Which Comes First, Cardio or Weights_ - Alex Hutchinson [26]
So other than satisfying curiosity, what does testing your VO2max tell you? Comparing the results of several tests over time does allow you to monitor whether you’re improving or not—but then again, so does entering races. For most athletes, experts recommend lactate threshold testing as a more useful training tool.
What is “lactate threshold” and should I have mine tested?
Scientists are still arguing about the physiology of the lactate threshold and how it should be defined, but the basic concept is straightforward. If you’re running or biking along at a slow pace and you’re reasonably fit, you should feel like you could continue for hours. If you’re going very fast, you’ll feel like you need to stop or slow down within a few minutes. Somewhere between those two paces, there’s a point beyond which you begin burning energy at a rate that you can’t sustain, and that point is marked by a dramatic increase in the rate at which lactate accumulates in your blood.
This threshold typically corresponds to the pace you could maintain for about an hour, and it’s accompanied by other physiological indicators; for instance, you’ll start breathing much more heavily, which is why the “Talk Test” (see Chapter 4) can be used as a rough guide to find your threshold. The pace you’re going when you hit that threshold is the best indicator scientists have to predict how you’ll fare in a race, and it’s also a valuable guide for figuring out how fast you should go in workouts—which is why many athletes use regular lactate testing to monitor progress and guide training.
Scientists originally believed that lactate was a harmful waste product that caused pain and fatigue—but they were confusing correlation with causation. Lactate levels rise when your muscles are in “oxygen debt,” or forced to burn energy less efficiently because they can’t get enough oxygen—but lactate is actually a fuel rather than a waste product. Still, you can use the rise of lactate levels in your blood as a rough indicator of when you’re making the transition from relying mostly on aerobic metabolism (your muscles are getting enough oxygen to keep going) to anaerobic metabolism (they’re no longer getting enough, so you can’t continue indefinitely).
Like the VO2max test, a lactate threshold test involves exercising on a treadmill or stationary bike with the speed gradually increasing. Lactate tests typically last between 20 and 60 minutes, with the speed staying constant for about five minutes at a time. At the end of each stage, a pinprick of blood is extracted from the fingertip or earlobe. Absolute values of lactate aren’t very significant, because the number can vary depending on how the measurements are made or even what you’ve eaten beforehand. Instead, the significant result is your speed (and heart rate) when lactate levels start to increase dramatically. This is your lactate threshold.
A 2009 review in the journal Sports Medicine surveyed 32 studies of the link between lactate threshold and racing performance in running, cycling, race walking, and rowing. The results showed that lactate threshold was far more accurate than VO2max at predicting results, accounting for between 55 and 85 percent of variance in running distances from 800 meters to the marathon.
Lactate threshold is also more sensitive to training than VO2max, so it’s an ideal tool to monitor training. Adam Johnston, a coach and the director of the Endurance Lab in Toronto, has the athletes in his WattsUp Cycling program take lactate tests every four months. “It’s very empowering for the athlete to see the definite differences after four months of training,