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How well are we equipped to run? - 3. Other equipment April 20 2016, 0 Comments

So far, we have looked at the legs and feet, so it is probably time to look at the other anatomical aids we have for long-distance running.

Let's start with breathing. If you watch fast-running four legged animals you can see that at the two extremes of their stride they either stretch or crunch, and this can have a dramatic effect on their breathing.

If you are at full stretch, it is much easier to breathe in than out, and if you are crunched up, exhaling is the most comfortable option. So breathing is linked to pace, and that is an intrinsic limitation. Cheetahs are astonishingly fast, but they run out of puff pretty quickly. Being bipedal enables us to disconnect our breathing from our pace. We may choose to breathe in time with our stride, but if push comes to shove we can double or triple our respiration rate without affecting our running, a handy trick if you want to maintain a pace for a long distance.

Another thing that you will notice with most animals is that they pant to cool themselves down, and this also has limitations. Running generates heat, and if you are pursued by an animal until you cannot cool down as fast or faster than you heat up, eventually you simply have to stop. If the animal pursuing you happens to be homo sapiens, he has the major advantage of being able to sweat across the full breadth of his skin, and the evaporation of the sweat cools him and gives him many more miles of distance before he overheats. The evidence suggests that we were on a high-protein diet (meat) long before we invented tools and weapons, and that running after animals until they simply lay down from exhaustion was how we caught our food.

Finally, in our necks we have a nuchal ligament, something that his found almost exclusively in running animals. It serves to support the weight of the head without muscular effort, and to hold the head still while running.

So the anatomical evidence is looking pretty strong that we were built to run. In the next instalment we shall look at what we can do that supports the man-as-long-distance-runner theory. In the meantime, you might like to have a look at some of ZEMgear shoes that protect your feet but still allow you to run as nature intended.

 


Keeping cool in the heat July 21 2015, 0 Comments

One of the reasons that we are a successful species when it comes to running is our ability to sweat.

When it evaporates, water takes energy from nearby heat sources to increase the energy of its molecules enough to launch them into the air. The energy used to change the state of the water from liquid to vapour is called the latent heat of vaporisation. When the latent heat is taken from our bodies, it has a cooling effect. In contrast to animals such as dogs who cannot sweat, and have to cool themselves by panting, this means that our whole body surface can be used to cool us, which is why we are so good at running long distances. Dry atmospheric heat is better for us than humid heat, - you are more sweaty in humid heat because the sweat stays on your skin and does not evaporate as easily, so the cooling effect is reduced. Wiping sweat off can be counterproductive, as it can no longer evaporate and cool.

So what does that mean for running in the heat? Essentially, you should aim to expose as much skin as possible to allow evaporation (don't forget to use suncream...), and/or use clothing which wicks the sweat away from your body to the outer surface of the cloth so that evaporation can still take place.

The second part of this story is equally important - because you are losing so much liquid from your skin, you need to drink frequently to restore it. You also lose minerals (notice how your sweat tastes salty), and you will need to replace these. Omission of either of these can result in heat exhaustion; lack of water causes excessive thirst, weakness and headaches; lack of minerals causes nausea, vomiting, muscle cramps and dizziness. So keep drinking, and in hot weather consider upping the amount of salt that you put on your food, or address both with balanced salt drinks.