When there's less oxygen in the air, your body responds by creating more red blood cells to carry oxygen through the bloodstream.
Oxygen is as important to running performance as it is to life. One of the physiological characteristics that all great runners share is a high aerobic capacity, which is a fancy way of saying a huge capacity to suck oxygen from the air and deliver it to their muscles, which use oxygen to release energy.
And one of the surest ways to improve your running is to increase your aerobic capacity. Some newer high-tech gadgets actually help you do this without running a single extra step.
Altitude tents are among these devices. As their name suggests, these tents simulate high altitude either by reducing air pressure or by reducing the oxygen content of the air inside them.
Whenever you spend time in an environment with unusually low oxygen content, your body responds by creating more red blood cells, which carry oxygen through the bloodstream. The result is a higher aerobic capacity and the ability to race faster in normal air.
Most altitude tents are designed to be slept in, as research has shown that athletes need to spend at least eight hours a day "at altitude" to experience significant benefits. Two of the leading manufacturers of altitude tents are Hypoxico (www.hypoxictent.com) and Colorado Altitude Training (www.altitudetraining.com). The tents typically cost $7,000 to $10,000.
If money is no object, both of these companies and others can also convert your entire bedroom (or any other room) into a hypoxic chamber. This will probably cost $12,000 to $18,000 and, if used properly (that is, according to the detailed instructions provided by the manufacturer), will lower your PRs by two to four percent.
Intermittent Hypoxic Training
Fortunately, a slightly cheaper and far more practical alternative is emerging: intermittent hypoxic training (IHT). This method is based on the discovery that the stress of adjusting to changes in "altitude" is a stronger stimulus of the desired adaptations in oxygen transport than cumulative time spent at "altitude."
The favored protocol that has emerged from testing with athletes is a series of five-minute exposures to oxygen-poor air (roughly 10 percent oxygen) separated by breaks of equal length. Instead of entering a hypoxic chamber, athletes simply breathe through a mask attached to a portable machine.
Research suggests that athletes can improve aerobic capacity and performance as much through 60 minutes a day of IHT as they can through eight hours of sleep in a hypoxic tent or room. The leading manufacturers of IHT units are Hypoxico and Go2Altitude, an Australian company. Recently their prices have come down sharply, but the units still cost several hundred dollars.
Respiratory Muscle Builders
Some of the muscles that work hardest during running are those comprising the 12 muscle groups involved in breathing. At 85 percent VO2max, these muscles themselves use 15 percent of the oxygen that they draw into the body through their contractions. At this intensity, the diaphragm has been shown to fatigue right along with the working muscles of the extremities.
Running and other forms of endurance exercise strengthen the respiratory muscles, but specific training can increase their efficiency and endurance even further. The old-school way to do this is to breathe through a straw for 30 seconds or so. Today there are some high-tech respiratory muscle training devices that are probably more effective. Two of the best-known devices are the PowerLung and the SpiroTiger.
The PowerLung looks like an overbuilt kazoo. "Load cells" contained within the device increase the muscle work required to inhale and exhale. The level of resistance is adjustable, so you can train your respiratory muscles progressively just as you would your skeletal muscles with weights in the gym. The manufacturer recommends that athletes use it for three to four minutes at a time, twice a day. The PowerLung Sport retails for about $115. For a list of retailers, visit www.powerlung.com.
The SpiroTiger looks and functions rather differently. A short tube extends from the mouthpiece to a bladder that inflates when you exhale and deflates when you inhale. A handheld display monitor provides information about your breathing (rate and volume) and "workout" instructions.
The manufacturer recommends that athletes use it for a full 30 minutes at least every other day for maximum results. The data from these workouts can be downloaded to a PC, allowing you to track your progress. The cost is about $800. For ordering information visit www.spirotiger.com.
Will using a respiratory muscle training device actually improve your running? Possibly. If you do it consistently it will definitely improve the conditioning of your breathing muscles. In studies, sedentary subjects who did this type of training have significantly improved their endurance performance without engaging in any regular form of endurance exercise.
A few studies involving trained athletes have shown a distinct performance benefit. For example, in a well-designed recent study, trained cyclists improved their performance in a time trial by 4.7 percent after completing 20 respiratory muscle training workouts.
Isn't it nice to know you can now improve your running ability by sitting around and breathing, and even in your sleep?