This is the second in our series of triathlon focussed blog posts. The first post can be found here.

There are 3 trainable overlapping energy systems that need to be trained effectively to run a good triathlon and training will need to be tailored to the specific distance triathlon someone is undertaking.

Energy systems

The challenge is to train each system optimally with the most effective time spent in each zone to maximize fitness outcomes.

The polarised approach to training in triathlon has many proponents including a large number of elite athletes. This approach consists of a high percentage of exercise time spent at low exercise intensity (∼75–80%) accompanied by a little time at moderate intensity (∼5–10%) with the remainder spent at high intensity (∼15–20%). It’s otherwise known as the 80/20 rule. The premise is that moderate to hard intensity training – or training near to your lactate threshold – can be unproductive for making fitness gains.

The thinking is that polarised training provides a very strong aerobic base yet allows for high-intensity work that really stimulates training adaptation without the athlete becoming too tired. This contrasts with the conventional middle-of-the-road approach that could have someone spending much of their time training hard enough to tire them out and never leaving them sufficiently fresh for hard zone 1 workouts that go on to provide the training stimulus muscles need to make maximum fitness gains.


Clive Lathey D.O MSc (Sports Medicine), Osteopath at the Putney Clinic, has a strong background in treating both professional and recreational triathletes and regularly speaks at conferences and seminars on triathlon training, injuries, injury prevention and rehabilitation. Here’s more information on the Putney Clinic’s sports injury clinic, or call the clinic on 020 8789 3881 to see how we may be able to help.