Activities to Perform During Pregnancy

Most guidelines recommended activities to engage in during pregnancy. All but the French and Spanish guidelines indicated duration or total time and all but the Australian and French guidelines indicated frequency of physical activity. For most guidelines, intensity was indicated as moderate or vigorous, or in absolute (e.g., heart rate) or relative (e.g., rating of perceived exertion) indicators.

Guidelines
	Australia	Canada	Denmark	France	Japan	Norway	Spain	United Kingdom	United States (ACOG)	United States (USDHHS)
General Exercise Recommendations:
Cool down		X				X	X
Duration or total time, specified	X	X	X		X	X		X	X	X
Drink water or stay hydrated	X	X				X	X
Flat place					X
Frequency, specified		X	X		X	X	X	X	X	X
Intensity:
Moderate		X	X	X		X			X	X
Vigorous		X	X							X
Absolute (heart rate)		X			X		X	X
Relative (RPE)		X			X	X		X
Start new exercise program	X	X	X	X	X	X	X	X		X
Time (10am–2pm)					X
Warm-up		X				X	X
Wear light clothes						X
Examples of Specific Activites To Do:
Aerobic activities	X	low impact	implied by duration and intensity		X	X	X	X	implied by duration and intensity	X
Cross country skiing		X
Nordic walking						X
Pelvic floor exercise		X	X			X
Stationary cycling		X					X
Strengthening	X	X	X			X		X
Stretching	X	X			X	X
Walking		X			X	X	X
Water exercise, swimming	X	X			X	X	X	X
Yoga					X
Examples of Activites To Do With Caution:
Bowling							X
Cross country skiing							X
Horseback riding							X
Golf							X
Gymnastics							X
Jogging, mild							X
Racquet sports							X

RPE = rating of perceived exertion

Type

All but the French guidelines specified aerobic activities as an acceptable modality. Guidelines from Australia, Canada, Denmark, Norway, and the United Kingdom also recommended strengthening exercises. Only Spain provided a list of activities to perform with caution.

Frequency and Duration

Most guidelines (with the exception of those from France) included information on frequency and/or duration of exercise. Specifically, Canada and the United Kingdom indicated a minimum of 15 minute sessions for 3 times per week, progressing to 30 minutes, 4 times per week even if intensity was reduced. Denmark recommended at least 30 minutes of moderate intensity activity daily. Japan recommended aerobic exercise for up to 60 minutes, 2 to 3 times per week. Norway recommended 30 minutes per day of aerobic activity. Spain recommended a frequency of 3 times per week with no duration specified. The US ACOG recommended accumulating 30 minutes or more of moderate exercise on most if not all days of the week. The USDHHS indicated that “healthy women who are not already highly active or doing vigorous-intensity activity should get at least 150 minutes (2 hours and 30 minutes) of moderate-intensity aerobic activity per week during pregnancy and the postpartum period. Preferably this activity should be spread throughout the week”.

Intensity

For absolute intensity, heart rate guidance was provided by Canada, Japan, Spain, and the United Kingdom. Guidelines from Canada and the United Kingdom specified heart rates accounting for age; however, Japan and Spain recommended heart rates less than 150 and 140 beats per minute, respectively. The Canadian guideline advised working in the lower ends of the heart rate zone if starting a new exercise program or in late pregnancy. The target heart rate zones provided by Canada represented 60% to 80% of maximal aerobic capacity. The United Kingdom guideline advocated for an “upper range of 60% to 90% maximal heart rate for women wishing to maintain fitness during pregnancy” (page 4), and 60% to 70% of maximal heart rate for women who were sedentary prior to pregnancy. The Norwegian guideline recommended that aerobic exercise intensity should not exceed 70% to 75% of maximal oxygen uptake, instead advising use of a talk test (being able to talk while exercising) or the Borg’s rating of perceived exertion scale. Canada and the United Kingdom also mentioned the usefulness of the “talk test”. The lowest guidance on intensity was from Spain, which recommended not exceeding 50% of maximal oxygen consumption.

For relative intensity, Canada, Norway, and the United Kingdom recommended perceived exertion of 12 to 14, just above or below “somewhat hard”, which generally coincided with moderate intensity. Japan recommended a perceived exertion less than 13 (somewhat hard) or 14, and for continuous exercise to be less than 11 (fairly light) or 12.

