Researchers at the University of Wisconsin-La Crosse showed for the first time that the “talk test” is an accurate gauge for your exercise intensity. When treadmillers in the study reached the stage of where they needed to take a breath every few words during a conversation, “they were in their ventilatory threshold, the point at which could be very difficult to maintain that level of exertion for too long”, says John Porcari Ph.D. When you are in this high intensity zone, lactic acid begins to build in your muscles and your body fatigues faster. If you can barely utter a full sentence then you are at the right intensity to squeeze more minutes from your cardio session.
Fitness Magazine July/August 2011