Are you looking to improve your aerobic fitness and stimulate training adaptation? Andrew Hamilton takes a look at why splitting your training into lots of low intensity work with a little high intensity could reap those extra rewards you're looking for…
How hard should you be training? Assuming you’ve got some kind of base fitness under your belt, you might be tempted to use a middle-of-the-road approach – in other words, train hard enough to push your body out of its comfort zone, but not train so hard as to exhaust yourself. While this may seem intuitively correct, a growing body of evidence suggests that there could be a better way – something called ‘polarised training’.
The polarised approach to training says that moderate to hard intensity training – or training near to your lactate threshold – is rather unproductive for making fitness gains. Instead, it proposes that endurance athletes would be better spending a large proportion of their time working at low intensity (in the ‘easy’ purely aerobic zone) and a small proportion at a very high intensity (near max power output), with very little time spent training at or near to lactate threshold.
The thinking is that polarised training provides an excellent ‘aerobic foundation’ yet allows for high-intensity work that really stimulates training adaptation without becoming too tired. On the flip side, the conventional middle-of-the-road approach means that you could spend much of your time training hard enough to tire you out and never leave you feeling really fresh, but never hard enough to provide the training stimulus your muscles need to make maximum fitness gains.
Follow the elites
The early evidence for the benefits of polarised training tended to be rather anecdotal; sports scientists noticed that many of the very best performing endurance athletes performed the bulk of their training at an easy intensity but combined with some extremely high-intensity work too. By contrast, lactate threshold training didn’t feature in most elites’ programmes.
In recent years however, studies have begun to reveal that the ubiquitous use of a polarised approach among elites is no coincidence, because it really does seem to offer performance benefits. For example, a 2012 study looked at cyclists who completed two blocks of six-week endurance training periods with similar total training volumes but with differing intensity distributions:
Polarised, averaging 6.4hrs/week, spending 80%, 0% and 20% of training time in low-, moderate- and high-intensity zones, respectively; and a much more middle-of-the-road block, averaging 7.5hrs/week spending 57%, 43% and 0% of training time in low-, moderate- and high-intensity zones, respectively.
Although both training periods produced fitness gains, the polarised training regime resulted in a 5% extra gain in peak power output, a 48% extra gain in high-intensity exercise capacity and a 7% extra gain in power output at lactate threshold. Meanwhile, two separate studies on the training intensity distributions used by speed skaters provided convincing evidence that the more polarised the approach the greater the performance.
These results also tie in neatly with those from a comprehensive and newly published study on triathletes, cyclists, runners and cross-country skiers, which compared four training approaches over a nine-week period (high-volume training, lactate threshold training, high-intensity interval training and polarised training) to see which produced the greatest gains in endurance performance.
The results showed that while the high-intensity intervals produced good gains, it was the polarised training that resulted in the greatest improvements. Interestingly, both the lactate threshold and high-volume approaches failed to produce any further improvement in endurance – that’s worth noting because it’s how many triathletes actually train.
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