Surges Are the Do-Everything Running Workout

Good running training is monotonous. When putting bricks in your training wall, most are going to be a similar size and shape.

“Just another brick,” you might think, looking at your training plan forlornly on a random Tuesday in January.

“La-dee-freaking-da.”

To stay healthy, you need to keep most runs alike. If every brick were unique, your training wall would crumble. Identical runs build on top of each other week after week, creating a strong foundation.

But as you’re building, you can throw in a few splashes of paint to make the process more interesting and your training wall stronger. Surges are a great way to do that.

What are surges?

Surges are mid-run accelerations, usually with full recovery (though not always), most often used during long runs. Tyler Pennel (winner of the 2014 U.S. Marathon championships) will sometimes add surges every 10 minutes in long runs. Kenyan training groups sometimes do a devilish version of surges, where a chase car beeps a horn to start and again to indicate a return to an easy pace.

Surges can vary in intensity, from a relatively easy burst like 1 minute at half-marathon effort every 10 minutes to harder fartlek workouts like 2 minutes at marathon pace every 5 minutes in the second half of a long run. The only rules: a surge breaks up a run in a semi-structured way for varying amounts of time, usually between 30 seconds and three minutes, interspersed with easy or moderate running in between.

Surges generally aren’t as intense as traditional interval workouts. Most intervals involve less rest, which may provide a better training stimulus for hard training sessions, but also risk injury and overtraining. In contrast, surges usually involve more recovery and a focus on sustainable, smooth speed. For example, a cruise interval workout might be 10 x 3 minutes at 10K effort/1 minute easy; a similar run with surges might be 1 minute at 10K effort every 5 minutes. That interval workout is tough and will get you closer to race ready in later phases of training; the surge workout is relaxed and will make that interval workout more efficient because the pace will feel easier.

Why do surges?

Depending on what type of workout you pair them with, surges offer a number of physiological benefits, which run the gamut from developing how fast you run at VO2 max to improving fat oxidation at faster paces, along with every other adaptation you’re looking for as a runner.

Any run you do provides a stimulus for aerobic development. From that base, adding fast surges with full recovery can improve running economy, reducing the amount of energy it takes to go a given pace. Slower, marathon-paced surges in a long run can maximize the time you spend at race efforts and improve fat oxidation without the recovery costs of a continuous tempo. Moderately fast surges do a bit of both—improving running economy and metabolic efficiency. Doing surges on trails can improve climbing, descending and technical ability, too. On top of all that, surges will generally speed up your overall pace without adding that much stress, enhancing aerobic adaptations.

Perhaps the most important benefit of surges is the psychological boost of breaking up an otherwise monotonous training run. On trails, surges give you boosts of adrenaline and race-effort joy. On roads, it gives you something to think about other than wishing you were on trails. And on a treadmill, it can help prevent you from deciding to quit the sport out of boredom.

You can probably imagine the dread of seeing “two hours easy” written on your training plan on a day when you just don’t want to slog through so much time on roads. Add some surges, though, and those two hours become much easier to digest.

Related: Workouts Should Be Smart, Not Hard

How to do surges

Surges come in more flavors than Baskin Robbins ice cream. But there are two general categories we use for our athletes.

1. Critical velocity surges:

Top coach Tom Schwartz defines critical velocity as 90 percent of VO₂ max, which equates to 30-35 minute race effort for most runners by his estimation. According to Schwartz, training at CV pace is the best way to improve how type IIa muscle fibers (a type of fast-twitch muscle that is more resistant to fatigue) process oxygen, leading to big improvements in running economy at both faster paces and slower paces. Surges at CV provides some of those benefits, without making harder workouts feel quite so hard, since you’re more comfortable at this sweet-spot CV pace.

Start by estimating the effort you could hold for 30-35 minutes (assuming you cannot do a lab test). For super-fast runners, that will be 10K effort; for others, it might be 5K effort or shorter. Some workout examples are:

Mid-week workout: 1 hour easy (at 15 minutes and every 5 minutes after, do 1.5 minutes at CV effort)

Weekend long run: 2 hours easy (at 30 minutes and every 6 minutes after, do 1 minute at CV effort)

The goal is not to hammer yourself—if you finish feeling like it wasn’t all that hard, you’re doing it right. You can do surges faster than CV, but keep them short (no more than a minute) to avoid making the run too hard, which can lead to overtraining or injury. For example, with treadmill workouts, we often like our athletes to do 30 seconds at 5K effort every 5 minutes.

2. Aerobic surges

Slower surges provide a lower-level aerobic stimulus, improving fat oxidation and making you more efficient at fast-but-not-too-fast efforts. Most of the time, those are the efforts you race at on trails, so slow surges are usually more race-specific for trail runners. In addition, they require less recovery and can be done a few times per week for an advanced athlete doing relatively unstructured training in the offseason.

One-hour-effort surges work lactate threshold; half-marathon- and marathon-effort surges get closer to aerobic threshold. All have their place in a training program, and all can be really fun on a monotonous workout day. Some workout examples are:

Mid-week workout: 1 hour easy (at 15 minutes and every 6 minutes after, do 3 minutes at marathon effort, 2.5 minutes at half-marathon effort or 2 minutes at lactate-threshold effort)

Weekend long run: 2 hours easy (at 15 minutes and every 10 minutes after, do 3 minutes at marathon effort, 2.5 minutes at half marathon effort or 1.5 minutes at lactate threshold effort)

There is no perfect surge workout, and the only limit to how you use surges in your training is your imagination. Start by adding aerobic surges, and work to faster ones if you like it.

Surges, like every workout, should be the frosting on top of your training cake, which consists mostly of easy running. But sometimes, a dollop of frosting makes everything way tastier.