When diving into the science of operating efficiency, the idea of VO2max is sort of unavoidable.

Outlined merely, VO2max is the utmost price that your physique can extract oxygen from the air.

Whenever you run, that oxygen will get absorbed in your lungs into your bloodstream, will get pumped by the center, and travels to your muscle tissue, the place it’s put to make use of burning fats or carbs.

Everybody agrees about that half.

The controversy begins once you begin to ask the apparent subsequent questions:

1. How does VO2max contribute to efficiency
2. And what a part of the oxygen supply system—bloodstream, coronary heart, or muscle tissue—issues most in relation to figuring out your VO2max?

So, that’s what we’re going to look at in right this moment’s article by digging into the analysis.

VO2max measures metabolic energy, not operating pace

When runners speak about efficiency, we imply one thing very particular: pace!

Should you get an invite to look at a “high-performance 5k,” you’d justifiably expect to see some quick occasions.

However VO2max doesn’t measure pace—it simply estimates your physique’s metabolic energy output.

Extra particularly, it’s an estimate of your highest cardio energy: once you’re operating quick sufficient to hit VO2max, just about all the oxygen you’re consuming is getting used to burn carbs for vitality.

Having the ability to generate plenty of cardio vitality is nice, however it doesn’t assure that you simply’ll have the ability to run quick.

To go from cardio energy output to operating quick requires changing that metabolic energy into ahead movement—that’s the place operating economic system is available in.

Very like a automotive with a strong engine however flat tires, a excessive VO2max will not be very helpful if it’s paired with poor operating economic system.

For longer occasions, just like the 10k and half marathon, there’s an extra issue at play: your highest sustainable degree of oxygen consumption.

Usually, in the event you attempt to run at, say 90% or 95% of your VO2max, your oxygen consumption gained’t be secure—it’ll rapidly climb to 100% of your VO2max, and also you’ll quickly turn into too drained to proceed.

At a decrease worth, say 70 or 80% of your VO2max, you’ll have the ability to keep a secure price of oxygen consumption over time, and also you’ll final for much longer earlier than getting fatigued.

That worth—the best proportion of VO2max you possibly can keep at a steady-state—is your steady-state max.

Identical to runners can have completely different VO2max values, they will even have completely different values for this steady-state max—even when they’ve the identical VO2max!

To run quick, you want all three elements:

1. The power to supply a number of cardio vitality (VO2max)
2. Accomplish that in a sustainable means (steady-state max)
3. And effectively convert that vitality into ahead movement (operating economic system).

VO2max and efficiency in runners

Since VO2max is just one of three main elements influencing operating efficiency, it shouldn’t be shocking that VO2max by itself will not be a very good differentiator of operating means amongst runners who’re already fairly match.

One examine on practically 200 top-level Spanish runners discovered that VO2max by itself couldn’t establish the very best elite distance runners in comparison with their merely fairly good counterparts.

Moreover, Nike’s Breaking2 Undertaking, which did complete physiology testing on among the finest marathoners on this planet, discovered excessive, however not amazingly excessive VO2max values amongst these elite marathoners.

A lot of them clocked in at 65–70 mL/kg/min, though elite 5k runners can typically hit 80 mL/kg/min or greater.

In bigger and extra various samples, although, there’s no denying that there’s a hyperlink between VO2max and efficiency.

A 2021 examine of army recruits in Norway whose 3k race tempo ranged from practically 12:00/mi to six:00/mi discovered that VO2max alone defined two-thirds of the variation in efficiency throughout the recruits.

Clearly, a excessive VO2max is the worth of admission for high-level performances—however doesn’t assure quick occasions by itself.

Central or peripheral? Blood and coronary heart versus muscle tissue

The opposite large controversy with VO2max is what organic elements decide its worth.

In precept, any hyperlink within the oxygen supply chain (blood, coronary heart, or muscle tissue) may very well be the bottleneck.

One other mind-set about this query is whether or not you’re restricted by oxygen absorption by your blood, or oxygen utilization by your muscle tissue.

Most physiologists agree that the most important consider figuring out VO2max is solely what number of purple blood cells you may have.

Extra purple blood cells means extra hemoglobin, and extra hemoglobin means you possibly can carry extra oxygen in your blood.

As identified in a 2016 commentary article by physiologists Carsten Lundby, David Montero, and Michael Joyner, whole hemoglobin alone explains practically half of the variation in VO2max throughout athletes.

Should you incorporate cardiac output—the utmost quantity of blood your coronary heart can pump per minute—that fraction leaps to over 90%.

Issues solely get heated when contemplating whether or not blood quantity and cardiac output are the solely elements that matter.

