70.3 Training Principals, Part 2

By the Silver Fox*


Training intensity

The more controversial of all training principles is training intensity. Most triathletes will agree with the recommendations for frequency and duration, but might differ of opinion in relation to the use of different intensities.

In New Zealand most of our triathletes use a simple 5 point training intensity scale which is based on distinct physiological responses at each level(Table 1).

The first 3 simply called easy, steady and moderate are all in the aerobic zones. Oxygen fuels the burning of carbohydrates and fats. In these 3 aerobic zones the overall oxygen supply meets the total oxygen demand resulting in very efficient energy production. The body adapts in a healthy way and the immune system is strengthened. In view of the health benefits which are connected with exercising in these zones they are also called the “anabolic (build up) zones”.

This is in contrary to the hard and very hard zones where the oxygen demand exceeds the amount of oxygen the body can provide. This results in fuels being burned less efficiently and with the formation of by-products, which include lactate and protons. The lactate is subsequently used as a fuel by the heart muscle and other muscles which are still in an aerobic state but the protons add to the stress on the body in addition to other effects created by oxygen deficiency. The immune and hormonal systems are initially suppressed and it takes a while for the body to recover. These zones are therefore also called “the catabolic (break down) zones”. You break down before you adapt.

During the more aerobic anabolic intensities the body adapts almost straight away.. A lot of work can be done in the aerobic zones once you acquire a good base fitness.

It is the effects of the anaerobic zones which are more directly responsible for symptoms of overtraining.

The aerobic zones are the dominant zones when training for 70.3 events


Table 1: The Training Intensity Scale


Subjective perception

Heart rate is beats/minute(bpm).

Training effect

Training application


Very comfortable, breathing and heart rate only slightly elevated.

Subtract 50 bpm or more from your maximum heart rate.

Increase circulation and temperature of working muscles

Warm up, cool down, technique


Comfortable, can be sustained for long time conversation pace

Subtract 30-50bpm from your maximum heart rate.

Improve aerobic (oxygen dependant) metabolic efficiency

Major component of long distance training


Becoming a little harder, difficult to have a conversation, can be maintained for longer by well trained athletes

Subtract 20-40bpm from your maximum heart rate.

Improve transition from aerobic to anaerobic metabolism

Component of progressive training, longer time trials (10-30 min and repetitions (4-10 min)


(Lactate threshold pace)

No conversation possible, somewhat painful, difficult to maintain for longer periods

Subtract 10-30bpm from your maximum heart rate.

Improve anaerobic (oxygen independent) metabolic efficiency)

Shorter time trials (6-20 min) and repetitions (3-6 min)

Very hard

(VO2max pace)

This is well beyond race pace, only relevant for pro athletes who at times have to be able to use this intensity in races for short periods

Subtract 10bpm or less from your maximum heart rate.

Improved lactate tolerance and improved VO2max

Very short repetitions (1-3 min)





Table 2 below summarises the training principles for the 70.3 ironman. These principles apply especially in the 8 weeks prior to the event providing that you have done base training in the three disciplines prior to this time.


Table 2: Summary of training principles for 70.3 events.

70.3 training principles

Frequency (sessions per discipline per week)

Duration (minutes)

Training intensity

Race intensity

Group ii)

Recreational Triathlete


Swim 30-60

Bike 90-240

Run 30-120

Easy and steady



Group iii)

Age group Triathlete 70.3 in preparation for ironman


Swim 45-90

Bike 90-300

Run 30-150

Easy, steady, some moderate

Easy-steady- some moderate

Group iv)

Age group Triathlete 70.3


Swim 45-90

Bike 90-240

Run 30-120

Easy, steady, moderate and some hard


Group 5

Professional Triathlete 70.3 and ironman


Swim 60-120

Bike 90-360

Run 30-150

Easy, steady, moderate and some hard and v hard



In the next article it will become clear how these principles can be applied to individual training programmes.





* Silver fox comes from the name “the old fox” which is how the author John Hellemans was referred to when welcomed across the finish line by the race announcer when he won his first official New Zealand Triathlon title. Much to his dismay the athletes he coached soon turned the nickname into the grey fox. In more recent years they have respectfully changed it to the silver fox.



Photo by this pages editor 'TriathlonShots'.







Copyright © 2006 www.triathlonshots.com - All Rights Reserved.