When you push exercise to your aerobic limits, your cardiovascular/pulmonary system improves; it's called the 'training effect'. Your body adapts to the measured stress by becoming more efficient at getting oxygen to the cells, and the cells become more efficient in performing all their various functions. The bottom line is that the perceived effort in climbing a flight of stairs goes down; you don't have to breathe as hard to get to the top, and you recover from being out of breath faster. The best part is that you only need to gradually increase your effort to 20 - 25 minutes per session, and only 3 sessions a week to achieve dramatic, life-changing improvement.

Recently, Laboratory studies have show that even greater benefit is produced by Interval Training - varying the pace over the duration of the training session by pushing into your anaerobic limit (increase output until your breathing can't keep up) every five minutes or so, then throttle down until you catch your breath and your heart rate comes back to it's baseline aerobic rate. According to Dr. Al Sears, measured increases in lung capacity and volume result in laboratory studies. This is exactly what you will experience in most well-run Spinning classes.

On the other hand, marathon-level endurance running is an enormous stress on virtually all the body's organs and systems. In many respects, because it raises cortisol levels dramatically, while suppressing testosterone production, it is a formula for rapid aging. In his new book PACE® - Rediscover Your Native Fitness Dr. Sears shows how lung capacity actually decreases faster in distance runners than in those involved in other forms of exercise. (Find Dr. Sears’ book here)

It is a two-edged sword best used in moderation. The human body is adaptive, and whatever it is called upon to do, it will attempt to modify itself to become more able to accomplish. If that requirement is long-duration, low level stress like jogging, several adaptations take place.

The body will shed all unneeded muscle so as to be as light as possible, and will adapt its energy production systems to get rid of excess oxygen burning capacity. It will adapt to store enough energy (in the form of fat – not glycogen) to have a nearly endless supply of fuel. It will reduce the heart’s muscle structure, lowering its ability to handle sudden demands, like fleeing or fighting an attacking animal (or criminal) – the natural survival mode driving our evolution. It makes this adaption by gradually rebuilding your heart, lungs, blood vessels and muscles as small as possible, while keeping the minimum power output capability required. The typical long distance runner develops the body shape of an 80 year-old in just a few years. This kind of specialized adaptation is now understood to be far from optimal health.

Then what is the best approach to build aerobic fitness while not sacrificing capacity to handle peak demands? As I stated above, whatever you train for the body will adapt toward. So think in terms of what physical activities you are attracted to and want to be doing, and exercise in that manner. Most games (soccer, tennis, etc) require bursts of powerful output followed by periods of less movement. Energetic dancing requires full-out activity for the length of the song, but some rest between dances. Golf, on the other hand requires only that you survive 18 holes without breaking your clubs out of anger or having a (brain-type) stroke – not exactly what I consider a form of exercise. Of course, if you are training for watching TV and drinking beer all evening, your body will also adapt, and as I said before in an earlier article, the ravages of aging will overtake you like a Mongol army – you will live a low-energy life, be tired and in pain most of the time and probably die an early death. The antidote is movement; and if your preferred activities are sedentary, then you absolutely need to take up purposeful exercise as a means of staying fit; exercise that makes you breath very hard for on-the-order of 25-30 minutes 2-4 times a week.

The latest studies on aerobics indicate that the most benefit comes from an activity that involves a sequence of spurts and coasting and might go something like this: Start with a gradual warm-up, and let’s use swimming as an example of a very useful form of exercise, a few laps at a comfortable pace for 5 minutes or so. Then go for a 30 second to 1 minute sprint that seriously taxes breathing rate and heart rate, followed by another 5 minutes of slow pace, comfortable enough to let heart and breathing rates recover to a baseline (a sustainable pace you could do for a longer period if required). Follow that with a sequence of sprints and coasting. You should be able to see your capacity for exercise increase with time, and your fitness will visibly increase with time as well.

The critical key is to not overdo the intensity beyond your capacity to produce energy. There should be a sense of improved energy for life’s many activities, and if you start to feel diminished enthusiasm for living, you are doing too much too often. Too much exercise/physical output is an excessive stress on our adrenal system, which is responsible for controlling our energy production to meet momentary demands. If we live with chronic, excessive stress, the adrenal system will first be over-taxed and become fatigued, leaving us with a sense of not being able to keep up. If we don’t correct the ongoing stress by lifestyle correction, the adrenals will eventually become exhausted and we will feel that way all the time. Pacing yourself at an age-appropriate level of consistent exercise will produce the best potential for a life lived to its fullest and healthiest.

Please understand that exercise alone will fail to make you healthy unless supported by proper nutrition, a healthy sleep pattern, a life situation with reasonable stress levels, with supplements supporting of athletic performance and an attitude of gratitude to go with it. Optimizing fitness during the aging process requires balanced attention to all these aspects of living. We now understand that certain genes promote overall health and longevity, and that exercise, done prudently and not to excess, promotes the expression of those genes. It changes body chemistry to favor strength, endurance and mental solidarity as well as freedom from pain, inflammation, heart disease, cancer and diabetes. It is really a must for a well-lived life. Pick up Dr. Sears’ book here

Good Living - Frank

Author's Bio: 

Frank Wilhelmi of http://www.seniorfitness.com chronicles strategies for staying healthy and fit into advanced age. He is an electronic engineer by trade, but his passion is teaching others to lead healthy, vibrant, pain-free, activity-filled lives.