Moderate Altitude Training
I spend my summers in Boulder, Colorado. Part of the reason is the heat where I live in Scottsdale, Arizona the remainder of the year. The average high temperature there from June through August is 108 degrees Fahrenheit (42C). The daily low is around 85F (29C). And to make matters worse, that is also the monsoon season so the relative humidity is often 50 to 60%. It isn’t a “dry heat” then. Training (and living!) is really difficult there in the summer.
This is our third summer in Boulder, but I lived in Ft. Collins just up the road for 30 years (1971-2001). So I am pretty familiar with the area. Of course, the downside here is the altitude. Where I am in Boulder is about 5500 feet (1670m) above sea level. There’s no doubt that when I first arrive the training is difficult due to this altitude. For any given power output my heart rate is a bit higher than it is down in Scottsdale. Within a few weeks, usually about three, things start to get back to what I experience in Arizona.
I’m often asked if I come back to a lower altitude in Scottsdale (about 1,800 feet or 550m at my home there) in better aerobic shape from having spent time at a higher altitude. While there’s no doubt that it feels easier down there after a few weeks in Colorado, I have never believed there was much of an aerobic benefit. A moderate altitude such as in Boulder never seemed to do much to stimulate an increase in red blood cells, it seemed to me. In fact, all it seemed to do was make my training just a slight bit slower. Any benefit I get from being in Boulder is more due to the great training venues and weather than it is to the altitude, I believe.
Until now I’ve really not had much to support that opinion. But today I came across a recent study which addressed this issue [below]. German researchers took seven, under-23, national team cyclists to 6,000 feet (1816m) where they lived and trained for three weeks. At the end of three weeks there was no difference in red blood cell volume, hemoglobin (the oxygen-transporting part of the red blood cells), plasma volume, or hematocrit (the proportion of blood volume occupied by red blood cells). The authors of the study proposed that a minimum of 7,000 to 8,250 feet (2,100-2,500m) is necessary for measurable changes.
At such an altitude I’m certain you would find your power and pace considerably reduced. That can’t be good for performance no matter what happens to blood markers of aerobic fitness. This is when “living high and training low” becomes almost a necessity. The only other way I know to get around this problem at high altitude is to do very short intervals with long recoveries. Something on the order of work intervals of two minutes or less followed by two minutes or more of recovery intervals will allow you keep power and pace high. The intensity of these two-minute-or-shorter work intervals needs to be above anaerobic/lactate/functional threshold. Ten to thirty minutes of total high intensity time within a workout, depending on the intensity, your fitness and your purpose, is probably about all you need two to three times a week.
Such a workout really isn’t necessary in Boulder. But I do allow for two to three weeks for adaptation. After that the altitude isn’t noticeable.
Reference: Pottgieser, T., C. Ahlgrim, S. Ruthardt, H.H. Dickhuth, Y.O. Schumacher. Hemoglobin Mass After 21 Days of Conventional Altitude Training at 1618m. J Sci Med Sport 2008 [epub ahead of print].