Carrie A. Jaworski, MD, FAAFP, FACSMDivision & Fellowship DirectorPrimary Care Sports Medicine

University of Chicago/NorthShoreUniversity HealthSystem

Objectives Review current guidelines and theoretical concerns for

exercise in pregnancy

Gain insight into issues commonly encountered by pregnant & postpartum runners/endurance athletes

Learn return to running plan in the postpartum period

Exercise in Pregnancy In the US, 42% of

women do some exercise during pregnancy

21% continue for more than 2/3 of the pregnancy

Women with children are 1.67x more likely to quit an exercise program

Our role as healthcare providers: Help our patients maintain maternal fitness levels, while minimizing risk to fetus

Historical Perspectives

In 1950’s, women were allowed to walk one mile daily, preferably broken up into several sessions

Historical Perspectives In 1985, ACOG endorsed

safety of most aerobic exercise

Strict limitations

Duration (15 minutes)

Maximum heart rate (140)

Historical Perspectives In 1994, ACOG releases

statement that “during pregnancy, women can continue to exercise and derive health benefits even from mild to moderate exercise routines.”

Cautious approval ACOG Technical Bulletin No. 189, Feb. 1994

2002 Guidelines “In the absence of either medical or obstetrical

complications, 30 minutes or more of moderate exercise on most, if not all, days of the week is recommended for pregnant women.”

First formal recommendation to include exercise during pregnancy

ACOG Committee Opinion No. 267, Jan. 2002

Current Guidelines - 2015Regular physical activity in all

phases of life, including pregnancy, promotes health benefits. Pregnancy is an ideal time for maintaining or adopting a healthy lifestyle and the American College of Obstetricians and Gynecologists makes the following recommendations…

ACOG Committee Opinion No. 650, Dec. 2015

The fine print… Physical activity in pregnancy has

minimal risks and has been shown to benefit most women, although some modification to exercise routines may be necessary because of normal anatomic and physiologic changes and fetal requirements.

A thorough clinical evaluation should be conducted before recommending an exercise program to ensure that a patient does not have a medical reason to avoid exercise.

Women with uncomplicated pregnancies should be encouraged to engage in aerobic and strength-conditioning exercises before, during, and after pregnancy.

One should carefully evaluate women with medical or obstetric complications before making recommendations on physical activity participation during pregnancy. Although frequently prescribed, bed rest is only rarely indicated and, in most cases, allowing ambulation should be considered.

Regular physical activity during pregnancy improves or maintains physical fitness, helps with weight management, reduces the risk of gestational diabetes in obese women, and enhances psychologic well-being.

Additional research is needed to study the effects of exercise on pregnancy-specific outcomes, and to clarify the most effective behavioral counseling methods and the optimal intensity and frequency of exercise. Similar work is needed to create an improved evidence base concerning the effects of occupational physical activity on maternal–fetal health.

Studying Exercise in Pregnancy IRB approval is difficult (vulnerable population)

Randomized controlled trials are difficult Double blinding is impossible!

Exercise intervention must be defined – type, duration, intensity

Recommendations are often based on retrospective and case studies or on assumptions based on what we know about the effects of exercise on the non-pregnant woman and the physiologic adaptations of pregnancy

Adaptations to Pregnancy

♦ Increased vascular elasticity

♦ Expanded plasma volume

♦ Increased heart chamber size, stroke volume and heart rate

♦ Increased blood flow to the skin, kidneys and reproductive tissues

Pregnancy Exercise

♦ Increased blood volume

♦ Increased heart chamber size and stroke volume

♦ Increased blood flow to the skin and muscles

♦ Increased ability to deliver oxygen and nutrients to tissues

Cardiovascular System

Physiology- Maternal Adaptations Cardiovascular:

-Cardiac output increases by up to 50%

-Resting heart rate rise of 15 bpm

-Blood volume increases ~45%

-Stroke volume increases ~30%

-Mean arterial blood pressure falls ~10 torr

-Regional blood flow changes

Adaptations to Pregnancy

♦ Anatomy of the chest wall changes to allow for increased oxygen transport and use

Lung compliance increases as airway resistance decreases

♦ Tidal volume, minute ventilation and oxygen consumption increases(Increased resting O2

requirement)

Pregnancy Exercise

♦ No long term changes in most aspects of breathing and lung function

♦ Improves gas transfer and oxygen availability and usage at the level of microcirculation and the cell

Pulmonary System

Proposed physiologic concerns“Risk of fetal hypoxia as exercising muscle diverts

blood flow from placenta”

