Effective Ways to Boost Your Exercise Performance

What is VO₂ max?

VO₂ max is the maximum amount of oxygen your body can utilize during intense exercise. And it’s the best measurement of cardiorespiratory fitness, reflecting how efficiently your heart and lungs deliver oxygen to your working muscles. VO₂ max also tells you how well your muscles can use that oxygen to generate energy.

The best way to measure your VO₂ max is in a laboratory setting. A tightly fitted mask or breathing snorkel is worn and connects to a bulky oxygen reading machine as the athlete exercises at full effort while working out on a treadmill, stationary bike, or rowing machine.

This machine then calculates your VO₂ max based on oxygen delivery (air exchange in the lungs, pumping power of your heart, and arterial blood flow to your muscles) and also oxygen demand by the tissues in your body.

Mitochondria—those little energy factories found in every one of your cells—are a major factor in the oxygen delivery portion of VO₂ max (mitochondria power the heart) and in the oxygen demand (how many mitochondria are in the muscles). In less conditioned athletes, VO₂ max tends to be mostly limited by oxygen demand (less muscle mass and fewer mitochondria in untrained people). Elite athletes, on the other hand, have more muscle mass and considerably more mitochondria. So, while you can use this test to see how efficiently your body uses oxygen while you exercise, VO₂ max is actually an estimate of your mitochondrial density.²

Having your VO₂ max tested in a lab is the most accurate way to assess your fitness level, but it does come at a cost. Depending on your area and the facilities available, expect to spend anywhere from $100 to $250.³ However, you can also do a DIY test called the Cooper test, that can give you a good idea of where you stand fitness-wise. Also known as the 12-minute run test, the Cooper test is designed to estimate a person’s cardiovascular endurance and VO2 max. It involves running or walking as far as possible in 12 minutes. The distance covered is then used to estimate an individual’s aerobic fitness level.⁴

To complete a Cooper test, you should walk or run, without interruptions, for 12 minutes. You can do this on either a treadmill or running track, and you should aim to keep the same pace throughout the test. After 12 minutes, note the total distance you’ve covered. To calculate VO₂ max from the distance covered in 12 minutes, enter your distance in meters (D) into the following formula: VO₂ max = (D – 504)/ 45. If that feels a bit too complicated, you can simply use an online calculator like this one that gives you the option to use kilometers or miles.

What the Numbers Mean

Here are two charts that can help you figure out your cardiorespiratory fitness levels base on your VO₂ max results—one for men and one for women—and your age.⁵

How to Improve Your VO₂ max

If your VO₂ max or Cooper test results could be better, don’t despair. You can improve your cardiorespiratory fitness with training. Focus on regular aerobic exercise, particularly

high-intensity interval training (HIIT), as well as endurance training. HIIT involves short bursts of intense exercise followed by brief recovery periods, while endurance training involves consistently pushing your endurance limits. Switching up your workouts by incorporating different types of aerobic activities (e.g., running, cycling, swimming) can help prevent plateaus and keep your body challenged.

Maintaining a healthy weight can indirectly improve your VO₂ max as well, but it’s important to distinguish between gains due to training and those solely from weight loss, according to Harvard Health. And don’t forget to prioritize your recovery through adequate sleep.

Consider Supplementing

There are a number of supplements reputed to enhance exercise performance, however few have rigorous clinical evidence supporting their effectiveness. That said, there are several that studies suggest may improve VO₂ max. Here are three with scientific credibility that you may want to consider adding to your workout routine.

