Everyone knows that exercise improves health, and ongoing research continues to uncover increasingly detailed information on its benefits for metabolism, circulation, and improved functioning of organs such as the heart, brain, and liver. With this knowledge in hand, scientists may be better equipped to develop “exercise pills” that could mimic at least some of the beneficial effects of physical exercise on the body. But a review of current development efforts, publishing October 2 in Trends in Pharmacological Sciences, ponders whether such pills will achieve their potential therapeutic impact, at least in the near future.
Several laboratories are developing exercise pills, which at this early stage are being tested in animals to primarily target skeletal muscle performance and improve strength and energy use–essentially producing stronger and faster muscles. But of course the benefits of exercise are far greater than its effects on only muscles.
“Clearly people derive many other rewarding experiences from exercise–such as increased cognitive function, bone strength, and improved cardiovascular function,” says Laher. “It is unrealistic to expect that exercise pills will fully be able to substitute for physical exercise–at least not in the immediate future.”
Figure from an earlier 2013 look at exercise polypill
Sedentary lifestyles, limited physical exercise, and prolonged inactivity undoubtedly increase chronic diseases, including obesity, type 2 diabetes, and cardiovascular diseases. It is widely acknowledged that exercise induces a number of physiological adaptations that have beneficial effects in the prevention and treatment of these chronic metabolic diseases. Unfortunately, exercise compliance is extremely low and often not possible. The development of exercise science and molecular techniques has increased our understanding of the molecular pathways responsive to exercise. Knowledge of these molecular targets has led to the development of chemical interventions that can mimic the beneficial effects of exercise without requiring actual muscle activity. This review focuses on the concept of ‘exercise pills’ and how they mimic the effects produced by physical exercise including oxidative fiber-type transformation, mitochondrial biogenesis, increased fat oxidation, angiogenesis, and improvement of exercise capacity. We also review candidate exercise pills, and contrast the beneficial effects and molecular mechanisms between physical exercise and exercise pills.
The signaling pathways of currently described exercise pills are outlined. None of the candidate exercise pills fully mimics the beneficial effects of exercise, but each exercise pill can activate distinct as well as overlapping target transcriptional regulators that can partly mimic the beneficial effects of physical exercise.
SOURCES – Trends in Pharmacological Sciences, Physiology online, Eurekalert