View More

Human energy metabolism, the science behind the energy provided by the food we eat, is a complicated subject. I taught it to science and medical students for more than 35 years, but its intricacies continue to surprise and entertain me. I don’t provide nutritional advice, but I want to blow away some of the cobwebs surrounding it. Much of the material summarized here is described in more detail in previous posts, which are linked.… Read the rest “Body Talk”

View More

Many talented sprinters run like gazelles, their feet barely kissing the track as they glide along. But not all great runners move like this. One of the most successful athletes of all time was a muscular runner named Emil Zatopek, nicknamed ‘The Czech Locomotive’ for his powerful, but not particularly graceful, running. Zatopek won five Olympic medals, four of them gold, and in 1952 he became the first, and so far only, runner to win the 5,000- and 10,000-meter races, and the marathon, at one Olympic Games (it was his first competitive marathon at that).… Read the rest “HIIT, the fitness hack”

View More

You need creatine. For every move you make. But that doesn’t necessarily mean that you need to take creatine supplements. The questions that arise include: does creatine supplementation improve athletic performance? is it safe? how does it work? The answers are, respectively, sometimes, but it depends; probably yes; and, it’s complicated. This post looks at some of the nuances.

Supplements are big business

Supplements are a huge industry; the market in the USA alone is estimated to be over 30 billion dollars a year.… Read the rest “You Need Creatine”

View More

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”

View More

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”

View More

The material in this post has been upgraded and expanded in two posts, which describe human energy efficiency at rest and during vigorous exercise.

I first posted “The Inefficiency of Humans” in January 2017. It’s about the reasons that our energy metabolism provides only about 20-25% of the energy we consume as food for muscular work. I referred to this as our “inefficiency”, although it isn’t really that. The explanation and conclusions remain largely unchanged, but since then I’ve learned more about how energy metabolism is measured, so I’ve rewritten the post as this 2.0 version.… Read the rest “The Inefficiency of Humans”

View More

If, like most of us, you carry more weight than you wish you did, you may have wondered, from time to time, how much that extra poundage affects your health. This has been intensively studied over the past decades. Generally, studies compare health outcomes at different values of Body Mass Index (BMI), which is a useful way to describe body type. BMI is the ratio of weight to the square of height, in metric units.Read the rest “You can eat fat, but don’t get fat”