Aerobic Fitness
Aerobic fitness is defined as the ability to take in, transport and utilise oxygen. Compared to unfit individuals, aerobically trained adults live longer and enjoy a better quality of life. Although optimal health and longevity require a lifelong commitment to aerobic training, it is never too late to benefit from exercise. Blair et al., 1995 demonstrated in the Aerobic Centre Longitudinal Study that Coronary Heart Disease (CHD) mortality was reduced by more than 50% in unfit men who became fit and active. Aerobic fitness, or more correctly cardiorespiratory fitness, is also necessary for athletes and sports men/women if they want to reach peak physical performance.

Benefits of Aerobic Training
The benefits of aerobic training are well documented (ACSM, 2001).
Benefits include:

	Increase in stroke volume
	Decrease in resting heart rate
	Decrease in resting blood pressure (both systolic and diastolic)
	Increase in capillarisation
	Increase in the size and number of mitochondria
	Increase in number of red blood cells
	Increase in aerobic enzyme activity

The above central and peripheral adaptations cause an improvement in both cardiovascular health and physical performance, these include:

	Decreased incidence of Coronary Heart Disease
	Improved self-esteem
	Improved ability to recover during and after training
	Decreased percentage body fat
	Increased burning of fat at higher exercise intensities thus sparing glycogen
	Ability to work aerobically at higher exercise intensities

The extent to which the above adaptations increase aerobic fitness will depend on the manipulation of the following principles of training. Current guidelines state that aerobic fitness is increased by manipulating:

	Exercise Frequency
	Exercise Intensity
	Exercise Duration

Types of Aerobic Training
Central to any physical adaptation, is the understanding and application of training principles; in particular the principle of overload and specificity. These state that a minimum intensity of effort in necessary and the stimulus must be specific to the objectives if a fitness/performance adaptation is to occur. In other words, the oxygen system must be stressed in a manner that raises breathing and heart rate. It is noted, that any programme of physical activity will eventually plateau; therefore, consideration should be given to the long term plan if results are to be continued. If training consisted of doing the same activity over and over again, training would become very boring and the physiological adaptations will diminish. In essence, nothing in training happens by accident, but by design. In general, aerobic training can be grouped into three main headings.

Long Slow Duration/Distance (LSD) Training:
LSD training is what traditionally is thought of as aerobic training. It involves working for extended periods of time (usually 10+ minutes) at fairly low intensities (60-80% VO2 max). The intensity of LSD training can vary throughout the session and ideally sits the deconditioned or those individuals starting an exercise programme. Benefits of LSD training include all of the physiological adaptations discussed previously. For intermediate and advanced exercisers, LSD training has traditionally formed the majority of training for endurance-based sports such as the Marathon. However, whilst LSD is still beneficial, performed exclusively it will eventually stagnate fitness improvements. For example, a football player has to perform at various levels of intensity and move in many different directions for 90 minutes. Therefore, it doesn't make sense to continually perform LSD training in a straight line (which many football coaches still do!); as adaptations are specific to the type of stimulus applied. In this case, run slow to be slow!

Interval Training:
Interval training involves structured periods of work and recovery, and is an effective method to fully develop the aerobic energy system. Intervals can vary from a few seconds to several minutes. Exercising at higher intensities (which is the case in most sports and activities) can only be maintained for a couple of minutes, due to oxygen demand being outstripped by oxygen supply. Therefore, to maintain a higher intensity of exercise, the lactic acid energy system chips in to provide the remainder of the energy needed.

One befit of interval training, which is of importance to many athletes and sportsman/women, is that it develops the individual's ability to tolerate high levels of lactic acid, and the rate at which it is removed from the muscles. The following guidelines will be considered when prescribing an interval programme:

	Interval Intensity
	Interval Duration
	Interval Recovery Period
	Number of intervals including recovery periods

Consider the following examples; an intermediate exercises is prescribed the following aerobic interval training session: 3 min work interval followed by 3 min recovery, performed 2-5 times. For an advanced exerciser it might look like this: 3 min work interval followed by 90 second rest interval and performed 4-6 times. These examples clearly demonstrate the difference in fitness levels needed to perform, especially in the ability to recover after each work interval.

