There are a lot of sound reasons for molding traditional interval sessions into works in progress.
By now almost everyone has heard of progression runs, continuous faster-paced efforts that can take a number of forms — stand-along tempos, additions to the ends of medium-long or long runs, or whatever suits your goal event or training fancy.
And if you’ve never heard of interval workouts, you probably haven’t even reached this sentence. But have you ever done progression intervals? Probably not, but there are a lot of sound reasons for molding traditional interval sessions into works in progress.
Classic Intervals Reviewed
There are almost as many definitions of an interval workout as there are permutations of distances and rest durations. While “interval workout” probably remains the most popular, there’s also “VO2 max workout,” “HIIT” (for “high-intensity interval training,” really more of a Crossfitter’s term than a competitive runner’s label) or simply “speed work.”
These are runs from about 200m to about 1600m at around 3000m to 5000m race pace, or slightly faster separated by rest intervals of about 50 to 90 percent of the time it takes to run the reps, with proportionally more rest being set aside for shorter reps. The total volume of the workout ranges from about 3200m for newer competitors or athletes running the reps especially fast (e.g., milers) to about 8000m or sometimes more for seasoned marathon runners.
If there were such a thing as typical interval workouts for a runner with a recent 5K best close to 20:00 flat (6:24 pace per 1600m), they might be 12 x 400m in 90 or seconds (6:00 pace) with 1:15 rest jogs, or four times 1600m in 6:16 with 3:30 rest jogs.
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When, Why And How
In the two workouts above, for most runners it’s implied that consistency is the best way to go. In other words, the idea is to hover as close to the assigned pace as possible and then, if there’s significant fuel left in the tank, pick it up some in the last couple of reps. So our putative 20:00 runner having a good day might rack up times of 88, 90, 89, 90, 91, 91, 90, 91, 91, 90, 88, 85 and complete the first workout satisfactorily. On a different day, he or she might hit 1600m in 6:14, 6:17, 6:18, 6:14 — again, mission accomplished.
But is aiming for the target average every time out necessarily the ideal strategy, physiologically speaking? Most runners and coaches think that “consistency” by default translates to desirability. And when you’re doing a workout with the reps fixed at a single distance it’s much easier to keep track of one target than many. But it’s likely that when you think back on your best-ever track sessions, you may have run each rep progressively and significantly faster without intending to do so, and later attributed the result to having a great day or an insufficiently challenging schedule or both. Once I set out to run five times 1000m in 3:00 with 2:00 rest as I was preparing to take aim at 15:00 within a couple of weeks. I ran the first few in 3:02 and 3:01 and surprised myself over the next three, which went in 2:58, 2:56 and 2:53. I wound up ducking under my goal for the first time at age 34 after 20 years of racing.
But there are plenty of situations in which planning to run progression intervals rather than stumbling onto them as a natural consequence of other factors makes sense. One of those is when you only have a general idea of your fitness level, either because you’re coming back from an injury or haven’t raced or workout out formally in a while. Another is when you’re battling a mild illness — something like a cold, which isn’t severe enough to sideline you outright but demands a modicum of caution. A third is when there are non-fitness-related reasons you might find yourself dunked into oxygen debt well before you’ve finished the work you want to do, one of these being high altitude.
Brad Hudson, who leads a fluid group of elite distance runners in and around Boulder, Colo., holds most of the group’s track workouts at Fairview High School, which sits at about 5,400 feet above sea level. Virtually all of Hudson’s speed sessions are progressive in nature.
“I learned that from [British 10,000m Olympian] Karl Keska,” Hudson says. “We were both getting a little older, and he said that he’d started doing everything at ‘threshold feel’ to open up workouts, even 400s. And I agree with this — it’s just more important to get the work in than to hit exact paces, since you never know how you’re going to feel on any given day, particularly at altitude.”
Some examples what his faster runners do are 200s starting in 35-36 and working down to 32-33, and, for the national-class, four times 2K plus a 1K to finish starting at 72 seconds per 400 and dropping down to 68. Hudson believes that even if his runners were at sea level, conducting intervals in this manner would be wise because “it’s always good to ease gradually into any hard workout, no matter what kind of work you’re doing.”
So after you’ve established the number of reps you’ll be doing and the average pace you’ll shoot for, how far of a spread should you have between your beginning and ending reps? Looking at most available data, having fastest and slowest reps about 3 or 4 percent off your median time should be about right. So if you’re aiming for, say, 6 x 800m in 3:00, start at about 3:06 and wind up at about 2:54, chopping off 2 or 3 seconds with each rep. If you’re looking at 10 x 400 in 1:40, try working down from 1:44 to 1:36 and knocking off about a second each 400.
With enough of these workouts plugged into these programs, progress in your speed is all but assured.