Physical fitness provides an oxygen transport advantage, with bigger hearts, bigger arteries, bigger capillaries, bigger cell-membrane transport capacity, more mitochondria, and more oxygen-combusting enzymes. Research has proven that this fitness advantage does not disappear with age.
Aerobics improves your oxygen levels
Yes, we can retrain our bodies at any age and at any stage in life to use oxygen better, just by doing aerobic exercise. Other good forms of exercise such as yoga or weight lifting provide their benefits by improving muscle strength, balance, and flexibility, but their design doesn’t generate the increase in total body exertion needed to open all the tubes and allow greater oxygen transport.
Aerobic exercise is absolutely necessary to make meaningful improvements in your VO2 Max levels [Ed: our body’s maximum ability to absorb and transport oxygen. For more on this read box]. Aerobic exercise means doing a routine that gets your heart rate up for a prolonged period of time, with activities such as jogging, running, or swimming, bike riding or taking a brisk walk.
How much should you exercise
The amount of rhythmic-sustained exercise necessary to improve the VO2 Max value is, at a minimum, three half-hour periods per week. Four sessions are better; five sessions, best. The exercise must be of sufficient intensity to increase the pulse rate to 70 per cent of your heart’s maximum rate.
You can calculate your personal maximum heart rate by taking the number 220 and then subtracting your age from it. To then get the minimum heart rate training level necessary to improve your VO2 Max level, you multiply your maximum heat rate by 0.7 [70 per cent].
Thus, according to this formula, if your are 30 years old, the formula is: [220 – 30] x 0.70 = 133 heart beats per minute [BPM] exercise level for 30 minutes a day for 3 – 5 days per week. If you are age 50, the minimal heartbeat level to exercise is at 116 BPM, at age 60, 112, at age 80, 90 BPM, and so on.
After sustained aerobic training, you will notice VO2 Max improvements expressed through what you do in everyday life. For example, you will not be easily winded doing simple tasks such as dashing across a busy street to beat a traffic light, or by running up a flight of stairs.
It’s possible at any age
Eminent USC scientist Herbert DeVries took a group of unfit 70-year-olds and showed that they still had the ability to train and increase their VO2 Max. After six weeks of training, their VO2 Max values improved dramatically.
However, proof of the oxygen story derives from the critical research work of Stanford-trained Steven Blair. Surveying the VO2 Max fitness levels of over 10,000 men over a period of years at the Institute for Aerobics Research in Dallas, Texas, Steven Blair showed that fit people had an extremely strong survival advantage. In his article, Physical Fitness and All-Cause Mortality, published in the Journal of the American Medical Association [JAMA] in 1989, he showed some striking perspectives on the role of aerobic fitness in our mortality rates.
Fitness matters most after age 60
The advantage of fitness was not particularly notable until 60 years of age. Causes of death before age 60 were not clearly related to physical fitness. However, after age 60, the participants’ survival rates were closely related to their fitness levels.
Aerobically-fit participants had lower mortality rates from cancer, cardiovascular diseases, and other causes of death. Thus, they had better overall survival rates. A more-recent study from Dr Blair’s group in 2007 looked at 4,060 men and women over the age of 60 for an average observation period of 13.6 years. During this time, 989 members of the group died. However, the fittest portion of the group had only one-third of mortality rate of the least fit. As the percentage of older people in the world population age creeps upward, it is critical to assess those vital predictors of how we will age. Fitness, especially aerobic fitness, is a major key indicator.
Oxygen: breath of life
Of all the many functions that our body performs—digestion, excretion, reproduction, movement, thought, thermoregulation, and sensory awareness—oxygen transport is the most central and critical. Oxygen is the spark that allows our enzymes—the energy-generating catalytic converters inside our cells—to combust food in order to fuel the human machine.
We should be eternally grateful to plants; they are our oxygen source. We exist and thrive only because of the results of their thankless task of converting carbon dioxide into abundant oxygen through the miraculous process of photosynthesis.
What’s your oxygen intake?
Exercise physiologists are able to measure our oxygen consumption. Such measurement is called VO2 Max. The technique for deriving this number involves applying a nose clip, and then placing a mouthpiece connected to a collection receptacle. Then the individual starts on an increasingly-vigorous exercise protocol on a stationary bicycle or treadmill, or merely running around the block.
Our body’s ability to extract oxygen from the atmosphere goes up with each increased amount of exertion until it reaches a maximal value, our VO2 Max level.
This number represents the body’s best capacity to suck oxygen from the air, conduct it through the large respiratory passages to the lungs, then to the heart and big blood vessels, onto the arteries and arterioles, to the capillaries, and across to the cell membranes.
Eventually, oxygen arrives at the tiny mitochondria in the cells, which are our ultimate micro-engines, responsible for generating energy. This multi-step transport system has a functional upper limit, and the upper limit is expressed as your VO2 Max.
VO2 Max reveals your fitness
Your VO2 Max level is measured in milliliters of oxygen extracted per minute per kilogram of body weight.
If your VO2 Max level is high, you will be able to do more strenuous activity for longer, without feeling winded or fatigued.
Conversely, if your VO2 Max level is low, you will become winded with only minimal activity, like walking a few blocks or just walking up a flight of stairs. This value is a wonderfully accurate index of a person’s fitness level.
Ideal VO2 Max levels
An unfit person might have a value of 45ml per minute per kilogram. A fit person may have a value of 80ml per minute per kilogram. So far, the highest value recorded has been with Norwegian cross-country skier Bjorn Erlend Daehlie, with a 96ml per minute per kilogram VO2 Max.
Spot an error in this article? A typo maybe? Or an incorrect source? Let us know!