Almost everyone who trains for running, biking or swim competitions will want to know their VO2 max. But, there's another critical measurement: The ventilatory threshold.
While the ventilatory threshold doesn't get as much attention as the VO2 max, it could be a better predictor of athletic performance. Let's examine what the ventilatory threshold is, how endurance training affects it and whether it can be improved by training.
The Ventilatory Threshold
Your ventilatory threshold is the point when you can no longer exhale enough CO2 to clear the lactic acid that intense exercise builds up in the body, according to the American Council on Exercise. In other words, it’s the point when it feels impossible to breathe fast enough to keep going.
In athletic individuals, ventilatory threshold is, roughly speaking, the highest exertion level that can be kept up for one to two hours of training. For elite marathon runners, this measurement is close to their competition pace. For casual athletes, someone is typically below their ventilatory threshold if they can comfortably speak while exercising, and approaching it the harder speaking becomes.
VO2 Max or Ventilatory Threshold?
A person’s VO2 max is the most frequently used measurement to predict performance. It’s the greatest amount of oxygen that someone can use during intense exercise at maximum exertion. VO2 max is measured as milliliters of oxygen used per kilogram of body weight in one minute.
However, exercise physiologist Steve Magness argues that VO2 max is a poor way to measure performance because it doesn’t accurately predict athletic potential.
But, a 2012 study in the Journal of Strength and Conditioning Research concludes that the ventilatory threshold does consistently track the lactate threshold (when lactic acid climbs past the body’s ability to clear it). Therefore, training to improve ventilatory threshold would seem to be a more accurate way to determine how well someone could withstand prolonged endurance training.
Endurance Training and the Ventilatory Threshold
Eendurance training can result in increased lactate utilization by the muscles, says Lance C. Dalleck, MS, and Len Kravitz, PhD, resulting in a higher capacity to remove lactate from circulation. This is possibly because the improved capillary density around the muscles from endurance training improves blood flow, which can better facilitate the clearance of lactate to improve the athletes' ventilatory threshold. The conclusion is that measuring an athlete’s ventilatory threshold is an accurate way to predict how well they could be expected to perform in competition.
Improving the Ventilatory Threshold with Endurance Training
For anyone who wants to improve their ventilatory threshold (ability to maximally exert themselves for an extended time), the best option might be to practice steady-state endurance training. By reaching and staying at the point where lactic acid build up symptoms appear, such as shortness of breath and discomfort from muscular exhaustion - gradually the ability to clear lactic acid will improve.
Whether you're a fitness enthusiast or seasoned competitor, it's necessary to regularly train to develop a higher lactate threshold to improve ventilatory threshold.
HIIT and Ventilatory Threshold
This doesn’t mean that ventilatory threshold can only be improved by conventional endurance training. According to a 2016 study published in Science and Sports, high-intensity interval training (HIIT) significantly improved the ventilatory threshold in well-trained canoe polo competitors. HIIT is a training protocol typified by sets of short, all-out bursts of effort broken up by brief rest periods.
If you don’t have the hours to spend on typical endurance training, HIIT offers a time-efficient way to improve the ventilatory threshold and develop higher lactate tolerance for better exercise performance.