The French guideline recommended that beginning or continuing moderately intense sport physical activity during pregnancy was possible. The USDHHS guideline indicated that “pregnant women who habitually engage in vigorous-intensity aerobic activity or are highly active can continue physical activity during pregnancy and the postpartum period, provided that they remain healthy and discuss with their health-care provider how and when activity should be adjusted over time”. The Australian guideline condoned this: for healthy women not highly active or engaging in vigorous activity, then moderate intensity was recommended. The US ACOG stated that pregnant women should engage in regular, moderate intensity physical activity in the absence of contraindications.

Starting a New Exercise Program

All but the US ACOG guidelines included guidance for women starting a new exercise program during pregnancy. The Australian guideline suggested that women could begin a light to moderate exercise program in consultation with their doctor, and the Canadian guideline stated that for uncomplicated pregnancies “women with or without a previously sedentary lifestyle should be encouraged to participate in aerobic and strength-conditioning exercises as part of a healthy lifestyle”. It indicated this generally was “in the second trimester, when the nausea, vomiting, and profound fatigue of the first trimester have passed and before the physical limitations of the third trimester begin”. In Japan, the guideline indicated that if a pregnant woman started a sport during pregnancy, she should initiate it after 12 weeks’ gestation and confirm a normal pregnancy.

In Norway and the United Kingdom, women engaging in new exercise programs during pregnancy were encouraged to begin gradually with shorter sessions of 15 minutes for 3 times per week, then increase gradually to 30 minute sessions 4 times a week, and eventually to daily sessions. Spain recommended only initiating exercise slowly for previously sedentary women, but did not provide specifics. The US ACOG guideline indicated that previously inactive women should be evaluated before physical activity recommendations are made and to increase the amount of physical activity gradually over time. The USDHHS guideline also indicated that “when beginning physical activity during pregnancy, women should increase the amount gradually over time. The effects of vigorous-intensity aerobic activity during pregnancy have not been studied carefully, so there is no basis for recommending that women should begin vigorous-intensity activity during pregnancy”.

Other Exercise Guidance

The guidelines from Canada, Norway, and Spain suggested warming up and cooling down before and after exercise, respectively. Australia, Canada, Norway, and Spain also mentioned hydration during exercise. Norway’s guideline also suggested wearing light clothes during exercise. Japan’s guideline described environmental characteristics of the exercise, such as choosing a flat place and exercising between 10am and 2pm, supported by studies finding natural uterine contractions to be lower during that time period.

References:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4206837/ 

Borg G, Linderholm H. Perceived exertion and pulse rate during graded exercise in various age groups. Acta Med Scand. 1974;472:194–206.

Murooka H. Sports Medicine for Pregnant Women. Tokyo, Japan: Asakura Publisher; 1982. Required conditions and contraindications; pp. 57–70.

Germain A, Valenzuela G, Ivankovic M, Ducsay C, Gabella C, Serón-Ferré M. Relationship of circadian rhythms of uterine activity with term and preterm delivery. Am J Obstet Gyn. 1993;168(4):1271–1277.https://www.ncbi.nlm.nih.gov/pubmed/8475974

Activities to Avoid During Pregnancy

Falls or Trauma

All guidelines generally ruled-out sports involving risks of either falls, trauma, or collisions. A sport’s safety was determined based on the movements required to participate in it. One concern was that the ligaments become relaxed due to increasing hormone levels, making joints more prone to injury (Australia, Canada). The Norwegian guideline was the only one to warn against high loads during strengthening exercises due to the risk of pressure reflex.

Position

All but two guidelines (France, Spain) warned against activities in the supine position (lying on one’s back) due to the chance of decreased cardiac output and orthostatic hypotension caused by the enlarged uterus, which may obstruct venous return or blood flow from the abdominal aorta. As a result, these guidelines recommended avoiding the supine position during physical activity after the first trimester or 16 weeks’ gestation. Canada’s guideline suggested modifying the position of the exercise to instead be on one’s side, sitting, or standing. Denmark’s guidelines recommended a seated position during strength training.

