Speed Work: Benefits and Pitfalls

If you want to run faster, consider the variations on how to train faster.


By Tom Denniss


If you want your running to get faster, there’s really only one option – run faster during training. There are many variations on training faster, but it all comes under the broad banner of speed work.

There are three general classes of speed work sessions – intervals, fartlek, and tempo runs, although some might consider hill work repeats as a case too (unless you run your hills very slowly).

Before I begin describing each type of speed work, let me say that the faster you run, the more damage will occur to muscle and tendon fibers, requiring longer periods of rest. If you run fast too often and don’t rest enough, YOU WILL GET INJURED. There is no magical way to prevent injuries other than adequate rest. But if you do allow enough rest between speed work sessions, the benefits will quickly accrue.

Interval training is perhaps the most common form of speed work. Run a particular distance quickly, then take an interval of rest before the next one. There are virtually an infinite number of variations on how you might conduct an interval session, but each fast portion is usually run on the same course.

Some runners like to do longer distances with the interval consisting of nothing more than standing still. Others like shorter distances with a short jog in between. Other like the jog to be longer. In fact, it’s not a bad idea to include various types of interval sessions in your training. A favorite of mine is 10 x 400 meters with a slow jog of 100 meters between each 400 meters. Many, however, prefer longer distances, such as 4 x 1 mile with a half mile jog as the interval. The combinations are limitless. The main thing is to ensure the faster running is of a high enough quality to stress the body.

Fartlek is a Swedish term meaning “speed play.” As the name suggests, a runner simply “plays with speed” by throwing in a faster bit of running when it suits them. It is not done by repeating the same stretch of road or track. Fartlek is traditionally conducted on trails, although that’s by no means necessary. For example, a 10 km road run might include a short sprint, followed by a quarter mile back at your normal pace, then a half mile at your 10 km pace, followed by a mile at normal pace, 200 meters at your flat out mile pace, then back to your normal pace again. There are no rules – just run whatever seems like fun. It’s probably the easiest form of speed work from a psychological point of view.

The third conventional type of speed work is the tempo run. Personally, I call these time trials. Pick a distance and run it as fast as you can (or close to it). You might say that tempo runs sound just like a race. However, there’s a difference. This is training, and you should use tempo runs to practice controlling and understanding the pace you can sustain over a particular distance.

It helps to ensure you don’t start races too fast and end up fading in great pain. And, at the same time, it will increase your general speed.

Overall, there are great benefits for a runner in participating in regular speed work sessions. You can’t help but get faster, UNLESS you get injured – the great pitfall of speed work. As mentioned previously, make sure you rest up well between speed work sessions. I would recommend no more than two sessions at most per week. And one session is fine. And you can still do normal runs on the non-speed work days, but keep them simple and non-intense. If unsure, err on the side of caution and take it easy. Remember, the stress of speed work will only lead to benefits if the body has time to repair itself between sessions.

Tom Denniss is an Australian athlete, scientist, and entrepreneur. He has a PhD in Mathematics and Oceanography, has invented a technology to convert the energy in ocean waves into electricity, founded a company to commercialise that technology, has played professional rugby league, and was a finalist in the 2014 Australian of the Year Award. In 2013 he set a new world record for the Fastest Circumnavigation of the Earth on Foot. Tom lives in Sydney, Australia. A former professional musician, he has played to audiences in eight countries. He has written various articles for newspapers, magazines, and journals, as well as a book about his run around the world, titled The World At My Feet. You can read more of Tom's work here.

Main Photo Credit & Second Photo Credit: Maridav/; Third Photo Credit: Denis Belitsky/

Apr 11, 2016

Very useful article ! 👍 Thank you Tom Denniss!