Love it or hate it, interval training is here to stay and you should be doing it. I’ve never been a big proponent of doing speed work as an ultrarunner. Ultrarunners don’t run “fast” so why should we train fast? it increases your risk of injury and I’d rather focus on things that reduce my risk of injury. So the big questions why would we do interval training as ultrarunners and how do we reduce our risk of injury.
First, let’s address the injury issue. There are things you can do to reduce the possibility of sustaining an injury during interval training. Do a warm up! Run at a slow pace for 10 minutes. Don’t use static stretching before you run. Do use dynamic stretches such as high knees, butt kicks and toy soldiers before you start, but not a ton 20 meters of each is enough. Do three box jumps. Take advantage of your recovery time. If you have a history of hamstring pulls, knee pain, or other lower body injuries do your intervals on hills rather than on flat ground. If your injury prone or coming back from an injury do your intervals on a bike or other stationary exercise equipment. You can even do them in the swimming pool as pool running.
The Why. You should do interval training because at some point you’re going to hit a plateau in your training if you are always running near the same pace. Most of the gains you’ll make will happen early. Later gains will come but much more slowly and then it will feel like you’re not making any progress.
The reason is you’re not challenging your body and it has adapted as far as it’s going to without another stressor. As runners we want to be able to improve the cardiovascular and respiratory systems along with muscle strength. That’s how we get better. Interval training trains a different part of those same systems. When you make an improvement in one aspect, it increases your ability to make gains in the one that has plateaued.
Interval training is the best way to increase your Vo2 Max and your Lactate threshold, which are two aspects of that same system we use as ultrarunners. Here are a couple workouts you can use to increase both. It’s best to use these your early training blocks and then as you get closer to race day drop these in favor of more race specific training such as climbing/descending, heat training and the like.
Vo2 max: All out for three minutes, recover for three minutes. Repeat 5-8 times. Do this two days a week for four to six weeks.
Lactate threshold: Run as fast as you can sustain for 40 to 60 minutes (like a tempo run). Do this two days a week for four to six weeks. You can break these up into ten minute blocks (ten on ten off) but keep the total hard time as 40-60 minutes.