When we lift weights or do resistance exercises, our muscles adapt by changing which genes are turned on or off. These genetic changes (called transcriptional changes) help muscles grow stronger and improve their metabolism. Both young and older people experience these changes, but aging changes how muscles respond at the genetic level, which may help explain why older adults don’t gain muscle as easily as younger individuals. In a study […]
According to the National Institutes of Health (NIH), 68% of households in the United States have a pet. Pets are thought to help people by decreasing stress and improving cardiovascular health. The NIH and Mar’s Corporation WALTHAM Centre for Pet Nutrition have teamed up to support research examining such questions, but the results have been mixed. According to Dr. Layla Esposito, who leads the NIH Human-Animal Interaction Research Program, people […]
Have you ever experienced muscle fatigue? You know the feeling where your muscles start to burn and no matter how hard you try, you simply cannot summon any more strength? It is often assumed that the burning sensation associated with muscle fatigue is due to lactic acid building up in the muscles. But is that the full story? In this time machine post, we examine the science behind muscle fatigue […]
Happy Pigeon Appreciation Day! Okay, I know it sounds strange to celebrate pigeons – the animal best known for gathering in large numbers, causing a raucous, as well as perching and pooping on just about everything. For just a moment though, I would like to consider the unique athletic attributes of these popcorn and park loving birds vs humans engaged in endurance exercise. Have you ever heard of pigeon racing […]
In todays’ Time Machine, we are taking a look back at a paper written by Dr. Henry Gray Barbour during his time in the Department of Pharmacology at Yale University School of Medicine. Published in Physiological Reviews in 1921, his paper examined how body heat is regulated in various species. In this review, Dr. Barbour explains that water is the best medium for conducting heat throughout the body. This is […]
A reference to nectar-feeding bats as “hummingbirds of the night” in a presentation at the 2025 American Physiology Summit in Baltimore last month caught my eye. What an appropriate nickname for bats that can have blood sugar levels exceeding 750 mg/dl after a meal! Sure, a hummingbird would think this was normal, but for a human these levels would warrant a trip to the emergency room. New research shared by […]
Humans and racehorses have something in common when it comes to risk of sudden cardiac death. In fact, sudden cardiac death is the 2nd most common cause of death during exercise among these athletes. Although rare, it typically affects young, seemingly healthy individuals. Research suggests that exercise itself is not to blame, but rather an underlying predisposition for irregular heart rates that exercise uncovers. The most common inherited causes of […]
We are very excited to share this winning guest blog post from Amy Klink, doctoral student at the University of Nevada – Las Vegas. Amy received the Dr. Dolittle travel award to present this research at the 2025 American Physiology Summit in Baltimore. Congratulations Amy! As a kid growing up in Lake County, Illinois, I spent more than half of my summer in some lake or body of water competing […]
Heat is a major physiological stressor that can damage proteins in the body, promote dehydration and even lead to death. Organisms living in hot environments must develop both behavioral and physiological mechanisms to prevent heat-related damage or illness. A recent review published in Physiology examined how humans and experimental animals adapt to heat (Laitano et al., 2025). Organisms that tolerate heat effectively can maintain normal physiological functions even when […]
Among mammals, humans are known for having exceptional endurance. For example, persistence hunters can run for 2-5 hours to wear out their prey, while marathoners routinely run ~4.5 hours on average (Schulte et al., 2015). Sure, a cheetah can run fast, but it can’t run as long as a human. How did humans develop such exceptional endurance? When vertebrates moved to dry land, they needed to develop lungs to extract […]
Life Lines by Dr. Dolittle 