Doing speedwork on the trails can be challenging — one wrong step could have severe consequences, especially on more technical terrain. The variable nature of a trail, with rocks, roots, hills, valleys and even an occasional stream-crossing also makes it difficult to maintain a consistent pace during intervals. Still, if you’re preparing for a trail race, you’re going to want to practise going fast when you’re off-roading. A hill fartlek is a perfect way to incorporate speedwork into your trail run because you don’t have to worry so much about pace and it also gives you an opportunity to practise tackling the hills.
To do a hill fartlek, simply run at your regular pace, but every time you reach a hill, try to kick it up a notch. Once you crest the top of the hill, continue at that same effort level for 10 to 20 steps before relaxing back into your regular pace. Additionally, it’s not a bad idea to include the downhills as a part of your fartlek, since descending on a technical trail at speed is a skill that needs to be practised ahead of race day.
Of course, in order for this workout to be effective, you’re going to need to run on a trail that has more than one or two hills. Ideally, if you’re going for a 10K run, you want there to be at least 4 or 5 hills of varying steepness and length in order to get a good workout in. The great thing about this workout is that you don’t have to worry about pace, but instead base the intensity on perceived effort. You should be running up the hills at a speed that, when you reach the top, you’re able to continue running without stopping. The first few steps at the top of the hill will feel difficult, but if you’ve paced yourself correctly and you keep pushing, you should be able to recover fairly quickly without needing a break. This is great practice for race day, when you’re trying to avoid stopping and walking.
As always, before you head out into the trail, remember your safety tips: be sure to tell someone where you’re going, bring whatever fuel you will need (this is especially important for longer trail runs) and if you can, get yourself a good pair of trail shoes that will give you more support and traction to help you stay on your feet.