Fartlek Training:
Fartlek is a Swedish term meaning 'speed play' and involves the random interplay of different speeds. Fartlek training can be considered an unstructured form of interval training where the total amount of work is performed (around 30-40 minutes), but instead of working at one intensity (as LSD training) the intensity is changed sporadically. This is an excellent way of performing interval training and can be a lot of fun, particularly if performed outside, for example, in a park!

Prescribing Aerobic Exercise
The following table shows current guidelines for Aerobic training for both maintaining health and improving Aerobic Fitness:

	Maintaining Health:	Improving Fitness:
Frequency	5 x per week	3 x per week
Intensity	Moderate	Vigorous
Time	> 30 minutes	> 20 minutes
Type	Rhythmical exercise using large muscle groups

The above table provide a useful starting point for any individual wishing to embark on Aerobic Exercise. However, it does throw up some questions! Firstly, and most importantly, what is meant by the terms moderate and vigorous? Aerobic training has been demonstrated to be beneficial when performed at an intensity of 60-90% of Maximum Heart Rate (MHR). It can be agreed; this is a large range and begs the question - is it better to work at the lower end of the HR range or the higher HR end? Furthermore, using percentage of the MHR to prescribe intensity is fundamentally flawed due to individual differences in MHR.

Moderate intensity exercise is defined as an intensity which causes a person to become slightly out of breath without undue fatigue. For the majority of unfit individuals this would represent an activity such as a brisk walk or gentle cycle, and is associated with the lower end 60-90% MHR; although, it is dependant on individual fitness levels. Perhaps a more useful way of monitoring intensity during aerobic exercise, if the individual isn't wearing a Heart Rate Monitor, is to use Borg's Rating of Perceived Exertion (RPE). Using the RPE scale, moderate intensity exercise is perceived as 'light' or RPE of 11. It is interesting to note, that around 65% of men and 75% of women do not do enough activity to meet these guidelines of 30 minutes of moderate intensity activity, 5 times per week! (ACSM, 1998)

Vigorous exercise causes individuals to become out of breath, and start to sweat. For these reason, vigorous exercise would correlate to the top end of 60-90% MHR. However, it again, is dependent on individual fitness levels. As with moderate intensity exercise, I would be able to use the RPE scale to monitor vigorous intensity. Vigorous intensity is classed as 'somewhat hard' to 'hard' or RPE of 13-14. Vigorous activity causes greater improvements in fitness levels, although, it is not necessary to confer health benefits (ACSM, 2001)

Training beginners:
Beginners should perform moderate intensity activities that do not cause undue fatigue, discomfort or muscle soreness. Beginners will initially train 3-4 times per week building towards the guidelines of 5 times per week. The duration of the session should aim towards 30 minutes of continuous exercise. Individuals who are particularly unfit might not be able to continuously work for 30 minutes, in which case they will be encouraged to work for as long as they can, working towards 30 minutes using an interval type approach. It is important to note, that beginners will demonstrate improvements in fitness quite quickly and my plateau in as little as three weeks. It is, therefore, important that we increase the exercise stimulus accordingly.

Training intermediate and advanced exercisers:
Once you can complete 30 minutes of moderate intensity activity 5 times per week it is time to progress your training by manipulating the training principles. The most obvious change would be to increase the intensity of exercise within each session. For example, if the person had been working for 30 minutes at 60% MHR, it would be sensible to increase the intensity to 70% MHR. In addition, we could also increase exercise building towards an hour. It is crucial that we do not attempt to progress the individual to fast. This approach will only de-motivate the individual and possibly lead to an overuse injury because of the increase in training volume.

As the individual's fitness levels improve we can continue to increase the intensity up to 'vigorous' in parallel with the manipulation of exercise duration. An excellent way of introducing a vigorous intensity is the application of interval training. The individual will be encouraged to work at a moderate intensity with periods of high intensity. The long term goal is to work towards being able to complete a whole session at a vigorous intensity. Finally, we'll be mixing LSD, Interval and Fartlek training due to the variety of training stimuli this would present and the great benefits.

Ironman
Base training by:
Ironman Triathlon, Professional Olympic Triathlon Training Coach Mark Allen

There are many factors that will influence your racing. Nutrition, tapering, speed work, rest, and mindset are some of them. But the biggest physical factor is the base you build in the beginning of the season. A good base period when you develop your body's ability to burn stored fat for fuel is what determines the size of the internal engine that the other things have to work with.