Aged Garlic Extract (AGE) was recently shown to provide long-term performance benefits for the long distance athlete. In a double-blind, parallel, randomized study involving 75 middle-aged endurance athletes, AGE was found to boost VO₂ max, increase arterial flexibility and aerobic power, decrease fatigue, and reduce post-workout recovery time. These benefits weren’t seen in those taking the placebo. The participants taking AGE also had a lower risk of cardiovascular disease compared to those in the placebo group.⁶

Earlier research found that AGE improves blood pressure and arterial stiffness, effectively “rejuvenating” the arteries that carry nutrient- and oxygen-rich blood to all the tissues and organs in the body, including muscles, thanks to its active compound S-allylcysteine (SAC).⁷ SAC is formed by the enzymatic conversion of gamma-glutamyl-S-allylcysteine (GSAC) when garlic undergoes the aging process. The result is a powerful antioxidant and anti-inflammatory compound that provides a variety of heart healthy benefits that can improve your fitness level and exercise capacity.

Ashwagandha is a popular adaptogen that some studies suggest can enhance VO₂ max. During one meta-analysis, a group of Spanish researchers systematically reviewed nine studies and concluded that a daily dose of ashwagandha improved VO₂ max in both athletes and healthy non-athletic people.⁸  This calming herb has also been found to enhance muscle strength and coordination as well as cardiorespiratory endurance.⁹

Rhodiola is another adaptogen that may help increase exercise performance. Research suggests that rhodiola can increase physical performance and endurance in professional athletes while helping to build new muscle tissue.¹⁰ There’s also some evidence that, when taken 60 minutes before a workout, rhodiola may improve time to exhaustion and time trial performance, which could indirectly impact VO₂ max.¹¹

If you’re an endurance athlete looking to up your game, knowing your VO₂ max can provide an excellent tool to track your progress. If your VO₂ max and cardiorespiratory fitness could use a boost, try focusing on HIIT and endurance workouts, maintaining a healthy weight and getting a sufficient amount of sleep. You can also take your performance to the next level with clinically proven supplements like aged garlic extract.

1. Walking is the most popular exercise activity. Spotlight on Statistics. U.S. Bureau of Labor Statistics. https://www.bls.gov/spotlight/2017/sports-and-exercise/#:~:text=From%202009%20to%202015%2C%20of,running%20on%20days%20they%20exercised.
2. LeMond G, Hom M. 10 – Gauging fitness. The Science of Fitness. Academic Press, 2015. Pages 117-43.
3. Tests offered at the UF Health Sports Performance Center. University of Florida. https://ufhealth.org/locations/uf-health-sports-performance-center/tests-offered-at-the-uf-health-sports-performance-center#aerobic-fitness-testing-vo2max
4. 50 years of the Cooper 12-minute run. 2018. https://www.cooperinstitute.org/blog/50-years-of-the-cooper-12-minute-run
5. Bruce C. Cooper test: What it measures, how to complete & results. 2025. https://www.tuasaude.com/en/cooper-test/
6. Ried K, Paye Y, Beale D, et al. Kyolic aged garlic extract improves aerobic fitness in middle‑aged recreational endurance athletes: A randomized double‑blind placebo‑controlled 3 month trial. Experimental & Therapeutic Medicine. 2025;29(4):86.
7. Ried K, Travica N, Sali A. The effect of aged garlic extract on blood pressure and other cardiovascular risk factors in uncontrolled hypertensives: the AGE at Heart trial. Integrative Blood Pressure Control. 2016 Jan 27;9:9-21.
8. Pérez-Gómez J, Villafaina S, Adsuar JC, et al. Effects of ashwagandha (Withania somnifera) on VO_2max: A systematic review and meta-analysis. Nutrients. 2020;12(4):1119.
9. Guo S, Rezaei MJ. The benefits of ashwagandha (Withania somnifera) supplements on brain function and sports performance. Frontiers in Nutrition. 2024;11:1439294.
10. Lu Y, Deng B, Xu L, Liu H, Song Y, Lin F. Effects of Rhodiola Rosea supplementation on exercise and sport: A systematic review. Frontiers in Nutrition. 2022;9:856287.
11. Tinsley GM, Jagim AR, Potter GDM, et al. Rhodiola rosea as an adaptogen to enhance exercise performance: a review of the literature. British Journal of Nutrition. 2024;131:461-73.

This article is for informational purposes only. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice.