NEW INTERVAL TRAINING
"If you want to understand today, you have to search yesterday." Pearl Buck
History of New Interval Training
Read the history below or click on any topic above to go directly to that section.
In 1994 I was in Seattle, Washington researching the metabolic contributions to performance and spent some time, as I morphed into ‘anorak mode’ every year at around that time, in the basement Medical Library of the University of Washington looking for greater personal understanding of the energy systems. This was before the days of computerised searches and ‘cut and paste’ capabilities. Those familiar with any review of research literature from the past know well the painstaking progress that needed to be made. As I methodically worked through the massive bound volumes of research citations, pursuing original research and links that looked promising, a phrase suddenly caught my eye. I had stumbled upon something called the ‘Lactate Shuttle’.
This ‘Lactate Shuttle’ hypothesis had been proposed by Dr George Brooks of the University of California in Berkeley, following his 1986 research which had been specifically aimed at determining the metabolic role and fate of lactate produced in the human body. This had been made possible by injecting willing research subjects with lactate that had been ‘tagged’ isotopically. Study of the dilution of the ‘tagged’ lactate had clearly revealed that lactate production occurs within skeletal muscle during rest as well as during exercise (Brooks GA 1986).
The 1986 paper and his subsequent research work showed that lactate is not a metabolic dead-end and its formation does not mean that all the potential energy stored within the carbohydrate has been wasted. I read fascinated as he explained how lactate was a powerful fuel for the production of ATP and the Lactate Shuttle explained the movement and usage of lactate around the body.
I read, gripped and focused, as Brooks explained how lactate is being produced in the human body all the time, not just “when the body runs out of oxygen” as we had always been taught. As I sat there reading Brooks’ material I was thinking at the same time of the types of track work and Fartlek training that I favoured. Things were falling into place. When you increased the intensity in the faster sections lactate production was increased and when you reduced intensity the lactate was utilised as the preferred fuel for aerobic ATP production and ‘cleared’. This was my first sense of, “Eureka” and it was truly an 'Aha!' moment relating to Brooks’ work.
From this 'Aha' moment I proposed the concept of ‘Lactate Dynamics Training’ based on the successes that I and others had experienced using variable pace work. I defined Lactate Dynamics Training as any form of training where lactate production is deliberately increased by the intensity of exercise and then alternated with periods of slightly less intense activity. In this way the muscle cells ‘learn’ how to both use and clear the produced lactate during the less intense recoveries.
It took me a few months of coaching back in the UK and of integrating the Lactate Dynamics Training concepts into the new IAAF coach education manual, Intermediate Coaching Theory, I was writing at that time before I had my second 'Aha' moment. And, in fact, it was probably less of a singular 'Aha' moment and more of a dawning realisation that with this type of training, the faster repetitions or sections create more lactate and in the easier recovery sections the body learns to use and clear the lactate more efficiently. The training effect therefore was the body’s adaptation to use and clear lactate and this was taking place in the easier, recovery sections. And, the faster the ‘easier’ recoveries could naturally be the greater the training effect would result. This thinking supported the practice of active, roll-on recoveries as being the best option
"So," I thought, "the training effect actually takes place in the recovery interval between the faster repetition sections." Casting my mind back to Gerschler’s Interval Training, I realised that this was ‘Interval Training’ as well. But in this Lactate Dynamics Training driven ‘Interval Training’ there was a fundamentally different process that was taking place in the recovery intervals compared to Gerschler’s recovery intervals. From this dawning realisation, I decided in early 1995 that this training must correctly be called the ‘New Interval Training’ for two reasons. Firstly, to clearly identify when the training effect was taking place and secondly, to clearly distinguish it from Gerschler’s original Interval Training.
When I had returned to the UK in 1994 to speak with eminent sports physiologists about what I had read in Seattle and what I had inferred, they just shook their heads. “Yes, we know of Brooks’ work but nobody takes it seriously.” Now they have changed their view. In the past decade the work of George Brooks has become accepted as the cutting-edge of research and, still, he leads the field but now surrounded and supported around the world by the work of a phalanx of independent researchers.