A well-designed base period enables you to take good nutrition, speed work, rest, and positive thoughts and transform them into your best race possible. The choice is yours. You can either try to race with an engine the size of a lawnmower or you can build your engine up with a good base so that you are racing with a huge-turbo charged jet engine.

The catch is that most people do not have the patience to build a base correctly. The reason is that for the first 12 weeks or so of your season, you will have to strap on a heart rate monitor and put your ego aside. What the heart rate monitor will signal to you is when you are working out at heart rates that are aerobic (fat burning).

These are in the lower training zones well below your maximum heart rate. The higher heart rates are anaerobic (carbohydrate burning) and shouldn't come until your base has been built. The reason is that the improvement you can get in performance from developing your aerobic fat burning system is huge compared to the improvement in performance you can get from doing the high-end anaerobic carbohydrate burning workouts. And our bodies cannot develop both systems very well at the same time. Which means that to build a base properly, an athlete has to have the patience to work the aerobic system exclusively for a huge block of time.

But before we go any further, let me give you a formula that you may have seen before. It is one that will help you determine what the upper limit of your aerobic training zone is.

Here it is:
1. Take 180
2. Subtract your age
3. Take this number and correct it by the following:

	If you do not workout, subtract another 5 beats.
	If you workout only 1-2 days a week, only subtract 2 or 3 beats.
	If you workout 3-4 times a week keep the number where it is.
	If you workout 5-6 times a week keep the number where it is.
	If you workout 7 or more times a week and have done so for over a year, add 5 beats to the number.
	If you are over about 55 years old or younger than about 25 years old, add another 5 beats to whatever number you now have.
	If you are about 60 years old or older OR if you are about 20 years old or younger, add an additional 5 beats to the corrected number you now have.

The number you now have is the upper heart rate limit that you can work out at and still develop your aerobic system. This is the heart rate that will build the size of your engine. Now back to the catch!

In the beginning of the season just about everyone will have lost a lot of their aerobic base, especially if in the season before you did little aerobic and mostly anaerobic training. What this means in your workouts is that you have very little ability to burn fat as a source of fuel for exercise and your heart rate will jump up very high at a relatively slow pace in an attempt to kick your metabolism into carbohydrate burning. And to keep from going over your aerobic limit you will have to slow your pace down, often significantly.

This is where most athletes do not have the patience to stick with the aerobic training. You may have to slow down several minutes per mile from your normal everyday training pace just to keep your heart rate from going above the aerobic maximum. Your perceived effort can be very, very low while you are developing your aerobic engine.

And this is when one's patience is tested. Workouts will feel the opposite of the mentality that says training should be painful and muscles need to burn to get benefit. This may be true later during the speed phase of the season. But right now, this is absolutely not correct. You will be getting huge benefit that will show up months down the road.

When I started back each season, I had always lost a lot of my aerobic capacity. This meant that I had a small internal engine. During those first few months of training, I would literally have to walk up even the easy hills on my runs to keep my heart rate from going too high and kicking my body into carbohydrate metabolism.

But slowly, over those next 12 weeks, my body would develop the enzymes necessary to break down stored fat for energy and my pace would speed up. And by the time it came to do my interval training, I was able to run close to a 5:30 mile at my aerobic maximum heart rate of 150!

Here is your base building training prescription:

	For the next 10-12 weeks do exclusively aerobic workouts.
	Give yourself 5-15 minutes to warm up, slowly elevating your heart rate as you go. Then during the bulk of the workout, try to keep your heart rate in a range that is at least 80% of your maximum aerobic heart rate but not higher than that number. So for example, if your maximum aerobic heart rate is 150, try to work out the main part of your training session in a range that is from 120-150.
	Do every single workout in this range: Endurance days, moderate length days, hilly days, all of them the same. No cheating. No going over just a little in each workout.
	Walk the hills. Put the chain in a smaller gear. Do whatever it takes to keep from going over your maximum number. Once your base has been built you will have plenty of opportunity to work in the more "painful" heart rates.

You now have the secret to building a good base, and more importantly training correctly in the early season to have your best race when it counts!
So, who am I again?