Pregnancy

Should pregnant women exercise?

Should pregnant women exercise?

Yes! Healthy women are encouraged throughout pregnancy

Benefits of exercise on pregnancy

• ↓ of pregnancy induced hypertension

• ↓ of gestational diabetes

Major pregnancy hormones

• Estrogen

• Progesterone

• Human chorionic gonadotropin (HCG)

• Relaxin

• Prolactin

• Oxytocin

Estrogen

• important player

• repairs uterine lining during menstrual cycle

• neuroprotectant- protects brain from brain disease

• ↑ breast size

Progesterone

• important player

• limits contractions

• maintains uterine lining

Human chorionic gonadotropin (HCG)

• regulates estrogen and progesterone

• shows up on pregnancy test (spikes in first weeks of pregnancy)

Relaxin

• biggest effect on exercise

• limits contractions

• makes joints less stable and more flexible

  • creates balance issues, ↑ soft tissue injury

Prolactin

• ↑ milk production

• also ↑ immune health

Oxytocin

• stimulates contractions at delivery

• “induced labor” is done with a derivative of oxytocin

• ↓ stress

  • post birth baby/ mama hug

1st trimester

• hormones fluctuate

  • causes nausea/ morning sickness

• breasts swell and become tender

• ↑ perspiration

  • important to track hydration

• ↑ pressure on bladder as baby grows

2nd trimester

• body adjusts to hormone levels (less nausea)

• enlarging fetus (causes back pain, COM changes)

• joints become less stable (relaxin!)

• uterus and fetus are displaced out of pelvis

• edema

3rd trimester

• fetus continues to grow—organs get crowded out

• ↑ weight strain on heart and lungs

• Braxton-Hicks contractions (starts midway through pregnancy→ delivery)

Pre-pregnancy BMI

Being under/ overweight/ obese pre-pregnancy can cause:

• ↑ difficulty in conceiving

• ↑ risk of complications

Risk factors and BMI

risk factors ↑ linearly as BMI ↑

• gestational diabetes

• hypertension

• preeclampsia

Healthy weight gain

• single fetus: 25-35 lbs gained

• multiple fetuses: 35-45 lbs gained

Greatest predictor of infant health is ___________

birth weight

Birth weight correlated with _______

maternal weight gain

Distribution of weight gain

Most weight gain is due to average baby’s weight and the extra stored protein, fat, other nutrients

Increased responses to acute exercise (pre-pregnancy vs during)

• VO2

• HR

• SV

• Q

• TV

• V_E

• V_E/ VO2

• V_E/ VCO2

Decreased responses to acute exercise (pre-pregnancy vs during)

• SBP

• DBP

(these can also stay the same lol)

Exercise recommendations

• Moderate intensity

• >150 min

• 3+ days/ week

Exercise during pregnancy reduces odds of developing…

• complications

• post-partum depression

Exercise testing

• NO maximal tests (unless medically necessary)

• Use submaximal test to predict VO2 max

• Need medical clearance if previously sedentary or have other chronic conditions

Exercise programming

Focus on target HR and talk test

Pregnancy Target HR

• Based on fitness level and BMI

• BMI above vs below 25 kg/ m²

Resistance training

• Use low weight

• ↑ reps, ↓ sets

• easy exercises, minimal equipment

• don’t do too much

Risks of high-intensity exercise

• ↑ core body temp

• interrupted blood flow to fetus

• ↓ O2 delivery to fetus

• low birth weight

Special considerations

• avoid contact sports/ activities

• avoid exercising in supine position (after 1st trimester)

• exercise in thermoneutral environment

• avoid isometric contractions