Athletes or lifelong-trained athletes may be tempted to pursue high-intensity training during pregnancy, judging that their physiological abilities will allow them to adapt to these efforts also during this period without representing risk to the gestational process. However, this assumption is far from being supported by scientific research.
The latest guidelines from the American College of Gynecology and Obstetrics maintain the recommendation that healthy women exercise at moderate intensity during pregnancy and emphasize the need for greater oversight in the case of former athletes because of their tendency to ignore these recommendations. These guidelines do not recommend greater exercise intensity in pre-trained women, recommendations recently supported by the International Committee of Experts on Pregnancy (2016).
This scientific caution behind intensive exercise recommendations is due to several existing studies aimed at assessing the impact of high training on training (given the duration and intensity of exercise) on maternal and fetal well-being and its low methodological quality.
This shortage of studies is not due to the general disinterest of the researchers but to the reasonable uncertainty caused by the results of the studies before the Ethics Committees of Scientific and Research Bodies responsible for approving new experimental studies in this field.
Risks associated with high pregnancies
Previous studies conducted by female athletes and elite athletes, who last trained on average 22 hours a week before pregnancy, suggest that high-intensity exercise (over 85% of mother's maximum capacity) can cause significant falls in fetal heart rate. , a reduction of between 60-80% of blood flow to the uterus, weight loss in intensity increases during the first and third trimesters of pregnancy, as well as a tendency to improve the timing of childbirth in pregnant women. ojchinja.
But not only the intensity must be taken into account, but also the duration. A study of more than 85,000 women linked excess minutes to minutes of physical exercise per week with an increased risk of severe preeclampsia, especially when the time exceeded 4.5 hours per week.
In addition to the same lines, another study of more than 90,000 women assessed the risks associated with high-intensity, high-intensity exercise per week, and found that those women who trained more than 7 hours per week mainly performed high-impact exercises on the field, they have increased the risk of miscarriage by almost 4 times. This risk disappeared after the 18th week of pregnancy, which coincides with the risk of miscarriage already associated with physical exertion during implantation.
There are also studies that have found no side effects at high intensities of physical exercise. However, the small number of people they perform does not allow us to generalize this safety to other women, and the limitations in their research designs justify caution in interpreting these results.
As for strength training, published studies warn that the burden of scientifically validated training does not match the high weights trained by female athletes. Performing the Valsalva maneuver during weight lifting results in a rapid rise in blood pressure and intra-abdominal pressure, temporarily causing a decrease in fetal blood flow and an increased risk of pelvic floor damage.
Despite these potential risks associated with a heavy workload, the small amount of evidence in this line raises many questions about their safety.
Valuable, but few existing studies of high exercise loads during pregnancy have focused on assessing the acute response to intense exercise, without analyzing its adaptations (effects) in the short, medium and long term on infant and maternal health.
It is still unknown to know what effect this temporary, high-intensity seizure may have on fetal development and well-being, and on its cumulative impact on the health of both if the woman decides to practice this exercise. during pregnancy.
Knowing the impact of high exercise loads on pregnancy outcome (weight, height, cranial circumference, cord blood pH, Apgar test and gestational age at birth) would be the first step in assessing your short-term safety.
Most of these studies focused on the third trimester of pregnancy, ignoring the answer that may exist if practiced in either of the other two trimesters; or even if interns are women with special characteristics such as being overweight, obese, with a high history of sedentary lifestyle, suffering from chronic hypertension, diabetes mellitus, or over 35 years of age. This high level of ignorance, along with the possible risks described, prevents scientists and health professionals from recommending heavy workouts during pregnancy with safety guarantees.
This high level of uncertainty is applicable to high loads of physical exercise (duration and intensity) of both aerobic and strength type. Popular HIIT modalities, cross – dress and hypersensitive exercise have little or no evidence of PubMed for its safety and benefits during pregnancy. However, there is a relentless scientific strength to the benefits and safety of regular, moderate-intensity physical exercise.
Is exercise safe during pregnancy?
Absolutely safe and effective if, in the first place, the woman presents no medical or obstetric contraindication to the practice of physical exercise; and if practiced regularly, combining aerobic and strength training with moderate intensity supervised by a professional in physical activity and sports science specialized in the field.
Health benefits include preventing obesity and intergenerational obesity (by controlling overweight), reduce the risk of hypertension and gestational diabetes, preeclampsia, depression during pregnancy, caesarean section, back pain, pain pelvic pain and urinary incontinence. This moderate workload provides maternal and fetal well-being.
The World Health Organization and the American College of Sports Medicine ensure that the evidence-based recommendations for physical exercise are undeniable and outweigh any risks.