For many, VO2 max is known as the golden standard for determining fitness. Many might not know exactly what it means, but they do know, somehow, that a good VO2 max means you can run faster for longer. And they’re kind of right. But if you’re looking to improve your fitness and your focus is entirely on that statistic, you’re looking in the wrong place.
What is VO2 max?
VO2 Max, by definition, is “the maximum rate at which the heart, lungs, and muscles can effectively use oxygen during exercise, used as a way of measuring a person’s individual aerobic capacity.” It is based on a combination of:
Extraction: The ability of the lungs to extract oxygen from the air you breathe in
Delivery: The pumping capabilities of the heart
Utilization: The peripheral cells ability to extract oxygen from the blood
VO2 max is a marker of fitness – after all, the more oxygen you can take in and use, the fitter you can be – but is not terribly useful when predicting performance. Very much like how weight is an indicator of your overall build, but doesn’t tell you about your body composition.
A more useful marker for performance is your lactate threshold.
Most people know what lactic acid is. Or they’ve at least felt its effects – heavy legs, sickness in your stomach. Well, that lactate is produced all the time. Your body is then able to process it as you perform in the gym. However, at some point you reach an intensity where the lactate is produced so quickly that you can no longer process it fast enough, it builds up and your performance falls off a cliff. This tipping point is your lactate threshold.
The interesting part is that your lactate threshold kicks in at a percentage of your VO2 max – 70%, for example – and therefore it’s the consequent influx of lactic acid that slows you down, rather than your overall VO2 score. If two people have the same VO2 max, but one has a lactate threshold of 60% and the other 70%, then the latter will be able to work harder for longer.
So, if you want to get fitter, the best way is to focus on boosting your lactate threshold. Whilst it easier to measure than your VO2 max which requires a lot of wires, ventilation masks and men in white coats, it still isn’t easy to do – and not just because it’s going to hurt. Determining when you hit your lactate threshold is hard to pinpoint without the help of a medical professional. However, there is a workaround.
Training in heart rate zones
Recovery Zone – 60% to 70%
This is your happy place for active recovery. Training at the low end of this spectrum is useful for rest days when you still want to do some moving around. It allows your muscles to recover and replenish.
Aerobic Zone – 70% to 80%
Training here will help to develop your VO2 max and, in particular, your ability to transport and utilize oxygen. This is the heart rate zone you should target for your long, slower distance runs or bike rides at the weekend.
Anaerobic Zone 80% to 90%
Now we’re talking. Working out in this zone will help to improve your body’s ability to deal with lactic acid and it may also help to increase your lactate threshold. But be careful, this is high stress and should be restricted to one or two sessions a week. But when you do – go all out. Short, sharp pain now will make upcoming endurance work much, much easier.