I'm pedalling away on a stationary bike in an exercise studio with a difference. The air inside mimics the air you'd fine at an altitude of around 3,700 metres – the equivalent of being part way up Mount Kilimanjaro. I'm puffing more than I normally would because, as with the air supply in high places, it's harder to get enough oxygen.
But while my lungs feel like they're in Mexico City I'm still in suburban Mosman at Sydney Altitude Training, one of only a few commercial centres in Australia where you can work out in a gym where the air has a lower concentration of oxygen. Why would anyone want to do this? Often because they have a ticket to mountain destinations like Macchu Picchu or Everest Base Camp and want to reduce the symptoms of altitude sickness like fatigue, nausea and headache that can take the gloss off trekking , skiing or sightseeing in scenic places.
On average, 65 per cent of people going to altitudes of 4000 metres or more will have some symptoms of altitude sickness, says Allan Bolton, the Accredited Exercise Physiologist who runs the Centre. You can't eliminate the risk completely but acclimatising your body by working out in low oxygen air beforehand can help you cope much better.
"Reducing the effects of altitude sickness can be the difference between having a fun trip and an okay or even miserable trip," says Bolton. " It can also be the difference between getting down from a summit under your own steam rather than being carried."
How well people cope in low oxygen environments is very variable because some of us are more predisposed to altitude sickness than others, he adds.
"We've had elite marathon runners who don't do well at altitude and less fit people who do fine. Being older isn't always a handicap either. Younger people who are more gung ho are more likely to get into trouble because they want to get to the top of the mountain more quickly. But an older person who's going more slowly is giving their body more time to adjust to the increasingly low levels of oxygen," says Bolton who recently trained a 75-year old client for a trek to Mount Kilimanjaro.
Training in a low oxygen environment is more than just an antidote to altitude sickness though. It also boosts things like physical endurance and speed – which is why altitude training is often used to give athletes an edge when competing at sea level. But non-athletes can get the benefits too – the changes triggered in the body by working out at simulated altitude can help anyone improve their exercise performance or get fitter faster, Bolton says.
Altitude training works by forcing your body to compensate for less oxygen. To do this it raises the heart rate to try and take in more oxygen and circulate it around the body. After a few sessions of this your body learns to use oxygen more efficiently, explains Bolton. The advantage here when you're going for your usual run or bike ride in normal air is that more oxygen reaches your muscles, making it easier to go faster and keep going for longer.
"You also get more of a kilojoule burn – working out at altitude burns 25 to 30 per cent more kilojoules compared to doing the same exercise at sea level," he says.
So how many sessions of altitude training does it take to conquer Mount Kilimanjaro or for weekend warriors to boost their performance or ace the next fun run? Ideally eight to 12 sessions to get ready for altitude and about eight sessions to improve fitness – the more exposure the better. The enhanced oxygen uptake lasts for about four to six weeks after training stops, says Bolton, but you're still left with the improved fitness that's come from being able to work harder.
For any Melbourne readers who want to try altitude training it's available fromBodyology in Notting Hill.
Have you had a brush with altitude sickness?