Do your hardest exercises at all times get off to a foul begin?
Once I first began working, the primary repeat of each exercise—and the primary half mile of each race—felt like a horrible shock to my system.
“There’s no method I can hold this up for 3 miles,” I’d assume to myself at first of a race. After a couple of minutes, I’d be feeling higher, however I at all times thought it was unusual that I felt so dangerous originally of exercises and races.
It wasn’t till a lot later that I discovered there’s a scientific rationalization for why I at all times felt sluggish originally of a tough effort—and even higher, there’s a scientific strategy to keep away from that sensation and enhance your efficiency.
What’s the trick? It’s referred to as a priming bout.
On this article, we’re going to dig deep into the science on…
- What’s a priming bout
- The analysis on how and why it improves efficiency
- The how and when to include it into your coaching and racing
What’s a priming bout, and why does it assist enhance efficiency?
The fundamentals of doing a priming bout are easy: after doing a typical warmup, you run for 4 to 6 minutes, at about 8k–10k effort, aiming to complete this priming bout round 10–20 minutes earlier than beginning your precise exercise or race.
To grasp why priming train works, although, we have to again up a bit and have a look at what occurs inside your physique once you begin working.
First, let’s take the instance of a straightforward run.
Within the first two to 3 minutes, your coronary heart charge and oxygen consumption rise sharply, then plateau.
Should you’re working at a good tempo (and on a day with cool temperatures), each of those metrics will stay unchanged, even ten or 20 minutes into your run.
The story is somewhat completely different at increased intensities.
While you begin a 5k, for instance, your coronary heart charge and oxygen consumption rise shortly for the primary two or three minutes of the race, then nearly plateau—however as an alternative of flattening out fully, each metrics proceed to float upward extra progressively.
By ten or quarter-hour into the race, they’ve drifted all the best way as much as their most values: your coronary heart charge is at your HRmax, and your oxygen consumption is at VO2max.
This sluggish rise in oxygen consumption (which drives the guts charge improve) known as the sluggish part of oxygen kinetics, and it’s the principle issue behind why priming bouts work [1].
Priming works as a result of it hurries up this sluggish part of oxygen consumption.
In different phrases, your oxygen consumption rises quicker, and sooner, throughout a tough effort should you’ve performed a priming bout.
As a result of your tissues are getting extra oxygen earlier into your exercise or race, you don’t have to dig into your anaerobic power reserves when you wait in your oxygen consumption to “catch up.”
Necessities for an efficient priming bout
Since priming depends on accelerating your physique’s sluggish part of oxygen kinetics, a priming bout wants to truly goal this mechanism to be efficient.
The science behind priming places just a few necessities on the construction of an efficient priming bout.
First, priming must be at a metabolically unsustainable depth: simple to average working received’t do the trick.
In observe, this implies you must run at about 8k to 10k effort in your priming bout.
Second, your priming bout must be lengthy sufficient to permit the sluggish part of oxygen kinetics to develop.
So, the bout ought to ideally final 4 to 6 minutes—any much less and your physique received’t have sufficient time to totally ramp up the sluggish part (although shorter priming bouts do nonetheless have some profit).
Third, you want sufficient time between your priming bout and the beginning of your exercise or race to recuperate.
Keep in mind, you’re burning via anaerobic power throughout the priming bout, so that you need to regenerate that power earlier than the principle occasion!
The optimum construction of a priming bout: 4-6 minutes, ending 10-20 minutes earlier than your race
An in depth examine from the College of Exeter examined a number of mixtures of priming bout depth and restoration in a gaggle of cyclists [2].
The outcomes confirmed simply what we’d count on: there’s a trade-off the place extra intense priming bouts speed up oxygen uptake extra sharply, however at the price of consuming into your anaerobic power reserves.
Essentially the most excessive protocol (6 minutes of exhausting train, a 3 minute relaxation, then a high-intensity experience to exhaustion) diminished endurance in comparison with no priming train in any respect.
Nevertheless, the simplest protocols—which concerned 9 or 20 minutes of relaxation between the priming bout and the experience to exhaustion—led to a 20% enchancment in time to exhaustion.
Although this examine and far of the opposite foundational analysis on priming used biking, the identical advantages have been present in working, even with shorter bouts of priming earlier than an 800m time trial [3].
When do you have to keep away from priming train?
The mechanisms behind priming additionally counsel there are some instances the place it doesn’t make sense to make use of—or a minimum of the place the advantages will likely be smaller.
Much less-fit runners could not profit as a lot from priming, for 2 causes.
First, they’re much less in a position to recuperate from the preliminary hit to their anaerobic power reserves. Second, due to their decrease VO2max, the magnitude of the profit from accelerating oxygen kinetics simply isn’t as giant.
Priming can also be much less helpful for longer races just like the half marathon or the marathon (and exercises at MP or HMP) [4].
In these occasions, oxygen consumption reaches a plateau finally, and the hit to your anaerobic power shops within the interim earlier than that plateau isn’t very massive, neither is it a significant component within the improvement of fatigue.
Lastly, should you’re injury-prone or making an attempt to maintain your mileage low, tacking on a full priming bout may not be a good suggestion due to the added mechanical stress in your physique.
Sooner working is extra damaging to bone and tendons per mile of working [5], so that you need to watch out with including further depth—and 4 to 6 minutes at a tough effort will be fairly a bit, particularly on high of an already-challenging exercise or race.
Recap
Priming is a superb addition to your warm-up earlier than a race or high-intensity exercise.
An efficient priming bout consists of 4–6 minutes of working at 8k to 10k effort. You need to do that priming bout after your normal warm-up run and strides, however end it 10–20 minutes earlier than the beginning of your race.
In exercises, this lengthy delay generally is a bit burdensome, so you could need to lower down on the size of the priming bout (and the restoration afterwards), even when this saps among the advantages. Even 200 meters of priming train exhibits some profit in runners [3].
Priming is much less helpful for longer races or exercises—something slower than threshold tempo or thereabouts tends to see little profit from priming.
So, save this warm-up approach for shorter races and extra intense exercises.

