Training at specific intensities can cause physiological changes that increase your endurance and speed, research shows. Traditionally you’d need a university’s sport science lab to find the perfect intensity level for your body. But a new study from the Biomedical Institute at the University of Leon in Spain finds that your ability to talk while working out may be a reliable way to gauge your effort, too.
To understand how it works, you first need to understand the three thresholds your body hits during aerobic exercise.
Your target heart rate is where endurance athletes should do 70 per cent of their training. Over time, running at this moderate pace will develop your aerobic fitness.
Your ventilatory threshold happens when you start breathing heavily and begin to feel like you aren’t getting enough oxygen. This is the threshold that can improve your time as your body adapts to the new intensity. Aim to do about 15 per cent of your training at this level. Studies show doing more training at this rate doesn’t help much - and it’s hard to maintain, since it’s a difficult pace.
Your respiratory compensation threshold occurs when you're huffing and puffing but can barely make your legs keep running. “At the respiratory compensation threshold, you probably describe the effort in terms that your mother would not want you to use,” says Dr Carl Foster, Professor of Exercise and Sport Science at the University of Wisconsin-La Crosse, and co-author of the study published in the Journal of Strength and Conditioning Research. When you reach this point, dial it back. A steady rate at a lower threshold will increase your fitness more than quick bursts at your respiratory compensation threshold.
THE TALK TEST
You can use the “talk test” to identify when your body hits these thresholds. If you can hold a comfortable conversation, you're probably exercising at your target heart rate. When you increase your pace, the point at which your conversation is cut down to short phrases is your body’s ventilatory threshold. Once you can’t say more than a word or two at a time, your body has hit its respiratory compensation threshold.
How accurate is it? Researchers for the study put 18 well trained cyclists through two identical fitness tests. In one test they measured the above thresholds with traditional medical equipment. In the second test they asked cyclists to say a paragraph while exercising. What they found was that the cyclists’ “out-of-breathness” matched the thresholds. “From our standpoint, the TT is very useful and almost ‘idiot-proof,’” Foster says.
Twice a week, add in a ventilatory threshold run. After warming up, perform 3 minutes at your ventilatory threshold, then 2 minutes of easy jogging, for six rounds, says John Fenwood, a former Olympic runner for New Zealand and a New York City-based running coach.
