Exercise in special populations

Pregnancy & Pulses - Bumps on the Move

• Physiological Adaptations: ↑ Cardiac output, ↑ plasma volume, ↑ resting heart rate, ↑ minute ventilation. ↓ Functional residual capacity.
• Benefits: ↓ Gestational diabetes risk, ↓ pre-eclampsia, ↓ cesarean birth rates, improved postpartum recovery.
• ACOG Recommendations: ≥150 mins/week of moderate-intensity aerobic activity.
• Modifications:
  • Avoid supine positions after 20 weeks gestation (aortocaval compression).
  • Avoid high-impact, contact sports, and activities with a high risk of falling.

⭐ High-Yield: Supine hypotension syndrome! After mid-pregnancy, the gravid uterus can compress the inferior vena cava, reducing venous return and cardiac output.

• Absolute Contraindications:
  • Restrictive lung disease
  • Severe anemia
  • Preeclampsia / pregnancy-induced hypertension
  • Placenta previa after 26 weeks

Geriatric Gains - Golden Year Fitness

• Physiological Decline: Age-related loss of muscle mass (sarcopenia), ↓ bone mineral density (osteoporosis), ↓ maximal oxygen uptake ($VO_2$ max), and ↓ flexibility.
• Exercise Benefits:
  • Strength Training: Mitigates sarcopenia, improves glycemic control, ↑ bone density.
  • Aerobic Exercise: Enhances cardiovascular function, ↑ $VO_2$ max, improves mood.
  • Balance & Flexibility: Crucial for preventing falls and maintaining activities of daily living (ADLs).

⭐ High-Yield: Regular, multicomponent exercise (aerobic, strength, balance) can reduce fall risk in community-dwelling older adults by ~25-30%.

Sweet Sweat - The Glucose Grind

• Exercise in Type 2 Diabetes (T2DM): A cornerstone of management, enhancing glucose uptake via insulin-independent mechanisms.
• Mechanism: AMPK-Mediated GLUT-4 Translocation
  • Muscle contraction ↑AMP/ATP ratio, activating AMP-activated protein kinase (AMPK).
  • AMPK stimulates GLUT-4 vesicles to move to the muscle cell surface, increasing glucose transport into the cell.

⭐ Exercise lowers blood glucose even with significant insulin resistance because the AMPK pathway for GLUT-4 translocation is separate from the insulin signaling pathway.

• Key Benefits:
  • ↓ HbA1c & blood glucose levels.
  • ↑ Insulin sensitivity.
  • Improved cardiovascular risk factors (↓BP, better lipids).
• ⚠️ Precautions:
  • Hypoglycemia: Monitor glucose, especially if on insulin or sulfonylureas.
  • Screening: Check for retinopathy, neuropathy, and nephropathy before starting intense exercise. Proper footwear is critical.

Cardiac & Pulmonary Rehab - Breaths & Beats

• Primary Goal: ↑ functional capacity, ↓ symptoms (dyspnea, angina), & improve quality of life.
• Core Components:
  • Exercise Prescription: Aerobic (3-5x/week), resistance (2-3x/week), flexibility.
  • Education: Risk factor modification (lipids, BP, smoking cessation).
  • Psychosocial: Counseling for depression/anxiety.
• Cardiac Rehab Indications: Post-MI, stable angina/HF, post-PCI/CABG.
• Pulmonary Rehab Indications: COPD, interstitial lung disease, cystic fibrosis.
  • Includes breathing retraining (pursed-lip, diaphragmatic).
• Absolute Contraindications:
  • Unstable angina or MI within 48 hours.
  • Decompensated HF.
  • Severe, symptomatic aortic stenosis.
  • Uncontrolled arrhythmia.

⭐ Cardiac rehab is proven to reduce all-cause mortality by ~25% in patients post-MI.

High-Yield Points - ⚡ Biggest Takeaways

• In pregnancy, avoid supine exercise after the first trimester to prevent aortocaval compression.
• For type 1 diabetics, exercise enhances insulin sensitivity but carries a risk of hypoglycemia; adjust insulin dose.
• Pre-treat exercise-induced bronchoconstriction with a short-acting beta-agonist (SABA) and ensure a proper cool-down.
• In older adults, focus on resistance and balance training to combat sarcopenia and prevent falls.
• Exercise improves cardiometabolic health in obesity, even without major weight loss.
• In hypertension, regular aerobic activity lowers blood pressure; avoid the Valsalva maneuver.