Altitude and Depth

Four guidelines included recommendations about physical activity or exercise at altitude. Canada’s guideline accepted moderate exercise at altitudes up to 6000–8250 feet (1800–2500 meters). The US ACOG guideline stated that exercise up to 6000 feet (1800 meters) appeared safe, but exercise at higher altitudes carried risk. It also stated that women should be informed of the signs of altitude sickness and advised that if it develops, to stop exercising and descend from altitude to seek medical attention. Norway and the United Kingdom guideline suggested women at altitudes above 8250 feet (2500 meters) obtain 4 to 5 days of exposure at that altitude to avoid exertion and to regulate uterine blood flow. Seven guidelines specifically warned against scuba diving during pregnancy, because the fetus is not protected from decompression sickness and the fetal pulmonary circulation cannot filter bubble formation in the maternal bloodstream.

Heat and Cold

The Australian and Norwegian guideline warned of excessive body heat during exercise for pregnant women. Several other guidelines (Canada, Japan, Spain, United Kingdom) warned of exercising in hot or humid weather.

Sedentary Behavior and Motionless Standing

The United Kingdom guideline specifically mentioned avoiding a sedentary lifestyle, stating that “women and care providers should consider the effects of a sedentary lifestyle during pregnancy” (page 3) because it can contribute to a number of adverse maternal outcomes. The Norwegian and US ACOG guidelines were the only ones to advise against motionless standing due to its association with decreased cardiac output.

Avoidance of Vigorous Intensity Activity

Regarding vigorous activity, the Canadian and Norwegian guidelines cautioned against athletic competition, while the Australian guideline advised close monitoring by a physician. For both Japan and Norway, the recommended rating of perceived exertion categories did not include the vigorous intensity range. The USDHHS guideline stated that women not already highly active or engaged in vigorous activity should focus on moderate intensity activity. The Denmark guidelines cautioned against vigorous activity for women not engaged in it prior to pregnancy. These guidelines also advised that pregnant women accustomed to high intensity physical activity during pre-pregnancy could continue this activity as long as they felt well. The Spanish guideline recommended no more than 15 minutes of vigorous activity and to decrease intensity by 20% to 30% for pregnant athletes. The French guideline mentioned that women engaged in jobs that involved hard or strenuous aspects or long travel time should refer to her occupational or family physician and consider specific adjustments to job tasks.

Guidelines
	Australia	Canada	Denmark	France	Japan	Norway	Spain	United Kingdom	United States (ACOG)	United States (USDHHS)
General Activities to Avoid:
Abdominal trauma or pressure	blunt trauma	fetal trauma	X	X	X		X
Altitude		X				X		X	X
Contact or collision sports	X	X	X	X	X	4–6 months	X	X	X	X
Excessive body heat	X					X
Excessive joint stress		X		X			X
Falls or fall-related sports	X	X		X	X	X	X		X	X
Hot or humid weather	hot conditions	especially in first trimester			X	X	X	X
High impact		X		X	X		X
High loads during strengthening						X
Hyperthermia							X	X
Sedentary								X
Standing, motionless						X			X
Supine position (lying on back)	not after the first trimester	not after 16 weeks; modify position	use a seated position during strength training		not after 16 weeks	not after 16 weeks		not after 16 weeks	not after the first trimester	not after the first trimester
Uneven load during stretching		stretch with controlled movements				X	avoid extreme positions
Vigorous intensity activities		no training for athletic competition	if not done before pregnancy		implied based on Borg scale	implied based on Borg scale	no more than 15 minutes per session			if not already highly active or doing vigorous intensity activity
Examples of Specific Activites to Avoid:
Basketball					X				X	X
Bicycling outdoors	X	X						X
Combat sports (e.g., boxing, karate)							X
Floor or roller hockey							X
Gymnastics		X		X	X	X		X	X
Horseback riding		X	X		X	X		X	X	X
Ice hockey		X				X	X	X	X
Isometric exercises		X
Mountain biking			X
Mountain climbing					X
Race car driving							X
Racquet sports, vigorous				X					X
Rugby							X
Running, long distance			X
Scuba diving		X		X	X	X	X	X	X
Surfing							X
Skating						X
Skiing			X
Skiing, downhill	X	X				X	X	X	X	X
Skiing, water					X		X
Soccer							X		X	X
Volleyball					X

References:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4206837/ 

Contraindications to Exercise During Pregnancy

Guidelines from Canada, Japan, Spain, and the US described contraindications to exercise in absolute and relative terms; however, guidelines from Norway and the United Kingdom did not make these distinctions.

