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Blood Lactate Testing and Vo2 Testing: What's the Difference and How They Can Help Your Training.

Blood Lactate Testing and Vo2 Testing: What's the Difference and How They Can Help Your Training.

Blood Lactate Testing and Vo2 Testing: what’s the difference and how they can help your training.


The biggest bang for your buck as an amateur athlete comes through performance testing to determine your heart rate zones and how your body works within those zones. Here at Playtri have over 20 years of experience coaching and administering performance testing to help athletes improve their training and reach their goals. Because of this long history, we have a lot of real-world application and data that supports the importance of performance testing for amateur athletes. However, there can be some confusion about which tests will help you the most in your training. And the two tests that often get confused are blood lactate testing and Vo2 testing.


Blood Lactate Testing is the most accurate way to determine your heart rate zones for training and racing. Using our proprietary blood lactate testing protocol and backed by 20+ years of in-house research and testing, we use this test to give athletes accurate heart rate zones. We strongly recommend this for all athletes trying to work within or create a structured training plan and we require this for all our individually coached Playtri athletes. Lactate which is a byproduct of energy production, builds up in the blood faster than it can be removed when you cross your blood lactate threshold and makes you feel like you need to stop exercising immediately. As endurance athletes, knowing your sustainable heart rate level is incredibly important, since even the shortest triathlons are still aerobic events.


At Playtri, we offer different Vo2 tests. We offer the traditional Vo2 Max test and a Vo2 Calorie Expenditure test. The Vo2 max test is used when an athlete wants a measurement of their current performance potential. Although it is generally considered the best indicator of cardiovascular fitness and aerobic endurance, we do not recommend it for determining heart rate zones. Vo2 max is a measurement of your cardiovascular efficiency or the maximum volume of oxygen you can use at your maximum effort. Your Vo2 max is not a static number. As your fitness improves or declines, your Vo2 max will change. For example, an athlete new to endurance sports will see an increase in their Vo2 max through swimming, biking, running, and walking. Whereas a more seasoned endurance athlete will likely need to incorporate intervals of 30 seconds to 3 minutes at an intense effort followed by solid recovery to increase their Vo2 max. However, it can only increase so much because of the influence of genetics. (Thank your parents for that.) This is why we recommend Blood Lactate Testing for determining heart rate zones.


Knowing this, we encourage our individually coached athletes who have time-specific or high-performance goals to do both blood lactate testing and Vo2 Calorie Expenditure testing. Vo2 Calorie Expenditure testing differs from Vo2 Max testing in this way: while Vo2 max gives you a number indicating your performance potential, Vo2 Calorie Expenditure testing determines how much fat and carbohydrates you burn during a bike or run, based on different heart rate levels. This is our “secret weapon” for long-course athletes and those looking to lose weight and/or maximize recovery nutrition for high-level training because the test report provides you a breakup of your calorie expenditure at different heart rates, allowing you and your coach to best determine how much you need to consume during training and racing.


If you know you want to train smarter via performance testing but aren’t sure where to start, or want to learn more about our different coaching options, please feel free to contact me at Happy training and racing!


Jim Rowe is a Playtri Level 4 Coach and Coach Education Lead, a USAT LI Certified Coach, an NASM Certified Personal Trainer, and an Ironman and 70.3 World Championship Qualifier who works with adult athletes of all abilities from beginners to IRONMAN World Championship qualifiers. Learn more about Jim at


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