The (Maybe Not So) Almighty VO2max: Part 2

Note: See Part 1 if you need some background.

Can my VO2max change?

Yes. It can go up (yay!) and down (boo!). Increases depend on your initial fitness and what type of training program you follow. Studies have shown in healthy people that VO2max can go up significantly in as little as 2-3 weeks, although most studies demonstrate increases in 6-9 weeks. The increase ranges between 5-20% depending on initial fitness and the type of training. But just as it goes up, it also goes down. If you don’t use it, you lose it within a few weeks. This means no activity or detraining.

For more competitive endurance athletes, studies following them over a season have shown no significant changes (up or down) in VO2max. Remember though that even when not competing, these types of athletes maintain a structured endurance training plan most weeks out of the year. Also, remember that these studies are looking for changes in groups to determine significant changes. As an individual you may see changes that are meaningful to you. But competitive athletes will see decreases with no training within 8 weeks. Yet Madsen et al. showed over 4-weeks that it takes just one 35-min high intensity training session per week (and that is it) to maintain VO2max in competitive athletes.


VO2max declines with age. Yep. Bummer. This is primarily driven by the fact that your maximum heart rate goes down with age. (Note: staying fit does not prevent your maximum heart rate from going down, it can slow the rate it goes down.) Just because your maximum heart rate and VO2max go down does not necessarily mean you will be slower. Why? … If you read VO2max Part 1, there are two other important factors associated with endurance performance: lactate threshold, and efficiency or economy.

Other Important Factors

Let’s say that you maintain your same fitness level, meaning your lactate threshold occurs at the same percent of your VO2max. If this happened, with a decrease in VO2max, then you’d get slower. BUT there is efficiency (or economy). There are limited studies that have looked at this over time since a longitudinal study like this is difficult to do. But there is a 5-year study of an elite woman runner whose 3000m time improved by 8% even though VO2max decreased by 9%. How? Her lactate threshold improved by 20% and her running economy improved by 11% over 5 years. To have an improved lactate threshold means you can maintain a higher speed since you are running at a greater percent of your VO2max. To have an improved running economy means you need less energy to maintain the same speed.

So you can see that VO2max is not so “almighty”. Yes, you need to have a high VO2max to be an elite athlete, but it is only one part of endurance performance.

Men and Women

Men typically have a 10% higher VO2max than women when normalized for body weight. This is because, biologically, women tend to have a lower haemoglobin concentration (associated to how much oxygen your blood can carry), higher body fat percent (relates to body weight), and smaller heart and lung size (relates to ability of heart and lungs to deliver oxygen). BUT this is true when the comparison is alike (or homogenous), meaning that you take a man who is recreationally active and compare him to a woman who is similarly recreationally active the man would likely have a higher VO2max. But, if you took a recreationally active man and compared her to a woman who is endurance trained, her VO2max would likely be higher. So size and training are important. If you compare the world’s best marathon male to a female than the male will likely have a higher VO2max.

Contact me if you want to know more or have any questions!


References and further scientific reading:

  • Galy O, Chamari K, Costes O, Hue O, Maimoun L, Manetta J. Maximal oxygen uptake and power of lower limbs during a competitve season in triathletes. Scand J Med Sci Sport. 2003;13(3):185-193.
  • Hopker J, Coleman D, Passfield L. Changes in cycling efficiency during a competitive season. Med Sci Sports Exerc. 2009;41(4):912-919.
  • Jones AM, Carter H. The effect of endurance training on parameters of aerobic fitness. Sports Med. 2000;29(6):373-386.
  • Jones AM. A five year physiological case study of an Olympic runner. Br J Sport. 1998;32(0306-3674 (Print)):39-43.
  • Joyner MJ, Coyle EF. Endurance exercise performance: the physiology of champions. J Physiol. 2008;586(1):35-44. doi:10.1113/jphysiol.2007.143834.
  • Klitgaard A. Effects of detraining on endurance capacity and metabolic changes during prolonged exhaustive exercise. 1993.
  • Madsen K, Pedersen PK, S DM, Klitgaard NA. Effects of detraining on endurance capacity and metabolic changes during prolonged exhaustive exercise. J Appl Physiol Appl Physiol. 1993;75(4):1444-1451.
  • Mendes TT, Fonseca TR, Ramos GP, et al. Six weeks of aerobic training improves VO2max and MLSS but does not improve the time to fatigue at the MLSS. Eur J Appl Physiol. 2013;113(4):965-973.
  • Passfield L, Doust JH. Changes in cycling efficiency and performance after endurance exercise. Med Sci Sports Exerc. 2000;32(11):1935-1941.
  • Term L, Training I. Detraining : Loss of Training-Induced Physiological and Performance Adaptations . Part II. 2000;30(3):145-154.