VO2 max is the maximal volume of oxygen your body can absorb and consume during physical activity. Improving your VO2 max can extend the amount of time that you can work out intensely, set a standard for your fitness level, raise your anaerobic threshold, and help determine your cardiorespiratory fitness and the amount of ease you have performing certain workouts. You can measure your VO2 max in two different ways. The first is to go to a specialized laboratory and have them do it. The second is to work with a fitness instructor or sports medicine physician with a VO2 max testing certification who can determine your score through an exercise test. At a laboratory, they have dedicated equipment to figure out your VO2 max, including treadmills and oxygen masks. A fitness instructor has less formal procedures, but they can still find your VO2 max, although it will not be as precise. Your age, sex, body composition, fitness level, and other factors can affect your VO2 max. There are multiple ways to take your VO2 max test, depending on your fitness level: 1. __Cooper 1.5 mile run test:__ Find a long and flat running surface, like a track, and have a trainer monitor your results with a stopwatch. Run the 1.5-mile course in the shortest time possible. By plugging your weight and time into an online VO2 max calculator for a Cooper 1.5 mile run test, you can roughly determine your VO2 max level. Compare it to an online chart, making sure to adjust for your age, bodyweight, and sex. 2. __Bruce protocol treadmill test:__ With a trainer or fitness instructor, set a treadmill at 1.7 miles per hour and a 10 percent grade. The grade and speed both increase every 3 minutes, with the final stage sitting at 6.0 mph and a 22 percent grade. The test concludes when your heart rate goes above 115 beats per minute for two stages, your heart rate exceeds 85 percent of your max heart rate, or your instructor tells you to stop. Use an online calculator to determine your VO2 max level and compare it to an online chart, making sure to adjust for your sex, bodyweight, and age. 3. __Astrand treadmill test:__ Begin walking on the treadmill with a zero percent incline. Once you reach 5 miles per hour, tell your trainer to start the stopwatch. Then go for 3 minutes. Adjust the grade to 2.5 percent at the end of the 3 minutes, and have your trainer add a lap to the stopwatch. Run for 2 minutes, adjust the grade another 2.5 percent, and then go another 2 minutes. Repeat the 2.5 percent grade increase/2 minute pattern until you’re unable to continue. Then, once you’ve recovered, calculate your VO2 max by using this formula: __VO2 max = (Time x 1.444) + 14.99__. Compare your results to an online chart, and make sure to adjust for your age, bodyweight, and sex. Whether you are an athlete, fitness enthusiast, or just want to get healthier, knowing your VO2 max metric is beneficial for several reasons. A good VO2 max score can improve: 1. __ATP energy__: When you inhale, your lungs convert oxygen to adenosine triphosphate (ATP). This compound is present in your body’s tissue, and when it’s broken down, it gives your body the energy it needs to perform. Your body uses the energy for all activities, from cardio to sitting on the couch. Having higher VO2 max values means you can consume more oxygen, create more ATP energy, and make aerobic workouts easier. 2. __Aerobic fitness level__: Knowing your VO2 max helps you determine your fitness level and trainability. It also shows your aerobic fitness level and aerobic endurance level. This is particularly important for athletes who participate in endurance training programs and compete in endurance sports, as they need to take in the maximum amount of oxygen possible. 3. __Stress reduction:__ Exercising regularly—and thereby raising your VO2 max level—reduces stress, boosts your immune system, and gives you more energy. Increasing exercise intensity augments your heart rate and can boost your VO2 max. To improve your VO2 max score, integrate a form of high-intensity interval training (HIIT) into your training plan, such as: 1. __Running__: Run as hard as you can for 30 seconds, then run normally or even walk for 1–2 minutes. Repeat this process 3–5 times, for a total of 10 minutes. 2. __Hill running__: Find a hill in your neighborhood or nearby with a good grade—something challenging but not overwhelming. Run as hard as you can up the hill, then run slowly downhill until you get back to where you started. Repeat the process at least 4 times. 3. __30/30 interval workouts__: Run as hard as you can for 30 seconds, then jog for another 30 seconds to cool down. Repeat 12–20 times. Cyclists can use this same technique on their bike, as can rowers with rowing. If you have a previous or pre-existing health condition, consult your physician before beginning an exercise program. Proper exercise technique is essential to ensure the safety and effectiveness of an exercise program, but you may need to modify each exercise to attain optimal results based on your individual needs. Always select a weight that allows you to have full control of your body throughout the movement. When performing any exercise, pay close attention to your body, and stop immediately if you note pain or discomfort. In order to see continual progress and build body strength, incorporate proper warm-ups, rest, and nutrition into your exercise program. Your results will ultimately be based on your ability to adequately recover from your workouts. Rest for 24 to 48 hours before training the same muscle groups to allow sufficient recovery. Throw on some athleisure, fire up a [MasterClass Annual Membership](https://www.masterclass.com), and get ready to sweat it out with exclusive instructional videos from Nike Master Trainer and *GQ* fitness specialist Joe Holder. Want to improve your cardiovascular endurance? Give Joe’s HIIT workout a go. Trying to get a little swole? He’s got a strength training workout for that. From fitness tips to nutrition hacks, Joe will have you feeling healthier in no time. Learn how to measure and improve your maximal oxygen consumption.