You’re probably aware of the dreaded “gray area” of running training. Traditionally, the gray area is that spooky zone where you’re not going hard enough to elicit the desired adaptations, and not going easy enough to build aerobic endurance and recover. It’s where the crap hits the fan, the cats and dogs live together, the mass hysteria unfolds.
But a little bit of gray can go a long way, which would also be my catch phrase as an underdog contestant on Project Runway. Steady running, defined here as something easier than lactate threshold but not purely easy, can supercharge the aerobic system, optimizing power output while sparing glycogen stores, making every effort level more efficient. Let’s dig into some details.
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What is steady running?
Oh, sweet, sweet reader, if you think we’re going to have straightforward, non-controversial definitions, then I have an all-year ice-cream parlor to sell you in Minnesota. Steady running means different things in different training systems, with lots of debate around most of the topics in this article.
The general framework is that it’s easier than lactate threshold (LT), where lactate begins to accumulate in the bloodstream faster than can be cleared while staying at the same effort level. LT corresponds to rapidly increasing fatigue via chemical byproducts produced during glycolysis and glycogenolysis, where carbohydrates are turned into energy via the molecule ATP. It generally corresponds to one-hour effort, with individual variance.
Steady running uses primarily Type I slow-twitch muscle fibers, the type that power much of aerobic exercise (with the potential for recruitment of intermediate fibers as you fatigue).
On the lower end, steady running is usually harder than aerobic threshold, the point where the body transitions from primarily fat (lipid) metabolism to carbohydrate (glycogen) metabolism. Aerobic threshold is not an inflection point that can be labeled like you’re an eager pre-calc student. Instead, it’s more of an intensity range that many exercise scientists say corresponds to an effort that can be sustained for around a few hours, with lots of individual variance. In his book Marathon Training: A Scientific Approach, legendary coach Renato Canova refers to it as being around aerobic lipidic power, essentially meaning it’s both fast and sustainable. His training system for marathoners revolves around increasing that power so that output at lactate threshold and aerobic threshold get very close together. That’s why the top marathoners don’t look like they’re breathing all that hard at 5-minute miles—they have insane output around aerobic threshold.
Steady running can also include easier efforts than marathon effort, especially for faster runners. For Coach Greg McMillan, steady-state running generally means “easy-medium” effort.
That zone between LT and AeT has been called the gray area because it’s fast enough to cause some breakdown, but not fast enough to spur adaptations to top-end aerobic metrics directly. That last word, “directly,” is the key caveat there. And that underscores the primary benefits of sustained, steady running.
What are the benefits of steady running?
Different coaches and physiologists say steady running has slightly different purposes, though there is substantial overlap. The benefits can generally be grouped into three categories: aerobic/metabolic, musculoskeletal and neuromuscular.
Aerobic/metabolic benefits are the biggie, so they like it when you call them “big poppa.” Slow-burning lipids are a substantial source of fuel during steady running, which Canova says improves lipid consumption at faster paces over time. That’s a good thing, since you have a limited store of glycogen to fuel high-intensity exercise, but virtually unlimited fat stores. Get more efficient with lipid metabolism, and you’ll get immensely faster in long-distance races.
In addition, steady running uses primarily Type I slow-twitch muscle fibers, the type that power much of aerobic exercise (with the potential for recruitment of intermediate fibers as you fatigue). Steady running may also spur production of mitochondria and capillaries that transport fuel to working muscles, though the nature of the adaptations varies based on the intensity of the stimulus. Here’s where the word “directly” from the previous section comes into play—all of those adaptations are helpful in all aerobic exercise, even faster events like the 5K or 10K. So while you want a strong aerobic threshold with plenty of Type I fibers full of mitochondria and capillaries in the marathon most of all, that aerobic strength supports stronger track workouts for 5K runners or mountain workouts for 100-mile runners.
Steady runs carry higher injury risk than just going easy, they don’t spur the same level of top-end adaptations as faster intervals, and doing them too often causes overtraining.
For the musculoskeletal system, steady running provides substantial strain for longer periods, since a workout is not constrained by the same fatigue that hits above lactate threshold. That can lead to musculoskeletal adaptations that allow you to run stronger for longer. It’s one thing to have the aerobic system write the checks, it’s another to have the musculoskeletal system to cash them (as any trail runner that has been subject to “Jell-O legs” after a downhill can tell you).
Finally, steady running prepares athletes for the psychological grind of longer events. That’s one of Coach McMillan’s big reasons for steady runs—the neuromuscular system gets better at sustained efforts via sustained efforts.
What are the drawbacks of steady runs?
Steady-effort runs are awesome, but the conventional wisdom of the “gray area” is based in lots of physiological facts. Steady runs carry higher injury risk than just going easy, they don’t spur the same level of top-end adaptations as faster intervals, and doing them too often causes overtraining. On top of that, doing steady runs often when you are inefficient from lack of running economy development or tired from too much stress just reinforces bad habits.
A common occurrence is a runner doing steady runs most times out the door, running an “easy-medium” effort constantly. That usually results in injury, and, even if it doesn’t, the benefits are capped by a lack of running economy development (via faster intervals and strides) and aerobic development (via aerobic volume from easy running).
What does this mean for my training?
Steady running is another tool in your training toolbox, with its timing depending on the event and the athlete. Apply the principles of specificity—if you are doing a race that is similar effort like a half-marathon to 50K, you can do steady running in moderation right through to a few days before the race, if you are doing a much faster or slower race (like a mile or 100 mile), dial back as you get closer. For your training, the cool thing about steady runs is that they don’t have a big recovery cost and can be done most weeks without too much risk.
Steady runs can be structured workouts or unstructured progression efforts, incorporated within a long run or part of a mid-week run. Anecdotally, around one steady effort every week or two (I prefer them during long runs) seems to be plenty for athletes to get many of the benefits without risking injury or burnout.
For trail runners specifically, I like athletes to do steady running when they feel good, often during long runs after full development of base fitness, and often in an unstructured easy/moderate mentality where they let it flow based on the terrain. For advanced athletes, I’ll even say they can end some purely easy runs with a steady progression if they feel perfect and things are flowing (a method adopted from Canova that was common for many top runners in the 1970s).
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A template for an advanced athlete might be:
Tuesday: Easy run with strides
Wednesday: Workout with intervals or tempo focused on lactate threshold or faster, sometimes with steady running afterward (the post-workout steady running is something that Coach Joe Friel often has athletes practice)
Thursday: Easy run (option to end steady if they feel perfect)
Friday: Easy run
Saturday: Long run with sustained effort, often with substantial time at steady effort or marathon effort
Sunday: Easy run with strides
Some specific steady running workouts that I use for athletes are:
The Power Hour: One hour of steady running starting around marathon effort and ending harder if feeling good.
The Out-N-Back Attack: Run away from your starting point at a purely easy effort for 30 to 90 minutes, come back faster but not all-out.
Death by 1000 Cuts: On a long trail run, do every uphill or downhill at a steady effort, depending on goals.
Steady running is complicated at the margins, but the basic principles are simple. Don’t be afraid to run kinda fast sometimes. Most long races are kinda fast, and, in moderation, it makes you better at going really fast. Just don’t run kinda fast all the time.
David Roche partners with runners of all abilities through his coaching service, Some Work, All Play. With Megan Roche, M.D., he hosts the Some Work, All Play podcast on running (and other things), and they wrote a book called The Happy Runner.