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On October 11, 2019, the Kenyan Eliud Kipchoge ran the first sub-two hour marathon. The marathon requires long-term, extreme, energy expenditure. To meet that demand, Kipchoge had some unusual help: precisely calibrated support by a crew of pacers, a bicycle team supplying water and nutrition, and a pair of controversial running shoes that are said to shave a minute off the marathon time. Still, his outstanding run ranks with Usain Bolt’s record 9.58 second 100-meter race, still unbettered after 12 years, and the first 4-minute mile by Roger Bannister in 1954.… Read the rest “Running out of sugar and hitting the wall”

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Three years ago I posted an article called “The Efficiency of the Human Body”, and it has proven to be popular. Then I posted an update last November. I’ve now learned more about the subject, and thought about it, and it’s time for another upgrade. Naturally, upgrades almost always involve an expansion, so there are two pieces now: This one, which explores the distribution of energy use in the resting body (our resting metabolic rate) and the next, which includes the material in the original post by describing energy distribution in the body in motion.… Read the rest “Human Energy: The Body at Rest”

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Nutritional scientists break down energy consumption into three components. The largest is Resting Energy Expenditure (REE), which I’ve examined in detail in the previous post. It accounts for 60-80% of our daily energy consumption. REE is the energy consumed at rest, when there’s no physical activity going on. Another 5-10% is used for digestion. The rest of our energy consumption is due to physical activity. These proportions can vary: if you’re a rider in the Tour de France, your daily physical activity will probably exceed your REE several times over.… Read the rest “Human Energy: The Body in motion”

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A death in Minnesota

The young man arrived in the emergency room in Minneapolis, Minnesota in acute distress, with a fever, rapid deep breathing, and a racing heart. As reported in 2018, doctors couldn’t initially identify the cause of his problem (1). His breath had twice the normal level of carbon dioxide, and that level kept going up. His fever also kept increasing, despite the doctors’ frantic efforts to stabilize him. Forty-five minutes after admission the muscles in his body violently seized up, rigor mortis, but in a body not yet dead.… Read the rest “How DNP (dinitrophenol) kills you”

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Jesse Owens starting the 200 meter race at the 1936 Olympics. Reproduction of photograph in “Die Olympischen Spiele, 1936” p.27, 1936. 

Coverage of the recent victory of the New Zealand team in the America’s Cup yacht race featured sailboats flying along on their underwater foils at ridiculous speed, speeds reaching more than 50 miles (80 km) per hour. Whether it’s running, or driving a car, or sailing these mutant boats, speed is exciting.Read the rest “Speed Limits”