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Run Free, Run Fast

That term ‘fartlek’ is omnipresent in training mags and websites, but how can it benefit the triathlete? Paul Larkins reveals all…

For us triathletes, used to measuring precisely the distance swum and miles ridden, to be told unstructured run-as-you-feel training can actually be a hugely beneficial part of your training programme is a little jarring to say the least. But when it comes to running fast, a fartlek session – basically mixing hard and easy efforts whenever you feel like it – really does work.

Swedish roots

Fartlek has its roots in Sweden (fartlek is Swedish for speed-play) where the famous milers of the 1940s, Haag and Anderson, both used the method to great effect, running tantalisingly close to four minutes for the mile. While fellow athletes of the period stuck religiously to the track and precise intervals, stopwatch in hand, these two used to head to the forest and… well, just run. Fast and slow, whenever they felt like it.

And that’s the key to all of this. Just as interval training – be it in the deadly accurate pool, on the track, or even on your bike using your equally precise computer – is a wonderful way of improving your performances, throwing away the stopwatch and any other measuring device will pay dividends as long as you mix and match the speeds you use. Run flat out, run slow, jog, run flat out, walk. Mix it up!

In a way (apart from the walking element), fartlek isn’t unlike a race in that, when you’re competing, you often jump out of your comfort zone to react to competitors passing you… or you passing them. Maybe you’ve caught a tough competitor and want to show them who’s boss. Don’t just ease away. Instead, surge hard and open up a gap. Yes, even-paced efforts are a great way of achieving great results, but being able to handle the competition around you is also vital. You need everything in your arsenal. As such, fartlek should be included in every triathlete’s training plan, whether you’re looking to win Hawaii or finish a local event.

My advice is: don’t get too rigid about a fartlek workout. Google the word and you’ll find limitless examples of how you can go about fartlek, most of which appear to complicate the issue enormously. But, in reality, a fartlek is simple – it can be done anywhere, on any surface, at any time, in any season, with no special kit required. As long as the fast bits are quicker than the slow sections, you’re doing it right!

Work it your way

If your race is short, say a sprint-distance triathlon, your training might include six efforts of a minute, two minutes, 30secs, 15secs and then two minutes. A longer event such as an Ironman could mean your fartlek involves longer efforts, say 15min hard, followed by a long easy period, perhaps another longer effort. ‘Perhaps’ is implied in all of this because fartlek is entirely up to you, and you can work it in any way you want. Surge hard when you see a bus on your run and stop when you see another one. Perhaps that’s 10secs on your route, perhaps half an hour.

My training group of five athletes use a slightly different method: each take a turn surging, not telling the others how far they’re going to make their effort. It’s tough… and it’s fun. There’s no watch to tell you how fast or slow each effort is, how far or how short. It doesn’t matter.

Should you do this? Just remember, one of the biggest ‘crimes’ in training is to keep everything the same pace. Do that and you’ll gradually become slower and slower. Include different pace work – such as fartlek – and the opposite will occur.

What’s more, fartlek works with every discipline. Swim hard when you pass Mr Jellyfish, ease off when you see him again. Accelerate on the bike when a red car passes you, keep the tempo high until you see a blue one. Do that 10 times and you have a great workout.

Science of fartlek


Profile image of Matt Baird Matt Baird Editor of Cycling Plus magazine


Matt is a regular contributor to 220 Triathlon, having joined the magazine in 2008. He’s raced everything from super-sprint to Ironman, duathlons and off-road triathlons, and can regularly be seen on the roads and trails around Bristol. Matt is the author of Triathlon! from Aurum Press and is now the editor of Cycling Plus magazine.