Because of the pregnancy-induced ch

Because of the pregnancy-induced changes affecting exercise heart rate response, the most accurate and safest way to gauge exercise intensity is to use the Borg rating of perceived exertion (RPE). Pregnant women should exercise at a level that feels moder-ate to somewhat hard (12 to 14 on the 20-point scale or 3 to 4 on the 10-point scale). Some women may not be able to accurately gauge their exertion level, especially if they are just starting an exercise program, so a comparative tool is to advise clients to avoid exercising to the point where they are unable to carry on a conversation (the “talk test”). If they are so out of breath that they cannot talk, it is a sign that they are working past the advised Borg rating range for pregnancy. Cue clients to reduce their intensity if they feel breathless, and instruct them on how to use the Borg scale to help them quantify their intensity rating. High-intensity exercise over 90% of maximal maternal HR should be avoided as somedata suggest fetal blood flow is compromised at this level (Salvesen, Hem, and Sundgot-Borgen, 2012). The use of the prenatal perceived exertion Borg parameters or talk test will prevent women from reaching the high-intensity threshold during exercise.