to exercise and adapts to training. There are many types of exercise. Consider the differences with lifting a heavy weight for a few seconds, sprinting for 1-2 minutes, walking for 30 minutes and jogging for several hours. With different durations and intensities of exercise, different responses are needed. Would one need different “pills” for each type of exercise?

There are many more related questions. For example, the body tries to adapt to the effects of repeated exercise. We call this the training effect. To get the many benefits of exercise, it must be done regularly. Would one have to take the “pills” regularly?

If a system of the body functions adequately, little or no adaptation is needed. Consider the example of blood sugar. If it is high, the person would be diagnosed as having type 2 diabetes. We know that regular exercise helps to control blood sugar by many different pathways, including weight loss and insulin sensitivity. Would one have to take different pills for each desired adaptation to mimic the effects of exercise? Consider what happens if the blood sugar is normal. There is no need to adapt, but exercise would help to keep it normal. Would one need to take the same or a different “pill” to keep it normal?

Let’s assume that after a few decades of remarkable scientific advances, several “pills” could be developed that mimicked just a few of the many therapeutic benefits of regular exercise. Such drugs would have to go through clinical trials to make sure that they were effective, did not have bad side effects and were safe over a long period of time. As a result of the costs to conduct these trials, each of these “pills” would be very expensive.

One of the two scientific papers is a review of previous research, rather than a report of an original study. One reason the co-author of that review article gave for studying “pills” that mimic exercise was that compliance to exercise programs is low. What he did not mention was that compliance to taking prescribed medicines also is quite low. What would compliance be if one has to take hundreds of expensive pills just to avoid having to exercise?

Let’s further speculate that we have a medicine that is inexpensive, cost-effective, has few negative side effects and is able to prevent or treat dozens of diseases and improve one’s quality of life? Would you take it? Well, guess what? We already have that medicine and it is universally available! It is called exercise, and there is no simple way to mimic its effects with a pill.

Readers might think that I oppose research on chemicals that might mimic the effects of exercise. Not true. The research in question is, in fact, very important because it gives scientists insight on how the body works, especially during exercise. As a result, researchers might be able to improve the beneficial therapeutic effects of exercise to treat and prevent many of the diseases associated with our lifestyle, including obesity, type 2 diabetes, cardiovascular diseases, and cancer. All of this will improve the health of our aging population.

In closing, I want readers to realize that taking one or a number of expensive “exercise pills,” no matter how unlikely or far into the future that may be, will probably not bring about the same beneficial effects of exercise. The key is to find one or more types of exercise that you like to do, and do them regularly.

Skinner is professor emeritus at the Department of Kinesiology at Indiana University.