Purpose of review: This review focuses on recent literature examining the validity and reliability of the talk test for prescribing and monitoring exercise intensity. The utility of the talk test for high-intensity interval training and recently proposed exercise training guidelines for patients with atrial fibrillation is also examined.
Recent findings: In healthy adults and patients with cardiovascular disease, comfortable speech is likely possible (equivocal or last positive talk test stage) when exercise intensity is below the ventilatory or lactate threshold, and not likely possible (negative talk test stage) when exercise intensity exceeds the ventilatory or lactate threshold. The talk test can be used to produce exercise intensities (moderate-to-vigorous intensity, 40-80% V[spacing dot above]O2 peak) within accepted Canadian Association of Cardiovascular Prevention and Rehabilitation and American College of Sports Medicine guidelines for exercise training, to monitor exercise training for patients with atrial fibrillation, and help avoid exertional ischemia. The talk test has been shown to be consistent across various modes of exercise (i.e., walking, jogging, cycling, elliptical trainer and stair stepper). It may not be practical for high-intensity interval training.
Summary: The talk test is a valid, reliable, practical and inexpensive tool for prescribing and monitoring exercise intensity in competitive athletes, healthy active adults and patients with cardiovascular disease. Healthcare professionals should feel comfortable in advocating its use in a variety of clinical and health-promotion settings.
Alex’s Notes: I commonly use the talk test in my own cardiovascular training (when I do it), and also with my clients. Even when just giving general recommendations I utilize it to explain how hard someone should be working. Intensity is a tricky deal because every single person has different characteristics such as medications, age, fitness level, etc. that complicate exercise prescription. Moreover, if you told someone to go at 40% their VO2 max or heart-rate reserve or whatever (assuming you were even able to test and establish what those values were), 95% of people – including many physical culturists – would just give you a blank stare.
Sure, you could use heart rate monitoring, but that won’t help without access to a maximal exercise test and any medications that alter heart rate or blood pressure (e.g. beta-blockers) will make heart rate monitoring useless. A rating of perceived exertion is another method of intensity prescription that is highly effective, if of course the individual is familiar with the scale, which most are not. Enter the talk test, whose general premise is that the harder you exercise, the more difficult talking becomes. While speech is still comfortable, the ventilatory threshold and lactate threshold has not been exceeded.
In fact, it has been established in both healthy individuals and those recovering or suffering from cardiovascular disease that the exercise intensity associated with comfortable speech moderate-to-vigorous intensity exercise, 46–90% VO2Max or 64–95%HRMax. So how do you determine this limit? The formal method involves reading some standardized paragraph that requires 10-15 seconds of speaking during the last 30 seconds of an incremental exercise test. But that is boring. A more fun and equally efficient method is to count as high as you can while at rest with one breath, and exercising at intensity that reduces this number by about 40% correlates to the ACSM’s moderate-to-vigorous exercise recommendation (40-60% VO2Max).
The caveat to the talk test is interval training. So if you are alternating short, intense, anaerobic exercise with less intense recovery periods, this test won’t be very accurate as respiration increases to buffer the lactate production during the high-intensity portion, which makes talking more difficult. That said, for steady-state cardio the talk test is accurate across virtually all modes of exercise (running, cycling, elliptical, etc.), and anyone should feel comfortable and confident in advising that the benefits of physical activity and the ACSM recommendations can be met simply by monitoring your ability to hold a conversation. So really, grab a friend next time you do your cardio and see who hates talking first.