Absolute contraindications refer to conditions where exercise is not recommended, whereas relative contraindications refer to conditions where the risks of exercise may exceed the benefits.

Generally, where two or more countries identified contraindications, they agreed on whether it was an absolute or relative contraindication.

The six countries (Canada, Japan, Norway, Spain, United Kingdom, US ACOG) agreed on several contraindications to exercise including anemia, persistent bleeding, cardiovascular disease, cerclage or incompetent cervix, multiple gestation, preeclampsia or pregnancy induced hypertension, premature contractions or labor, premature rupture of membranes, and thyroid disease. Four or five of the six guidelines identified contraindications for diabetes mellitus, eating disorder, morbid obesity, and placenta previa.

Guidelines
	Canada	Japan	Norway*	Spain	United Kingdom*	United States (ACOG)
Absolute Contraindications:
Abnormal amniotic fluid		X
Bleeding, persistent	2nd–3rd trimester	X	months 4–9	X	2nd–3rd trimester	2nd–3rd trimester
CVD	serious	X	X	active CVD, cardiac failure, rheumatic disease	X	hemodynamically significant
Cerclage, incompetent cervix	X	X	X	X	cervical weakness	X
Diabetes mellitus	uncontrolled type 1
Fetal abnormality				X
Fetal growth restriction		X		X
History of fetal growth restriction	X				X	reduce in 2nd–3rd trimester
History of miscarriage, >=3		X
History of preterm birth				X
History of preterm labor					X	reduce in 2nd–3rd trimester
Hypertonia, poorly controlled			X
Infectious disease, acute				X
Lung disease, restrictive			X	X	X	X
Multiple gestation	triplets and higher	X	X	X	X	X
Placenta previa	symptomatic bleeding	X		X	after 26 weeks	after 26 weeks
Preeclampsia, pregnancy induced hypertension	X	X	X	X	X	X
Premature contractions or labor	X	X	X	X	X	X
Premature rupture of membranes	X	X	X	X	X	X
Respiratory disease, serious	X			pulmonary embolism
Rh+/Rh− immunologic disorder				X
Systemic disorder, uncontrolled	X
Thyroid disease, uncontrolled	X
Thrombophlebitis				X
Relative Contraindications:
Anemia	hemoglobin <100 g/L	or other bleeding disorder	X	severe	hemoglobin <100 g/L	severe
Arrythmia		X	non-assessed		unevaluated	unevaluated
Bronchitis, chronic	X		X		X	X
Cardiovascular disorder, mild to moderate	X		X	X
Diabetes mellitus		X	poorly controlled		poorly controlled	poorly controlled type 1
Eating disorder	X	anorexia	X		X
History of extremely sedentary lifestyle		X			X	X
History of fetal growth restriction		X
History of preterm birth	X	X
History of preterm labor	X	X
History of spontaneous abortion	X
Hypertension	X	X			poorly controlled	poorly controlled
Intrauterine growth restriction			X		X	X
Malnutrition	X		X		X
Multiple gestation, twins	after 28 weeks
Obesity, morbid (BMI >40 kg/m2)		X	X	X	X	X
Orthopedic limitation			X		X	X
Respiratory disorder, mild to moderate	X			X
Seizures, poorly controlled			epilepsy		X	X
Smoker, current			>20 cigarettes/day		>20 cigarettes/day	heavy smoker
Thyroid disease		X	X	X	poorly controlled	poorly controlled hyperthroidism
Underweight, extreme (BMI<12 kg/m2)		extreme thinness		extreme thinness		X

BMI=body mass index; CVD=cardiovascular diseaes

^*Distinction between relative and absolute contraindications not made.

Note: The Australia, Denmark, France, and USDHHS guidelines did not include contraindications, as the guidelines were all geared towards healthy women with normal pregnancies.

References:

Guidelines for Physical Activity during Pregnancy: Comparisons From Around the World. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4206837/