When people think of the word “fitness” the mind often goes first to aerobic conditioning. Aerobic fitness gives an athlete the ability to “go” and keep going. This is especially true for endurance sports like running, cycling, swimming, etc. Building up the endurance to go the distance is a primary objective for those athletes newer to athletic training; while more advanced athletes are looking to cover the distance faster.

You can think of Aerobic Conditioning as Two Distinct Elements:  

1. Endurance

2. Speed

Think of these two elements in these defining ways: endurance is the ability to maintain pace while speed is the ability to create pace. To be successful in sport and fitness you need to maximize both endurance and speed through creative training strategies. The shorter an event the larger the emphasis on speed and power will be; while the longer an event the larger the emphasis on endurance will be. However, regardless of the length of the events you are training for, you need to train both elements to maximize your aerobic conditioning.

Picture aerobic conditioning as a sliding scale. On one end you have the shortest duration, highest intensity output, the ‘alactate’ burst of maximum power; on the other end you have the ‘all day’ maximum endurance effort. In between these two extremes you have the classic physiological energy systems:

Energy System:                               Duration:

1. Alactate                                                   <10 seconds          
2. Anaerobic Power                  1-4 minutes                
3. Vo2 Max                                  8-16 minutes                
4. Anaerobic Threshold           30-60 minutes                                  
5. Aerobic Threshold                2-4 hours                            
6. Endurance                              >4 hours

Training all six of these ‘zones’ of intensity is critical for all athletes. Balancing the amount, and at what point in the training year, each energy system is emphasized makes up an effective training program.

Aerobic Conditioning is Highly Trainable

Aerobic conditioning is highly trainable, although it can take many years to fully maximize in human physiology. Every human is born with an innate capacity to process oxygen. This is known as maximum oxygen uptake or, simply, Vo2 max. The more oxygen an athlete can supply to their working muscles the faster they can go. Vo2max is trainable to a certain extent, but everyone has their genetic ceiling of maximum uptake. One of the primary goals with aerobic conditioning is to maximize the sustainable percentage of Vo2max achievable in training and racing. This can be achieved by training any of the above mentioned energy systems; but is most effective by training all of the energy systems through an effective training program.

Longer & Slower

Long, slow distance training has been a staple of endurance sport training for years.Training longer durations at lower intensities has many identified benefits such as:

• increased mitochondria and capillary density to improve oxygen delivery
• maximizing the use of slow twitch muscle fibers
• improved fuel utilization and carbohydrate storage
• increase in the volume of blood your heart can move with each beat

For athletes that are coming to endurance sports from a ‘speed based’ background, and are relatively young, healthy, have the time, and have lofty goals of racing performance, high volume training can help them succeed. However, as valuable as the benefits of low-intensity training are, you must have the time to put into this method as it requires increasingly higher and higher volumes to create the stimulus needed for improved fitness.

Most amateur athletes with a job and family to balance with their training schedule usually can only find time for limited amounts of high volume training. Due to this, it leads us to consider how else can we improve our aerobic conditioning?

Shorter & Faster

Training the short, powerful, high intensity energy systems happens to also have many identified benefits. These benefits can often be achieved with much lower training volumes. Benefits of high intensity training include:

• increased oxygen uptake & utilization
• improved lactate tolerance
• maximizing the recruitment of both slow and fast twitch muscle fibers
• increased hormone production
• reduced insulin dependency
• improved movement efficiency

You can not ignore the benefits of high intensity training. Similarly, nor should you ignore the high intensity training in your training program. High intensity training definitely has its place in the sport performance training program; with the amount and timing of it being a key part of the metabolic puzzle.

Individuality in Aerobic Conditioning

Every individual has their own genetically given strengths. For example, some athletes are more powerful and faster over short distances; while others are built for the long haul and can maintain moderate outputs for extended periods of time. To maximize your own performance you must first identify your strengths and weaknesses. From there, you then create a training program that will improve your weaknesses while maximizing your strengths. In other words, by improving your short-term high intensity energy systems you can go faster for longer. Then by improving your long-term low intensity energy systems you can extend your speed over longer periods. These opposing ends of the physiological energy system scale should come together at some point inline with your targeted race-day intensity level you plan to predominantly utilize during your goal events.

Regardless of your strengths and weaknesses, your objective should be to create your own training program to give you the right amount of training stress to minimize fatigue and maximize performance.

The goal within your training program should be to apply just the right mix of both low & high intensity aerobic training to create the perfect amount of stimulus for your body to adapt to. Too much stimulus can lead to illness, fatigue or injury. Conversely, not enough stimulus and you fail to continue improving and don’t reach your fullest potential. In conclusion, mixing the right amount of training stress (balanced with “life stress”) into an individual’s training program is the secret to maximizing fitness and is unique to every athlete.