~50% decrease in splanchnic blood flow

Not True

Compensatory mechanisms Increased maternal hematocrit & oxygen extraction

prevent impairment Maternal exercise increases size and O2 exchanging

capacity of placenta in 1st two trimesters

Effect of exercise on placental volume

Rizk AJOG1992

Proposed physiologic concerns Supine position = 9% decrease in cardiac

output Avoid prolonged supine position after 1st trimester

High altitude = Decreased uterine blood flow Caution at > 8,250 feet until acclimated

Additional Maternal Adaptations Metabolic:

-Increased metabolic rate

-Utilize CHO at greater rate at rest and with

exercise and lower glycogen reserve

-Reduced peripheral insulin sensitivity and

hyperinsulinemia

Proposed physiologic concerns“Risk of hypoglycemia”

Decreased VO2 max secondary toincreased fetal oxygen demand andlimited diaphragm expansion = dependenceon carbohydrates as primary fuel= decrease in plasma glucose concentration

Risk with prolonged or strenuous exercise Avoid by increased intake of complex carbohydrates

Maternal Adaptations Thermoregulatory control:

Increased basal metabolic rate and heat production in pregnancy

Fetal temp 1.0°C higher than maternal oral temp

Maternal core temp decreases in pregnancy ~0.3°C in 1st

trimester

Proposed physiologic concerns

“Exercise and pregnancy both increase metabolic rate”

Maternal temperatures >102.6 F are potentially teratogenic in 1st trimester

-Core temp rises 1.5°C in non-pregnant exercising women and then reaches steady state

-Limited human studies, none with exercise (JAMA, 1992) Increased minute ventilation and skin

blood flow augment heat dissipation

Adaptations to Pregnancy

♦ Increase in body weight

♦ Change in the center of gravity

♦ Relaxin causes increased joint and ligament laxity

♦ Forces across joints double

Increased anterior pelvic tilt

Separation of abdominal muscles

Widening of SI joint and pubic symphysis

Dissipate heat more rapidly

Relatively insulin resistant

PregnancyExercise

♦ Increases muscle mass and coordination

♦ Improves ligamentous tensile strength and bone density

♦ Increased insulin sensitivity

♦ Increased ability to dissipate heat

Musculoskeletal System

Biomechanics - Pregnant Runners 20 healthy women walked on a treadmill while wearing

a custom made pseudo-pregnancy sac (1 kg) under 3 load conditions:

sac-only condition

10-lb condition (4.535 kg added anteriorly)

20-lb condition (9.07 kg added anteriorly)

Kinematic changes at the knee, hip, pelvis, and trunk in the sagittal and frontal planes

Changes may suggest that women modify gait biomechanics to reduce the effect of added load

Physiologic Concerns

Conditions seen in pregnancy– Low back pain

– Symphysis pubis pain

– Tenosynovitis of the Wrist

– Patellofemoral pain

– Leg cramps

Theoretical risks:

- Increased risk of sprains and strains

- Balance problems

No conclusive evidence of increased rates of above with exercise

Musculoskeletal issues Low back pain

Lumbosacral strain, spasm Sacroiliac dysfunction

Avoid high heels Stability ball exercises Physical therapy

Wrist tenosynovitis Carpal Tunnel DeQuervain’s

Wrist splints Therapy (OT,PT) Injection

Musculoskeletal issues Pubic symphysis pain

Pelvic stabilization exercises

Injection

Patellofemoral Syndrome Quad strengthening,

hamstring stretching

Bracing

Physical Therapy

Musculoskeletal issues Leg cramps

More related to dehydration/sodium deficits than potassium

Possible acupressure point ???

“Exercise behaviors and health conditions of runners after childbirth”

Cross-sectional survey study of 725 runners (Blyholder, 2016)

72% of regular runners continued in pregnancy

38% continued into the 3rd trimester

50% returned to running within 6 weeks of delivery

Survey Characteristics Types of exercise before

and during pregnancy

Occurrence of antenatal and postpartum MSK pain

Stress urinary incontinence

Perception of diastasisrecti

Findings Nearly 35% had MSK pain upon returning to running

91% had pain in Lumbopelvic region: low back, pelvis and/or hips

Most had h/o antenatal msk pain

Weight training during pregnancy had significantly lower risk of msk pain

Also had less stress incontinence

Diastasis less in primips vs multiparous runners

Proven Benefits of Exercise in Pregnancy

Physical:1. Maintain/improve

maternal fitness2. Control excess

weight gain, Diabetes, BP

3. Improve appearance,posture, & sleep

4. Increase energy5. Decrease LBP,

varicose veins, &water retention

Proven Benefits of Exercise in Pregnancy

Psychological:

1. Improved self-image

2. Improved sense of

control

3. Relief of tension

Mother’s Health: Discomforts of Pregnancy

Wallace, et al.

