Can Starting Intervals Too Fast Give You a Better Workout? – Runner’s World
Can Starting Intervals Too Fast Give You a Better Workout? Runner’s World
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- According to published in the International Journal of Sports Physiology and Performance, starting a workout “too fast” might have more benefits than holding an even pace.
- Doing workouts in this way might help you run a faster 5K.
Imagine that you’re going to do a workout of one-kilometer repeats. A standard approach would be to aim for around 5K race pace and to run each repeat at an even pace. Closer to a goal race, you might want to work on your finishing kick, so you might run the first 800 meters of each repeat at 5K pace, and then try to speed up for the final 200 meters.
But what if you intentionally run the first part of each repeat faster than 5K pace, and then slow down toward the end? That can’t ever be a good idea, right?
As with so many things in running, the best answer is “it depends.” In this case, it depends on what you’re trying to accomplish in the workout. If you want to learn what 5K pace feels like so that it’s second-nature come race day, then yes, even pace is best. But if you want to spend as much time as possible working at your aerobic maximum, then you might want to consider purposefully starting each repeat “too fast,” new research suggests.
Off to a Quick Start
For in the International Journal of Sports Physiology and Performance, researchers at the Inland Norway University of Applied Sciences had 11 well-trained male Nordic skiers do interval workouts on four occasions. There were two workouts, each repeated on separate days, so that the researchers could gather more data.
One of the roller-ski workouts was straightforward: 5 x 5:00 bouts at 90 percent of maximum aerobic speed (MAS) with 3-minute recoveries between. (MAS is the fastest pace a well-trained endurance athlete can sustain for about six minutes.) In running terms, this workout is analogous to something like five one-kilometer repeats at 5K race pace. A chief goal of such a workout is to boost your VO2 max, which is the maximum rate at which you can deliver oxygen for use by your exercising muscles.
The second workout also included 5 x 5:00 hard repeats with three minutes easy between, but with this twist: The skiers did the first 90 seconds of each repeat at 100 percent of their MAS, then purposefully slowed to 85 percent of their MAS for the final three and a half minutes.
Among the data the researchers collected was the amount of time spent at 90 percent or more of VO2 max. In theory, the more time spent at that intensity, the more effective the workout was at increasing VO2 max. In the fast-start workout, the athletes spent almost 12 minutes at that intensity, compared to just more than 10:45 in the even-pace workout. The skiers also produced greater oxygen uptake, in both peak and average terms, during the fast-start workout.
Despite this evidence that they were working harder, the skiers rated their perceived exertion as slightly lower on the fast-start workout than during the traditional session.
Is This Workout for You?
Although this fast-start workout might sound novel, innovative runners and coaches use similar sessions, says Pete Magill, who holds three American age-group records and is the author of .
Magill calls them “blend intervals.” In these workouts, you run a short repeat, such as 400 meters, at an intense pace, such as mile race pace, take a 30- to 60-second recovery, then do a longer repeat, such as a mile, at 15K to half marathon pace, followed by a three-minute recovery to complete one set. A typical blend interval workout consists of three to five of these sets.
3 Blend Intervals to Build VO2 Max
Fast 5
- 10- to 20-minute warmup
- 5 x 5:00 interval, with the first 90 seconds at mile race pace and the last 3:30 at tempo pace (3:00 recovery jog between intervals)
- 10- to 20-minute cooldown
400 to Mile
- 10- to 20-minute warmup
- 400 meters at mile race pace (1:00 recovery jog)
- 1 mile at tempo pace (3:00 recovery jog)
- Repeat that set three more times
- 10- to 20-minute cooldown
Blended 800s
- 10- to 20-minute warmup
- 800 meters at 5K race pace (1:00 recovery jog)
- 800 meters at tempo pace (3:00 recovery jog)
- Repeat that set three more times
- 10- to 20-minute cooldown
The reasoning behind blend intervals and the new study’s fast-start workout is the same. Producing a strong VO2 max stimulus requires running at a pace that you can’t sustain for more than a handful of minutes. To be able to hit that pace on your next repeat, you need to take a decent recovery. So in a workout of five one-kilometer repeats at 5K race pace, you might take a 400-meter recovery jog between.
But because of that recovery jog, you then spend the first minute or two of your next repeat getting back up to 90 percent or more of your VO2 max. So while you’re no doubt working hard the whole time, if your goal is to max out your VO2 max, you might not be accomplishing as much as you thought. Remember, in the skiers’ traditional steady pace 5 x 5:00 workout, they spent less than 11 minutes at or above that 90-percent threshold.
Blend intervals and this study’s fast-start workout get around that problem by immediately placing your cardiovascular system under more severe stress. The quicker initial pace means you’ll have to slow, but even once you do, you’ll still be working at the desired intensity. published 40 years ago in the Canadian Journal of Applied Sport Sciences supports this approach.
It’s important to remember that, in the new study, the pace on the fast-start intervals was just as prescribed as during the even-pace workout. The idea wasn’t to go all-out for the first bit of each repeat and then hang on as best as possible while getting slower and slower. In running terms, the study’s workout could be done as five-minute intervals with the first 90 seconds at mile race pace and the final three and a half minutes at tempo pace. If you don’t have a good sense of what those paces feel like for you, a treadmill could be the perfect locale for this workout.
It’s also important to remember why you might do this or any other workout. Aiming to spend as much time as possible at 90 percent of VO2 max or higher makes the most sense early in a race season. As your most important races approach, workouts at goal race pace should take priority.
Contributing Writer Scott is a veteran running, fitness, and health journalist who has held senior editorial positions at Runner’s World and Running Times.