Some physiologists imagine the above proof is convincing, whereas others argue {that a} sofa potato with an elite athlete’s coronary heart and bloodstream wouldn’t have the mandatory oxygen-extraction capabilities of their muscle tissue to make full use of the additional oxygen.

VO2max in follow: rising blood quantity and cardiac output

Whatever the controversy, one factor is obvious: in case your VO2max is limiting your efficiency, boosting your blood quantity and rising your cardiac output are probably the most promising methods.

As for learn how to go about boosting these two elements, the analysis is much less controversial: each blood quantity and cardiac output will be improved with interval exercises that hit no less than 90% VO2max.

In follow, which means coming inside about 8–10% of your most coronary heart price (or hitting >90% of coronary heart price reserve, if you need a extra exact metric).

For particular exercises, see the part under on completely different exercises you should use for varied race distances.

For optimum cardiac output advantages, these intervals must be supported by excessive general coaching quantity: padding out your weekly coaching with loads of straightforward to reasonable runs, to the extent that your coaching schedule permits.

Particular VO2 max Exercises you possibly can Implement

Now on to everybody’s favourite: the coaching particulars!

VO2 max for the 5k

Out of the commonest race distances, VO2 max is most essential within the 5k.

Whereas the primary portion of 5k coaching will give attention to constructing cardio endurance, consider this section as constructing the inspiration of a home.

The final 1/third of a 5k coaching plan, nevertheless, will emphasize VO2 max exercises – consider this because the roof.

A number of glorious examples of 5k particular VO2 max exercises are:

• 12 x 400 meters at 1 mile to 3k race tempo w/1:30-2:00 minutes relaxation

• 12 x 300 meters at 5k tempo w/ 30-40 seconds relaxation

• 5 x 3 minutes hill repeats with jog down restoration

Searching for extra info and exercises for coaching for a 5k?

Take a look at our 5k Particular Coaching put up. Or, how about our Base Coaching for 5k and 10k put up?

VO2 max for the 10k and half marathon

The particular calls for of the 10k and half marathon aren’t closely reliant on VO2 max, however it’s nonetheless an essential element to spherical out health.

Within the 10k and half marathon, it’s best to have a VO2 max exercise scheduled each 2-3 weeks to maintain the system in verify and assist different vitality techniques (cardio growth and threshold coaching).

My favourite exercises to mix into 10k coaching are:

• 16 x 400 meters at 5k – 10k tempo with each 4th 400 at 1 mile-3k tempo w/ 60 seconds between reps
• 4 miles steady tempo alternating 400m at 3k-5k tempo and 1200 meters at Marathon tempo
• 4 x 2 minutes Hills w/ jog down restoration, 1 mile on a flat floor at 10k tempo, 4 x 2 minute Hills w/ jog down restoration

We’ve got an awesome article on Particular Coaching for the 10k right here, and a 6 week 10k particular coaching plan for making use of the variation precept.

VO2 max for the Marathon

Sadly (or fortuitously, relying on how a lot you want lung-busting interval exercises), VO2max will not be an enormous element of marathon coaching.

Nevertheless, It’s nonetheless helpful and essential to incorporate some VO2 max exercises and pace work in your coaching plan each 3-4 weeks to assist your kind and effectivity.

My marathon go-to’s are as follows:

• 2 units of 10 x 400 meters at 5k tempo w/ 200 meters jog relaxation and 400 meters jog between every set

• 20 x 200 meters at Mile to 3km tempo w/ 200 meters jog restoration

• 6 x 3 minutes at 3k to 5k tempo w/ 3 minutes stroll or jog between

Recap

VO2max measures the best price at which your physique can extract oxygen from the air—and since oxygen is used to burn gasoline for vitality, it’s basically a measure of your cardio energy output.

Not surprisingly, VO2max is a big contributor to operating efficiency—however not the solely contributor.

To run quick, you want a excessive VO2max, the power to maintain a excessive proportion of your VO2max at a steady-state, and the power to effectively convert metabolic energy into ahead movement.

VO2max relies upon closely in your coronary heart and bloodstream: a lot of the variations in VO2max throughout completely different runners are attributable to the whole quantity of hemoglobin in your blood, and the utmost price your coronary heart can pump blood.

So-called “peripheral” elements, like how effectively your muscle tissue can extract and use oxygen, solely contribute somewhat to VO2max, if in any respect.

These peripheral elements do matter for efficiency, however most likely by way of their affect on whether or not you possibly can maintain a metabolic steady-state at a given price of oxygen consumption.

Understanding the origins of VO2max—and its limitations as a measure of efficiency—might help focus your coaching.

If VO2max is holding you again, one of the simplest ways to enhance it’s by specializing in exercises that concentrate on blood quantity and cardiac output: interval exercises with repeats that convey you inside about 8–10% of your most coronary heart price.