31 exercising pregnant women compared to 22 non-exercising pregnant women

↑ Self Esteem

↓ Fatigue

↓ varicosities

↓ peripheral edema

Polman, et al.

66 subjects randomized to aqua class, gym studio class, craft class or control

↑ Mood in exercising women

Mother’s Health: Back Pain Back Pain is extremely

common in pregnancy

Mota, et al: n=71 67% incidence

Prevented women from performing usual activities – 57.7%

Worsened in later pregnancy – 77.5%

Received no treatment – 93%

Treatments include: PT, support belts, pain medication, mobility aids

Mother’s Health: Back Pain

Haakstad, et al.

105 Primigravid previously sedentary women

40 min endurance + 20 min strength + stretching

No difference in pelvic girdle/ back pain

Kluge, et al.

26 v 24 controls with back pain – 10 week exercise program

Improved pain intensity and functional ability in intervention group

Mother’s Health: Blood PressureSorensen, et al.

201 preeclamptic & 383 normotensive pregnant women

↓ Risk of preeclampsia by 35%

Decreases in the risk of preeclampsia proportionate to the intensity of the activity and energy expended

Mother’s Health: DiabetesMeta-Analysis, 2015

10 studies analyzing 3,401 participants randomized to exercise intervention versus controls

25% reduced risk in the exercise group versus control group

Suggest physical activity is slightly protective. More studies needed for type, timing, duration and compliance to form guidelines

Russo, et al. Obstet Gynecol. 2015

Mother’s Health: Weight Gain

Elliott-Sale KJ et al. Pregnancy Htn, 2014

Literature Review studies with exercise weight

intervention vs. control between 1990-2013

354 studies

5 studies

- Non-randomized- Retrospective- Combined interventions- Not designed to influence weight

- 3 pregnancy- 2 postpartum

2/3 showed reduced weight

gain

More weight loss than controls

Pregnancy OutcomesLabor Decreased rate of medical

interventions

Decreased need for pain medications

Shorter labor on average

?

Kardel, et al.-Measured VO2max in 40 nullips at 35-37 weeks-Measured time between 3cm dilation and delivery-VO2max inversely related to labor time

Effects On The Fetus

Birth weight:

-Inconsistent data

-More dependent on caloric intake

-Participation in moderate to vigorous activity throughout pregnancy may enhance birth weight, while severe regimens can = lighteroffspring (Pivarnik,MSSE,92)

Effects On The Fetus

Gestation length:

-Catecholamine release with exercise raises

concerns regarding preterm labor

-NE increases strength & frequency of uterine

contractions

-Epinephrine inhibits uterine activity

-Meta-analysis (Pivarnik,MSSE, 1992) = no difference in length of gestation

Impact On Exercise Performance Greatest on weight-bearing activities

-Associated with increasing pelvic pressure

-Progressive decline is natural Elite athlete, Sue Olsen ran a 4 hour marathon when 8

1/2 months pregnant

No effect seen with nonweight-bearing exercise

Nutritional Concerns Pregnancy requires additional 300 kcal/day

Must increase intake further based on activity level

Metabolic “cost” of exercise increases throughout pregnancy as woman gets heavier

Need to monitor athletes for weight loss or lack of weight gain

Nutritional Concerns Weight gain of < 1 kg/month in second and third

trimester unacceptable

Adequate water intake

Folic acid, calcium, protein

How do I start?When should I stop?

• Hemodynamically significant heart disease• Restrictive lung disease• Incompetent cervix or cerclage• Multiple gestation at risk of premature labor• Persistent second- or third-trimester bleeding• Placenta previa after 26 weeks of gestation• Premature labor during the current pregnancy• Ruptured membranes• Preeclampsia or pregnancy-induced

hypertension• Severe anemia

Absolute Contraindications to Aerobic Exercise

ACOG Committee Opinion No. 650, Dec. 2015

Relative Contraindications• Anemia• Unevaluated maternal cardiac arrhythmia• Chronic bronchitis• Poorly controlled type 1 diabetes• Extreme morbid obesity• Extreme underweight (BMI less than 12)• History of extremely sedentary lifestyle• Intrauterine growth restriction in current pregnancy• Poorly controlled hypertension• Orthopedic limitations• Poorly controlled seizure disorder• Poorly controlled hyperthyroidism• Heavy smoker ACOG Committee Opinion No. 650, Dec. 2015

ACOG Guidelines On Exercise During Pregnancy

Regular activity preferable to intermittent (3 times/week)

Augment heat dissipation in the 1st trimester via adequate hydration, appropriate clothing, and optimal environmental surroundings

Morphologic changes are a relative contraindication to exercises that require balance, especially in 3rd trimester

ACOG Guidelines on Exercise During Pregnancy (Cont.)

