How Fast Should You Run in Training?

It's important to mix up your running pace and effort in order to keep improving

When I first started running regularly, just about every outing involved circling the park near my house at basically the same speed—go! I never even thought about varying my pace. If you’re a beginner, novice or intermediate runner and this resonates with you, you’re not alone. I’ve known many other runners to do the same thing. But it’s not a good training strategy, at all.

If you tend to go out and run as fast as you can, that’s a recipe for injury. If you never get out of first gear, your fitness will quickly plateau. To understand why it’s important to vary your pace and how to know how fast or slow to go, we turn to two run coaches, Tia Accetta, an RRCA-certified coach in Tucson, Ariz., and Eric Orton, the coach in the best-selling book, “Born to Run,” who hosts running camps in Jackson Hole, Wyoming.

“As with any skill, if you stay in your comfort zone, you won’t get better,” Accetta says. “If you’re training for a race you definitely want to vary the pace.”

Orton agrees, “Training methodology and fitness gains come from challenging the body, followed by some recovery. The challenge, whether it is more intensity, running more often and/or running long, causes the body to adapt to the stress/challenge, and the recovery allows for the body to rebuild and get strong, faster, fitter.”

Why should I vary my pace?

Accetta refers to slow-twitch, intermediate fast-twitch and fast-twitch muscle fibers. You need to address each in training, because “in a race, from 5K to marathon, you will recruit all three muscle types to varying degrees,” she says. “If you’re training for a marathon, you’ll want to spend more time running long, running at tempo pace and doing long intervals. If you’re training for a 5K, you’ll spend more time running at tempo pace and faster. However, if you want to be best prepared and most comfortable, you’ll want to carefully fit it ALL in.”

Accetta suggests most of your training be at a comfortable, conversational pace with higher intensity workouts every two or three runs. Those harder workouts could be a long run (90 minutes or more), hill repeats, tempo run, long intervals (2–6 minutes) or short intervals (20–90 seconds).

Orton explains that there are three key energy systems that you want to train: aerobic (long easy to moderate effort/distance), lactate (8-20 min moderately hard steady efforts) and anaerobic/VO2 (2-4 min hard/fast efforts). “The percentage of these might vary based on race distance and time of year, but you should for the most part always try to incorporate these into your running routine,” he says. “So, a very simple approach would be to include one run of each of these energy systems into your week.”

READ MORE: What You Need to Know to Run a Half Marathon

How do I dial in my speed?

Orton explains, based on the three energy systems, that your aerobic effort should be approximately 70–75 percent or a pace that feels easy for the length of your long run. Your lactate run should be 85–90 percent effort or approximately 60–80 seconds faster per mile than your easy effort. Your anaerobic/VO2 effort should feel like 95 percent or or 1:45–2:00 minutes faster than your easy pace. For example, if your easy pace is 9:00 min/mile, your lactate speed is 8:00–7:40 min/mile and anaerobic/VO2 effort is 7:00-7:15 min/mile pace.

“The key is, as you begin to include faster efforts into your training, they need to be done as intervals, so they are as fast as they need to be,” he says. “In other words, you can’t run fast enough for your anaerobic efforts if you are running longer than 4 minutes—it becomes another energy system and accomplishes something different.”

READ MORE: 5 Habits of Successful Runners

Accetta divides runs into five categories, explaining, “The difference between a ‘fast day’ and a ‘slow day’ depends on the goal of the run (which muscle fibers need flexing). I like to use a simple effort scale.”

Level 1 = Recovery run effort

You can maintain a conversation with ease because the running is almost effortless. A recovery run is a necessary follow up to a higher intensity run.

Level 2 = Marathon effort

This is “chit-chat” running. You can still talk, but the running takes a little more focus and energy. The majority of your weekly mileage will be at this effort level. Pace-wise, this is about 45–60 seconds faster than your recovery run pace.

Level 3 = Tempo effort

Running and talking get difficult to do at the same time. This is the effort that is just slightly out of your comfort zone but that you can maintain for up to an hour. Both slow-twitch and intermediate fast-twitch muscles get worked at this effort level.  Tempo effort is about 20–30 seconds slower than 5K pace.

Level 4 = Long interval effort

This is a moderately-hard effort that you can maintain for up to 6 minutes without slowing down. Long interval workouts of 2–6 minutes are good for practicing race efforts from 5K–15K. Intervals flex the slow-twitch and intermediate fast-twitch muscles and add strength and power to your running. Long interval effort is around 5–10 seconds faster than 5K pace.

Level 5 = Short interval effort

This is a hard effort reserved for shorter repeats between 20–90 seconds. You recruit intermediate and fast-twitch muscles. Short repeats are commonly sprinkled into training for the neuromuscular benefits; training your brain and muscles to fire and react more quickly. Short interval effort is about 30 seconds faster than 5K pace.

“Training becomes a more intuitive process when asked to explore the spectrum of your efforts, rather than hit specific paces,”Accetta says. “Gradually, as the goal race draws near, pace goals become more important.”

READ MORE: 8 Common Marathon Mistakes to Avoid

What if I’m not training for a race?

Both coaches agree on the need for varied speed, but what about when you aren’t registered for a race? “If you aren’t training for something, go fall in love with running,” Accetta says. “The more time spent running the better, so run whatever pace feels best, whatever makes you happiest.”

But you may have a goal, and this approach won’t help you get there. Orton explains, “I always tell runners, what you do needs to mirror your goals. So if you have no goals other than to get out for a run and just do what feels good that day, this is awesome. But if you want to improve performance or fitness or lose weight, you need to consistently challenge the body, followed by recovery. And the more you can train a variety of energy systems, and increase the training load, the better.”

READ MORE: 4 Keys to Not Going Out Too Fast in a Race

Nicki Miller
Nicki Miller is the former editor-in-chief of Competitor Running and managing editor of Women’s Running and is an RRCA certified coach. She loves encouraging runners, helping them avoid injury, covering sports nutrition and developing healthy recipes. Follow her at @nickiontherun