Pregnant, our lungs filter 40% more oxygen. Cardiovascular exercise is an important benefit, as it helps improve the transport and delivery of oxygen to the lungs.
The further the pregnancy progresses, the more difficult breathing becomes at rest and even more so during cardiovascular training! The uterus pushes under the diaphragm, giving the lungs less room to expand. Fortunately, our diaphragm becomes more flexible during this period, because there is a release of the hormone called relaxin. When pregnant, our lungs filter 40% more oxygen. Cardiovascular exercise is an important benefit, as it helps improve the transport and delivery of oxygen to the lungs.
Working the Heart
To reap the maximum benefits and beneficial effects of cardiovascular exercise, it is recommended to do a minimum of 20 minutes per day (20-30 minutes per day which can be divided into increments of 10 minutes), 3 to 4 times a week. The first 10 minutes may be more demanding as the heart works harder than before pregnancy to circulate the oxygen that comes with that 40-50% increase in blood, but if your systembreathing works at aerobic capacity on a regular basis, the body adapts and exercise becomes easier after the warm-up period.
Your heart rate may increase up to 20 beats per minute faster than normal which will affect your Target Heart Rate Zone. Your target heart rate zone does not change because of your condition, but you will reach it faster with less effort. Note not only the Target Heart Rate Zone chart, but also the Perceived Exertion Level chart. These charts should be posted in your fitness facility (normally in the aerobics room), otherwise you can view them at the Canadian Society for Exercise Physiology.
The Level of Perceived Exertion chart is often the one that participants find easiest to use; just don't get past the point where you can't hold a conversation while doing your exercise. When you are pregnant, a level of perceived exertion between 12 and 14 will provide you with the recommended cardiovascular benefits. The target heart rate zone is between 135-150 for a woman between 20 and 29 years old, and between 130-145 for a woman between 30 and 39 years old. One should not push oneself to the point where the heart could beat too quickly in order to avoidpalpitations, dizziness, or other discomfort. Avoid the overexertion that can lead to hyperventilation: now is not the time to try to break physical performance records!
It is important to warm up well before your cardiovascular or muscular routine, and to return slowly to a relaxation phase after the effort.
Make sure you are well hydrated by drinking water before, during, and after your workouts. It is strongly advised not to do your exercises outside when it is hot or too humid; it is therefore recommended that you do your exercises in a room with air conditioning. You must avoid overheating the body, because if you are too hot, the fetus will also be too hot.
Finally, prenatal/postnatal exercise videos can be very convenient for those who don't have the time or energy to go to the gym or outdoors for their physical training. However, avoid products that are not designed specifically for pregnant women unless you have used them several times and know how to adapt the exercises to the physical changes your body goes through each trimester.