The Physiology of Aerobic and Anaerobic Fitness
The word ”aerobics” is used to describe organisms that consume oxygen and comes from the Greek words for “life” and “air”. For runners, it is essential to know the difference between aerobic (when muscles contract by consuming oxygen) and anaerobic (when muscles contract without oxygen consumption).
Aerobic Efforts
Aerobic efforts appear after 5 or 6 minutes of running and become only aerobic after 10 to 15 minutes depending on exercise intensity. They are particularly economical in terms of energy consumption due to the phenomenon called Krebs Cycle of recycling compounds resulting from the muscle contraction under the influence of oxygen. The anaerobic system will only intervene if you do fast tempo breaks while running or put more effort in at the end of the workout than the aerobic system can take.
For older people, especially for those who have just started running in the second half of their lives, it is advisable to use especially aerobic efforts that do not require too much heart activity.
Anaerobic Efforts
Anaerobic efforts are those that occur without oxygen consumption which means they only use energy substances found in the muscles. Their duration is for 2 to 3 minutes, then the aerobic system gradually begins to take over.
An interesting experiment was conducted a couple of years ago which demonstrates the difference between the two kinds of effort.
Scientists took eight student athletes who were asked to run 100m in normal conditions. After a sufficient time of rest, the same students ran 100m again, this time on the condition that they should only breathe once around the 80m mark. The performance of the first race, when they breathed normally, was almost equal to performance in the second race, when they had “respiratory restriction”.
The Big Difference Between Aerobic and Anaerobic – Recovery Time
Unlike aerobic efforts, anaerobic efforts vary according to their length. It is important to know the recovery time for each type of effort when planning your training schedule.
Efforts in the first 7-8 seconds, also called phosphocreatinic, recover to 80% after only 20 seconds, while efforts of about 40-50 seconds, called anaerobic glycolytic alactacide efforts can largely recover after 2-3 minutes of rest.
When a minute of tough effort is exceeded, we call it intertwined anaerobic glycolytic lactacid effort and the recovery period can sometimes reach up to 72 hours!
Runners need to be familiar with these recovery times because a repeated failure to comply with them may result in severe running injuries and mental exhaustion.
Let’s See Some Real Life Examples
Here are some percentages of efforts in running races
a 100m flat race run comprises approx. 85% phosphocreatinic effort and 15% lactacid glycolytic effort
a 400m race comprises 85% lactacid glycolytic effort and 15% aerobic effort
a 800 m race comprises approx. 55% lactacid glycolytic effort and 45% aerobic effort
from 1500 m and above aerobic efforts dominate almost the entire run
efforts over 60 minutes are 100% aerobic
Why Aerobic Does NOT Always Mean Cardiovascular: The Myth of Aerobic Exercise
Cardiovascular training is essential for everyone. We know cardiovascular training has positive effects on many health factors including blood pressure, cholesterol levels, oxygen uptake, and body composition to name only a few.
However, you might be exercising but not receiving the cardiovascular benefits you desire.
The entire commercial fitness industry wants you to think that ”aerobic” means ”cardiovascular” and they are completely interchangeable. They want you to believe that the only way to achieve a perfect cardiac health is to spend 30 minutes a few times per week on a piece of equipment such as a treadmill.
This is a big lie.
Let’s see the definition of Aerobic exercise first:
with oxygen
moving large muscles rhythmically
sustained for duration of 10-15 minutes minimum
Walking, jogging or cycling are good examples of aerobic exercises.
A cardiovascular exercise is the one that brings the individual into their target heart rate zone and maintains the intensity level for almost the entire workout session. The main objective is to strengthen the body’s cardiovascular system.
Now, if the exercise intensity is below an individual’s target heart rate zone then it is only aerobic and NOT cardiovascular. It will definitely NOT provide the protective gains of cardiovascular training.
This is one of the biggest myths in the industry.
All those people plodding on treadmills at a snail’s pace are doing aerobic exercies, NOT cardiovascular. Burning calories has NOTHING to do with building aerobic capacity or cardiovascular health. There’s a simple test called ”talk test” that can show you when you’re approaching your target heart rate zone. If you are able to talk with the people near you – you are fooling yourself. That’s nothing beneficial for your heart and you’re not even building aerobic capacity.
You’re just burning calories.
The “Threshold”
When running a marathon or any other long run – it is important to know the “threshold” – that moment when you go from aerobic to anaerobic – because the more you run in an anaerobic state, the more you have to be careful to have recovery days in order not to fall due to fatigue or overtraining.
If you do not have modern means to find out when the “threshold” moment is, as high performance athletes do, here is a handy method to use:
Jog easy with a pulse of less than 140 beats per minute to be sure you are in aerobic regime.
Then gradually increase your jogging tempo. When you start panting, become sweaty and your pulse suddenly grows, then you have passed the “threshold”. New Zealand’s famous coach, Arthur Lydiard, says that the “threshold” is reached when you no longer cannot talk comfortably with your running partner – as mentioned above.
Do you want to do cardiovascular training? Wear a heart rate monitor. It’s the only way to tell if the exercise intensity is too low, too high or just right. Do not rely on machines that use hand sensors for heart rate monitoring, they are highly inaccurate.