Avoid any exercise with potential for abdominal trauma

Women should be aware of the decreased oxygen available for aerobic exercise and modify their workouts based on maternal symptoms

ACOG Guidelines on Exercise During Pregnancy (Cont.)

Avoid exercise in the supine position after the 1st trimester

Avoid prolonged periods of motionless standing

ACOG Guidelines on Exercise During Pregnancy (Cont.)

Pregnancy requires an additional 300 kcal/day. Therefore, ensure adequate nutrition while exercising

Many of the physiologic and morphologic changes of pregnancy persist 4-6 weeks postpartum. Thus, PREPREGNANCY exercise routines should be resumed gradually

Exercise Prescription Individualize

Emphasis on safety

Monitor maternal symptoms

No evidence that any aerobic or anaerobic activity should be avoided (except scuba)

Exercise Prescription Sedentary women:

-Frequency = Minimum of 3x/week

-Intensity = 65-75% max HR or

perceived exertion = moderately

hard

-Type = Low-impact (walking, swimming)

-Time/Duration = 30 minutes as a goal

Exercise Prescription Regular exercisers :

-Frequency = 3-5x/week

-Intensity = 65-80% max / Perceived Exertion=

moderately hard to hard

-Type = Low-impact and any prior activities

-Time/Duration = 30-60 minutes, more as tolerated

Exercise Prescription Elite athletes

-Frequency = minimum of 4-6x/week

-Intensity = 75-80% max/ PE=hard

-Type = Same as others plus some competitive activities depending on gestational age

-Time/Duration = 60-90 minutes, increase as tolerated

Postpartum Issues

When to start/resume exercise?

Risks/benefits?

What to do?

Postpartum Exercise Benefits

Increased cardiovascular fitness

Facilitate weight loss

Increase mood

Decrease anxiety & depression

More energy after exercise

Possible Concerns Lactation

Bleeding

Incontinence

Diastasis recti abdominus

Lactation and Exercise Both physiologically demanding

Older studies done on cows!

More recent research has shown that frequent, sustained, moderate to high intensity running during lactation did not impair the quantity or quality of human breast milk No increased lactic acid

No change in volume if hydrated

Keep calories at or above 1,500kcal/day

Study by Carey and Quinn showed quicker return to pre-pregnancy weight

Lactation and Exercise

No effect on milk acceptance

No effect on growth of infant

No effect on milk production

Positive effects for mom

Lactation – Stress Fracture Risk? Pregnancy and lactation may cause transient decrease

in bone mineral density and rarely osteoporosis It is unclear if women compensate for this after they stop

nursing

Significant axial bone loss after 3-4 months of lactation Caused by prolonged estrogen deficiency

Calcium losses of > 200-400mg/day

Amenorrhea is common with lactation Possible energy imbalance

Possible increased risk similar to female athlete triad

Bone Loss and Breastfeeding

Exercise can enhance bone mineralization

Spinal bone mineral density recovered once menses resumed

Increased Bleeding? Old recommendations instruct no lifting, stairs or

muscle conditioning exercises

Thought to increase bleeding

False!

Incontinence and Exercise 30-60% of pregnant women

15% of women have stress incontinence 3 months after delivery

Initiate Kegels during pregnancy

Exercise, esp weight training, may decrease risk

Kegels Routine 8-12 maximum pelvic floor

muscle contractions

2x/day at least 3x/week

Hold 6-8 seconds and add 3-4 fast contractions at end of each max contraction

Sometimes Kegels can backfire! Hypertonicity of pelvic floor is a separate issue often seen

Diastasis Recti Split of rectus abdominus along linea alba

66% in 3rd trimester

53% immediate postpartum

36% 5-7 weeks postpartum

More likely to be absent in those who exercised prior to & during pregnancy

Abdominal Exercises Postpartum Use caution as decreased ability of abs to stabilize

pelvis during pregnancy and initial postpartum period

Avoid high torque exercises to maintain pelvic stability

Weight Loss Average women retains 0.5 -1 kg body mass gained

during each subsequent pregnancy

Those who gain after delivery have worse prognosis

Weight loss > 1.5 kg/week not recommended in lactating women

Recommendations For normal vaginal deliveries, may resume mild

program of walking, pelvic floor exercises and stretching immediately

C-sections or complicated deliveries, medical clearance at 6 week checkup

Recommendations Aerobic and muscle

conditioning activities

Use FITT principle.

Start once bleeding is minimal

Perceived exertion

Increase as tolerated, avoid fatigue

Include baby in routine!

Thank you!