The necessity of speed work is debated amongst ultra runners. The two general sides are: Yes, speed work makes you fast and fit so you should do it vs. You can get fit running in the mountains and you don’t ever have to run fast in an ultra, so don’t bother.
Geof Roes and Anton K. are good examples of successful runners who don’t do speed work. But they run in the mountains…A LOT! A lot more than most people can handle physically. Plus, who has time for 3-5 hours of running nearly every day??
Gary Gellin, winner of Way Too Cool, calls himself a low mileage guy and also stated he does not do speed work. Instead, he got faster just by doing 2-3 hour runs every other day. But it took him several years of consistent running to get to the high level he is at now. So, yeah, you can get in great shape without speed work… if you have a lot of time and a lot of patience.
According to a 2011 study from the American College of Sports Medicine, just 2 weeks of high-intensity intervals improves your aerobic capacity as much as 6 to 8 weeks of endurance training. High intensity training is the most efficient way to improve VO2 max. A person’s VO2 max is tightly correlated with performance in endurance events. Certainly speed work is not the only way to improve VO2 max. But for people with a real life outside of running (or for people who just don’t want to spend that much time running every day), speed work is a valuable tool to improve fitness.
For ultra-runners the purpose of the speed work is not so much to train your legs to move fast, but to train your cardiovascular system to handle high physical stress and high metabolic demands. But besides improving fitness, speed work has other benefits:
- Improved range of motion. Ultra-runners usually develop a very efficient little stride. Unfortunately, this involves limited range of motion. Speed work forces you to open up your stride, lift your knees a little bit higher, pump your arms a little bit more, and stretch out those hamstrings. This is good for range of motion and improved mobility.
- Better leg turnover: No, most people won’t be hitting anything near their top speed in an ultra, but most ultras have at least some part where good leg turnover is an asset, particularly flat roads and smooth down hills. Better turnover in non-technical areas will lead to better finish times.
- Mental boost: When you watch your interval times fall, it is good feedback that your fitness is improving. Also, it is good knowledge for an ultra that you can recover after feeling totally spent. In interval workouts, you run hard, but then after just a few minutes, you are recovered enough to do it all again. The same principle applies to ultras – you can run up a hill, feel totally exhausted but then recover on the downhills, so you can do it all again on the next hill.
Speed work is a valuable tool for increasing cardiovascular fitness and V02 max, particularly for time crunched runners who don’t have all day to dedicate to training.