EXERCISE AT HIGH ALTITUDES

It looks like somewhere from Lord of The Rings, right? In fact this is Yemen at the tip of the Arab Peninsular and on the Red Sea.

I’m working here at the moment and realized (a bit too late) that the capital city, Sana’a, is 7,000 feet above sea level. Right at the margin of what is defined as ‘High Altitude’.

What got my attention? Strangely a bit harder to get my breath and my first effort at lat pull downs (for the uninitiated in strength training this is a back exercise where you pull the weight down towards you chest using your latissimus dorsi – those big muscles that run under your shoulder blades) was a disaster. I normally do my work sets at 99 kg (218 pounds) on this exercise. In Yemen up in the mountains I can barely do 60kgs (132 pounds). Shock, horror!

The fact is that at this altitude my lungs and muscles are getting significantly less oxygen than I normally get where I live in Bangkok (which is at sea level). An average person at sea level has about 13-14 kilopascals (kPa) of oxygen in their bloodstream; at 7,000 feet above sea level (asl) they have 8.7 kPa; much lower than this hypoxemia sets in with a number of unpleasant symptoms, even death.

There is obviously a number of risks exercising at this height, especially when you are middle-aged (unless you are used to the altitude and have adjusted – which usually takes 2-3 months and maybe longer). These risks attach to any activity at high altitude, especially climbing, trekking, running or cycling where you are putting your heart and lungs under extra load – remember, with less oxygen they have to work harder anyway just to keep you on the planet. If you have hypertension, be extra careful; also drink more water.

Dehydration is a pet concern of mine and it turns out to be an added risk the higher you go. What happens is that the kidneys command the bone marrow to produce more red blood cells to increase the oxygen-carrying capacity of the blood. To make room for the increased red cells, the body dumps fluid from the blood - excess urine and collection of fluid in the body's tissues are two direct results of these biological actions. Also the mountains in Yemen are very, very dry, with humidity around 30% so you are losing moisture all the time with every breath you take (in Bangkok humidity is usually 80%!).

All this said, there may be some benefits of being at high altitude. Over time the extra exercise needed to breathe and move may strengthen these organs. But the rule is apparently “sleep high, train low” – because at altitude your body works hard anyway, so you get the benefits while resting or doing your normal activity, but you cannot actually train because your muscles don’t get the oxygen they really need. While it may be true that with more red blood cells you get a surge of energy back at sea level (which is why some athletes like boxers or sprinters do train at altitude just before a competition), this doesn’t last longer than a week or so.

I’ll be writing a longer, more fact-based paper for the Fitness Papers when I get the chance. I’m by no means very knowledgeable about this yet, but watch this space – I will be!