VO2max: What Is It, Why Is It Important to Your Running Performance, and How Do You Improve It

Hello Runners,

There are three factors that are most important to your running performance and can affect whether you finish an event pumping your fists in celebration, or hanging your head in disappointment.

These factors are your running economy (basically how efficient you are when you run), your lactate threshold (maximum pace you can sustain for a prolonged period of time), and your VO2max or maximal oxygen consumption.

One of my workouts last week specifically focused on VO2max. For this particular workout, I performed a dynamic warmup and then ran at an easy pace for 20 minutes. Then the real fun began! I performed 40 second work bouts in a flat area (a track for example) at a hard pace. I focused on form during these work bouts to maximize my speed and effort. After each of these work bouts, I did a slow jog recovery interval for two minutes and then repeated for a total of six work bouts. I finished my run at an easy pace for approximately 10 minutes. Then I finished up by performing stability, mobility, and strengthening exercises and foam rolling. This was a challenging workout!

What Is VO2max?

VO2max is the maximal amount of oxygen our body can use to produce energy by aerobic energy systems when we are running at maximal effort, and is considered the “gold standard” for assessing aerobic fitness. VO2max is affected by our body’s ability to take oxygen into the body and deliver it to our running muscles, which incorporates our cardiovascular system, including the heart, blood, and blood vessels. Another important determinant of VO2max is the muscles’ ability to extract oxygen from the blood and use it to produce energy. This involves our “mighty” mitochondria in our muscle cells. The mitochondria are the powerhouses that will extract oxygen and use it along with carbohydrates, fats, and proteins in our body to the produce energy for us to run.

How Is VO2max Measured?

There are labs that will assess your VO2max by measuring the volume and composition of the gases you inhale and exhale while running. This test is usually performed on a treadmill in which the speed and/or incline is increased every 2-3 minutes. Basically, run until you feel you can run no more, or it is deemed that the test needs to be stopped for safety purposes. The test typically lasts ~12-15 minutes. As you might guess, it’s a hard test! In addition, you need to wear apparatus that will allow the volume and composition of gases to be measured. Here is an image of a typical VO2max testing setup:

vo2max testing

It is also possible to have VO2max measured outside while running on a track, although this requires sophisticated equipment.

VO2max can also be estimated based on time to run a mile. The advantage of this is that it doesn’t require sophisticated equipment and having to wear potentially uncomfortable apparatus. I offer this estimate as part of my running evaluation I do with runners. I can also offer this to runners who may not be able to do an in-person running evaluation with me.

It’s most helpful to repeat the measure of your VO2max after at least three months, to see if it has improved with your training.

What Factors Affect My VO2max?

There are several factors that affect VO2max including genetics, gender, age, fitness level, and training.

How Do I Improve My VO2max and Thus, My Running Performance?

There are several ways to improve VO2max depending on your fitness level. For beginner runners just running frequently and increasing the duration of your runs can significantly improve your VO2max, especially over three months.

For intermediate and advanced runners, it is more difficult to improve VO2max. However, hard work bouts in which you are running several minutes at ~95-100% of your current VO2max can help improve it. I recommend starting with hard work bouts for 30-40 seconds. Recover with a slow jog for 2-3 minutes between these bouts. Repeat for a total of 4-6 work bouts. Over the next 2-3 weeks, I recommend a progression in which you increase the time of your work bouts. This will depend on what’s appropriate for you. For runners I coach, we discuss how these work bouts went each week, as well as their fitness level to determine the appropriate progression. In addition, you should have been recently cleared by your physician to participate in vigorous physical activity. Also, you should have performed some previous speedwork, such as Fartlek runs, before engaging in VO2max work bouts.   

Please let me know if you have any questions, or if I can be of help in any way.

Also, if you feel anyone can benefit from this email, please share it.

Your friend and coach,


Another Reason Why You Won’t Achieve Your Running Goals for 2019 – Appropriate Training Plans for Women and Men

 “Instead of ignoring our differences, we need to accept and transcend them.”

― Sheryl Sandberg

Yesterday I had a brief conversation with a friend who is training for a half-ironman triathlon. Her workout for that day included intervals at a local track. This got me thinking about training plans and being purposeful with our workouts. Certainly intervals or bouts at higher intensity can be beneficial in our training plan. However, performing intervals just for the sake of performing intervals, or that we’ve heard it’s something we should do, may not be the best use of our limited time to train.

Thus, one important reason why runners don’t achieve their goals, and why you may not as well, is because they don’t follow an appropriate training plan, or don’t follow a plan at all. The training program should be appropriately designed for the specific needs and goals of the runner, while considering their age, running history, injury history, time for training, previous race results, and the topic I’m going to delve in a bit deeper in this post, which is physiology. The program should progressive build the runner to their goal, while including proper recovery, and an appropriate taper.

It seems many training programs, training groups, and running coaches don’t take important physiological differences into account, such as what is most appropriate for female and male runners. Due to the physiological differences between women and men, there is a strong tendency for women to use a higher percentage of fat as fuel, than men, when they run. Thus, the types of training and workouts that would be most beneficial to women, are not necessarily going to be the most beneficial for men. Since men tend to rely on carbohydrates for energy more than women, they may benefit more from higher intensity workouts to improve performance more than women. While women may benefit more from longer, aerobic-type workouts, which would include anaerobic or lactate threshold runs and intervals. Very few training groups will have runners perform intervals at the track in which they are running at their lactate threshold pace.

Women can benefit from higher intensity training, however the priority should be on the types of workouts that will most improve performance. Men also benefit from lactate threshold training, however this type of training is something I would incorporate later for them.

Of course, whether either of these types of intervals is appropriate for a runner will depend on their running history. In most cases with a beginner runner training for their first marathon, I may not use either type of interval.

Thus, for my friend who is early in her training for her half-ironman, I would recommend lactate threshold intervals, instead of hard maximal oxygen consumption (VO2max) intervals, which I would recommend if I were coaching a male triathlete. My friend would need to know what pace or effort would be most appropriate for her intervals. This could be based on testing, previous race performance, running by feel, or possibly a combination of these. In addition, she would need to know how many intervals to perform and the appropriate recovery. All important factors in getting the most benefit out of this type of workout.

For runners I coach, I provide them with appropriate paces, as well as appropriate number of intervals and recovery, whether they are performing lactate threshold, or VO2max intervals in the customized training plans that I develop for them. I will also offer this opportunity for those who use my training programs in my upcoming ebooks for training for half- or full-marathon.

Another important factor for women with regular menstrual cycles, is the effect that estrogen can have during training. Ideally, the progression of training workouts will match the changes in levels of estrogen to get the most benefit from workouts. This is something that I have worked with female runners on to maximize the benefits of their training, and would certainly offer to all female runners I coach.

Please let me know if you have any questions, or if I can be of help in any way.

I wish you the best with your training.

Your friend and coach,




  • Running for Women. Jason Karp and Carolyn Smith. Human Kinetics: Champaign, IL, 2012.