Health / Pregnancy

Is It Safe to Practice Interval Training While Pregnant?

Find out how you can safely include interval training during your pregnancy.

Interval training has become an increasingly popular fitness trend. It efficiently trains the body to increase fat burning and improve aerobic capacity in just a 20-30 minute workout.

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Due to its high-intensity nature, women may question whether it’s safe to continue interval training while pregnant. There’s a theoretical concern that intense prenatal exercise may shunt blood flow away from the fetus for periods long enough to impact growth and development. But, with interval training, the duration of intense exercise is short and allows for a recovery period. This avoids a sustained period of reduced fetal blood flow. Keep reading to find out more about practicing interval training while pregnant—and how to do so safely.

Consider the different types of interval training.

There are many different types of interval training, from HIIT to variations in running sprint work. But for the most part, they all encompass short, alternating bursts of intense exercise that last approximately 20-30 seconds depending on the intensity. It’s followed by a period of lower intensity exercise or rest. Interval training can be built into a running, walking, cycling, or stationary exercise equipment exercise routine, or any activity that you can easily modify the intensity. Just include several sessions each week where you do sets of short, high-intensity exercise, followed by a recovery period. The number of sets and ratio of intensity to rest that you choose is up to you and your fitness goals.

Monitor your exertion levels.

No matter what type of interval training you perform while pregnant, you’ll need to monitor your exertion level carefully. According to Maura Shirey, RN, CPFE, and owner of Bodies for Birth, interval training while pregnant is at the heart of the Bodies for Birth fitness program. Her instructors modify the routine to fit each client’s level of fitness and ability. Their program includes low-impact, moderate intensity intervals, using a progressive model that uses equal effort to rest ratios. As the student progresses, the number and duration of intervals are increased. Shirey says, “At Bodies for Birth, interval training is intentionally designed to mimic the effort needed for labor and delivery. We use interval training to help women prepare the mind and body for the effort needed during birthing.”

Shirey suggests pregnant women learn how to use the Rate of Perceived Exertion 1-10 scale (RPE). Generally, pregnant women should maintain a moderate level of exercise intensity of four to five on the scale for their sustained cardio exercise. With interval training, the limit shouldn’t exceed six to seven.

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Shirey stresses that safely maintaining interval training while pregnant consists of two key points. Keep your exercise intensity in the safe RPE zones. Secondly, monitor yourself for signs that your exercise routine is becoming too difficult. As with any activity, the harder you work, the higher the risk of injury, especially if you don’t pay attention to your body’s signals.

Stay mindful of how your body feels.

A 2016 study published in the British Journal of Sports Medicine offers encouraging data regarding the effect of intense exercise on pregnancy. The researchers found that there’s strong evidence that high-intensity exercise doesn’t appear to increase the risk of premature birth, forcep-assisted birth, vacuum deliveries, and/or the need for a cesarean section, or C-section. The babies of women who exercised at more vigorous levels during their pregnancy weighed less (and were less fat) than those of non-exercising moms. But they were still within normal limits. The authors caution that pregnant women should think “maintain, not build” regarding their exercise routine. They should also pay close attention to physical symptoms that may signal that they’re overdoing it.

Symptoms That Your Exercise Routine Is Too Hard

Also, if you aren’t gaining weight at the rate that you should be, or the growth of your fetus doesn’t measure within normal limits, check with your healthcare provider about whether you should continue with your exercise routine.

Tips For Safe Interval Training While Pregnant

Always clear your exercise program with your healthcare provider. Although the American College of Obstetricians and Gynecologists recommend that pregnant women take part in an exercise program, some conditions make exercise during pregnancy unsafe.

As pregnancy progresses, most women will need to make exercise modifications to enable them to continue interval training safely. Modifications include: lowering the intensity level of the intervals, reducing interval duration, and increasing the rest period. If signs of exertional intolerance continue even with modifications, interval training should be discontinued. Maura Shirey feels that at 37 weeks, most pregnant women should ease up on their interval training so that their bodies are well-rested and ready for labor and delivery.

Once you ease up on exercise, you can continue to give time to your mental health with meditation. Aaptiv has meditation classes on a wide variety of topics. 

How Can I Modify My Interval Training?

Health Pregnancy


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