Building Aerobic Capacity – The Science
Improving aerobic fitness may be a goal for many individuals, from beginners to world-class athletes. Some of the advantages of aerobic fitness are lower blood pressure, lower cholesterol and less risk of obesity, type II diabetus mellitus and cardiovascular disease. Aerobic capability depends mostly on the frequency, intensity and duration of the exercise session.
Frequency
American College of Sports Medicine recommends 150 to 180 minutes of moderate-intensity exercise each week. When starting with running or any other aerobic exercise, you should start out slowly and gradually increase the effort you put in. A good start would consist of 30 minutes of cardiovascular exercise three times a week. When that feels manageable, add in a fourth day and continue like this until you are able to deal with 5 or 6 workouts per week.
Intensity
As David C. Nieman writes in his book Fitness and Sports Medicine: A Health-Related Approach, in order to improve your aerobic fitness, exercise intensity should be between 70-85% of your target heart rate.
To successfully calculate your target heart rate, you must first determine your maximum heart rate, which is 220 minus your age in years.
Multiply that number by 0.7 to determine the lower limit of your heart rate and by 0.85 to determine the upper limit. When starting with running, try to keep your heart rate at the lower end of the target heart rate range. As you get fitter, you should push your limits to increase the upper limit.
Duration
If you are a beginner, aim for 10 to 25 minutes of aerobic running per session. Over time, you can gradually build aerobic capacity and reach 60+ minutes. The golden rule is to never add more than 20% per week to be sure that your body adapts to the stress that is being placed on it.
Let’s say you exercise 20 minutes per session this week. Your goal for the next week should be 24-minute sessions.
Intervals
The rule of thumb for building aerobic capacity is to mix very intense bouts of cardiovascular exercise with periods of recovery. For example, exercise intensely for 1 minute at 85% of maximum heart rate and then recover for 2 minutes at 55% of maximum heart rate.
You should repeat this cycle for the entire duration of your workout. Note that intervals are really not easy and you should be cautious. Get started with short bouts of intense exercises and longer recovery periods. Gradually increase your aerobic capacity.
Why We Need More Sprinting & Weight-lifting And Less Jogging For Building Aerobic Capacity
There is a lot of information here, but to put it in simple terms: anytime you build up anaerobic capacity you build up your aerobic fitness. The opposite is not true! Several long workouts a few times a week are not enough to increase aerobic capacity. That is why you need intervals, sprinting and weight-lifting.
Knowing that, you can CORRECTLY apply cardiovascular conditioning to running.
Building aerobic capacity efficiently requires a bit of pain and suffering. You have to push yourself to the limit in order to get through those very intense exercises.
Doing only aerobic training can decrease running performance.
In un-mature athletes it can initiate a conversion of undifferentiated muscle cells and Type II strength muscles to become type I endurance. An improper training program can rob you of your true potential. Also, many runners start aerobic based fitness programs with no form of physical assessment, and that leads to running injuries and chronic pain.
Every runner who wants to build aerobic capacity should include weight-lifting and sprinting (intervals) in their program.
The issue regarding practising weight training and aerobic exercise on the same day is surprisingly contentious in the sports world.
Many athletes and coaches believe that aerobic exercise, when combined with strength training, can reduce the ability of muscles to grow and strengthen. Conversely, some runners contend that mixing weight training and aerobic exercise blunts the endurance training response. This phenomenon is known as ”muscle interference”. It’s a kind of exercise antagonism.
Scientists from McMaster University in Ontario and the Karolinska Institute in Sweden recruited volunteers to test this idea.
The scientists had expected that endurance training on its own would significantly affect portions of the muscles related to energy production, while resistance training would increase protein synthesis within muscles, the first step toward enlarging the muscles.
The scientists had hypothesized that combined workouts would dampen at least one of the molecular changes. Physiologically, one of the responses would predominate and interfere with the other.
The interesting fact is that didn’t happen. The ”muscle interference” is only a myth.
“Aerobic exercise can precede resistance exercise on the same day without compromising” muscle building, the scientists concluded.
The first study, published in The Journal of Applied Physiology, can be found here.
Many athletes and coaches believe that aerobic exercise, when combined with strength training, can reduce the ability of muscles to grow and strenghten. Conversely, some runners contend that mixing weight training and aerobic exercise blunts the endurance training response. This phenomenon is known as ”muscle interference”. It’s a kind of exercise antagonism.
Scientists from McMaster University in Ontario and the Karolinska Institute in Sweden recruited volunteers to test this idea.
The scientists had expected that endurance training on its own would significantly affect portions of the muscles related to energy production, while resistance training would increase protein synthesis within muscles, the first step toward enlarging the muscles.
The scientists had hypothesized that combined workouts would dampen at least one of the molecular changes. Physiologically, one of the responses would predominate and interfere with the other.
The interesting fact is that didn’t happen. The ”muscle interference” is only a myth.
“Aerobic exercise can precede resistance exercise on the same day without compromising” muscle building, the scientists concluded.
We could say that these findings are important for serious competitive athletes who are designing serious, complicated training regimes.