If you grew up in the 80′s and early 90′s, as I did, or maybe just watched a lot of Saturday morning cartoons with your children, you probably caught a few episodes of GI Joe. At the end of every episode, a member of the GI Joe team would illustrate an important life lesson and sign off saying: “Now you know, and knowing is half the battle.” (video)

This message is something I personally took to heart, and I think it’s very applicable to reaching your racing goals. Working hard and putting in the effort is a critical component to succeeding, but understanding the thought process and theory behind your training is also important. Knowing why you’re performing a certain workout or training a specific way can make reaching your goals easier, and provide that extra 10% needed to succeed on race day. With that in mind, I am going to explain the training concept of VO2max, why it’s useful, and how it applies to your training.

What is VO2max

Defined simply, VO2 max is the maximum amount of oxygen your body can utilize during exercise. It’s a combination of how much oxygen-rich blood your heart can pump and the muscles efficiency in extracting and utilizing the oxygen. Since oxygen is critical to running fast, your VO2 max is the single best measure of running fitness. Now, don’t confuse running fitness with running results. Having a high fitness level doesn’t always mean you will race well, there are many physiological and mental components to a great race, but having a high fitness level is extremely important.

More scientifically, as exercise intensity increases so does oxygen consumption. However, a point is reached where exercise intensity can continue to increase without the associated rise in oxygen consumption. This point at which oxygen consumption plateaus defines your VO2 max. To understand this in more practical terms, take a look at the diagram below:

Why Train at VO2max

Training at VO2max increases the amount of oxygen your body can use. Obviously, the more oxygen you can use, the faster you can run – that’s a simple one. In addition, VO2max running can increase the efficiency of your running and improve your form. Since VO2max workouts are much faster than normal training, they force you to run more efficiently and with better form.

Finally, training at VO2max also increases leg muscle strength and power, which improves economy (how much energy it takes to run at a certain speed). When muscles become stronger, fewer muscle fibers are needed to contract to hit a particular pace; thus the energy expenditure is lower, which can improve your fuel burning efficiency during a marathon or help propel you to faster times in the 5k.

How VO2max works for your event

While VO2max is a great measurement of running fitness for all distances, it’s more important the shorter your goal race is. All race distances require roughly the same physiological components (aerobic, anaerobic, VO2 max, fuel efficiency, running economy), but the optimal percentage of these demands changes based on the distance.

VO2 max for the 5k

Out of the most commonly run race distances, VO2 max is most important in the 5k. While the first portion of a 5k training schedule will focus on building aerobic endurance, think of this phase as building the foundation to a house, the last 1/3rd of a 5k training plan will emphasize VO2max workouts – think of it as the roof. Some good examples of 5k specific VO2 max workouts would be 12 x 400 meters at 1 mile to 3k race pace w/1:30-2:00 minutes rest.

VO2max for the 10k and half marathon

The specific demands of the 10k and half marathon aren’t heavily reliant on VO2max, but it is still an important component to round out the fitness. In the 10k and half marathon, you should have a VO2 max workout scheduled every 2-3 weeks to help keep the system in check and support your other energy systems (aerobic development and threshold training).

VO2 max for the Marathon

Unfortunately (or fortunately, depending on how much you like lung-busting interval workouts), VO2max is not a big component in marathon training. However, it is still useful and it is important to include some VO2 max workouts and speed work in your training plan once every 3-4 weeks to help tweak your form and efficiency.

I hope you’ve learned a little about VO2 max and how it is implemented into your training. If you have any questions about the physiological concepts or even how to work it into your training, just leave a comment.