Hyrox, the fitness craze that runs and runs

Meaning:Cavernous means huge and hollow inside — so big and so empty that a person standing in the middle of it looks small. The word is built straight out of cavern, another word for a cave, and it almost always describes an indoor space. Here it tells you how large Strawberry Arena is: thousands of racers are running laps inside it, and there is still room to spare.

Meaning:To concede is to admit that something is true even when it counts against you. You are not giving up the whole argument — you are handing over one point of it, usually right before you make your own. That is exactly what happens here: the co-founder of Hyrox concedes that his races cost a lot, and then argues that people keep signing up anyway.

Meaning:Solitary means done alone, or standing alone with nothing else around it. It belongs to the same family as solo and solitude. In this sentence it describes working out: most people train by themselves with headphones on, so the writer calls it a solitary pursuit — and turning that alone-time into something people do side by side is much of what makes Hyrox popular.

Read that list again. Rowing and running are on it. So are kettlebells and a sled. Those are two different jobs, and the body does them in two different ways.

People who study exercise physiology — what happens inside the body while it works — split training into two big kinds. Cardio is short for cardiovascular, which means heart and blood vessels. Cardio work is anything you keep doing for a long stretch: running, rowing, swimming, cycling. Your heart beats faster and your lungs pull in more air, because working muscles burn oxygen and need a steady supply of it delivered by the blood. Train that way often and the heart pumps more blood per beat, so the same effort costs you less.

Strength work has the opposite shape: one big push lasting a few seconds, then a rest. Lifting a kettlebell, shoving a sled, dropping into a lunge. Here the muscle has to produce a lot of force at once. Pushing hard against a heavy load causes tiny tears in the muscle fibres, and while you sleep your body rebuilds them slightly thicker — which is why the same weight feels lighter a month later.

Picture a school sports day. The 1,500 metres is cardio: nothing you lift is heavy, you simply have to keep going for four straight minutes. Tug-of-war is strength: twenty seconds of pulling as hard as you possibly can, and then it is over. The kid who wins the 1,500 is often not the kid who anchors the winning tug-of-war team, because the two events ask the body for different things.

That gap is the whole idea behind Hyrox. It puts both kinds into one race, so nobody wins by being good at only half of it. And now, when someone says they are "doing cardio" or "lifting", you know which of the two jobs they mean.

Hy from hybrid. Rox from rock star. Push the two together and you get Hyrox — a word that did not exist until somebody built it.

Linguists, who study how language works, call a word made this way a portmanteau. They borrowed the term from an old French word for a travelling case that opens into two equal halves, with a separate compartment on each side. Two words packed into one container — that is the image. The writer Lewis Carroll gave the word this meaning in Through the Looking-Glass, where he explains that slithy holds both lithe and slimy.

The rule is simple. Take the front of one word and the back of another and join them, so the new word carries both meanings at once. Breakfast plus lunch makes brunch, a meal that really is both. Smoke plus fog makes smog, which is exactly what sits over a city on a bad air day. Pocket plus monster makes Pokemon. Web plus log makes blog.

Notice what the trick buys the people naming things. The company could have called its event "the hybrid rock-star fitness race". Instead they spent one short word, and anybody who hears the story once remembers both halves of it. That is why brands and inventors reach for blends: a portmanteau is shorter than a phrase and it sticks.

Once you know the trick, you will start catching it everywhere — on cereal boxes, in app names, and in words you have used your whole life without noticing they were ever two.