Life Lines by Dr. Dolittle

Sponsored by the American Physiological Society

Exercise

Extreme Physiology of Diving

Can you imagine what would happen to your body if you dove up to 1700 meters deep in the ocean for an hour and a half, or experienced months of food deprivation? In the case of deep diving, the high pressure causes the collapse of the lungs of terrestrial mammals (including humans!) and depletion of body oxygen stores, whereas long fasting periods compromise health and induce muscle wasting. Northern elephant […]

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Day 1: Experimental Biology 2021

I attended a really great session this afternoon on the Evolutionary Physiology of Locomotor Behavior: Causes, Consequences, and Mechanisms.   The session started with a talk by Dr. David Raichlin from the University of Southern California who spoke about locomotion from a human perspective. He described how locomotion is not only essential for the survival of species, but also provides benefits for the aging brain. It was fascinating to learn […]

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Surviving the cold

The ability to regulate body temperature is critical for animals. This is especially true for small mammals as they have a larger surface area resulting in more heat loss to the environment than larger animals. Animals that stay active during the winter likewise have to spend more energy to stay warm. To do this well, they need to balance heat loss with heat generation through shivering as well as non-shivering […]

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Scientists discover gene that may protect from hypertension

Giraffes are extreme. Given their long necks, their blood pressure is 2.5 times higher than ours, which ensures that oxygenated blood makes it all the way up to their head. Having high blood pressure, however, is simply a normal characteristic of being a giraffe. A new study published in Science Advances explored the giraffe genome to identify genes that might help protect the cardiovascular system of giraffes by comparing their […]

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How exercise training and diet may impact exercise performance

Both diet and exercise training are associated with muscle performance and endurance. Migratory birds undergo intense endurance exercise. In fact, a recent review indicated that flapping flight costs more energy (9 x increase from basal metabolic rate) than required by elite athletes competing in the Tour de France (4.3 x increase from basal metabolic rate) (Butler, 2016). Unlike running animals, migratory birds fuel endurance exercise with fats as opposed to […]

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Take Time for Activity Snacks

There went another day spent sitting at my computer in virtual meetings with easily accessible snacks in the kitchen nearby. Okay, granted this is not a comparative physiology topic. But it is something many of us can relate to in this age of Covid-19. In a new study published in the Journal of Applied Physiology, researchers explored what happens when people seek out so-called “activity snacks” instead of the salty […]

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Are humans really just upright cats?

Okay seriously, humans are not actually cats. But, humans and cats do share similar nervous system control over how we move from one place to another, i.e. locomotion as described in a recent review article published in Physiology. The ability for mammals to finely control movement depends on two main control systems located in the brain and spine as well as sensory feedback from the skin, muscles, tendons, eyes, and […]

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The evolution of sugar addiction

I have been opening Christmas cards and pondering the science of sugar addiction, admittedly while snacking on sugar cookies – ‘tis the season after all! Excess consumption of highly palatable (i.e. quite tasty) foods as well as sedentary lifestyles are thought to be at the root of the current obesity epidemic. In fact, it is thought that as many as 30% of people living in developed countries are either overweight […]

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Live fast, die young

Researchers have long known that smaller animals have higher metabolisms and tend to die younger than larger animals. Think about it – a mouse typically only lives about 2 years whereas an elephant in the wild may live 50-70 years, depending on the species. After studying over 700 species of birds and 540 species of mammals, scientists discovered that migratory animals also live faster (mature and reproduce earlier) and die […]

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Speaking of space…’Mighty Mice’ stay mighty muscular in space

While we are on the topic of research conducted by astronauts on the International Space Station (ISS), Space X’s 19th resupply mission to the ISS included studies that might help prevent muscle loss in astronauts as well as humans on Earth. While exercise programs have been developed for astronauts, these programs may not be as useful for long-distance space travel – such as a trip to Mars. This is where […]

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